Follow-up to CASSANDRA-20228:

- Fix waiting state callback computes different route to initiator
 - Invariants.checkX -> Invariants.requireX (to allow complementary Invariants.expectX as appropriate)

patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20228

Follow-up to CASSANDRA-20228:
 - Fix AccordUpdateParameters to correctly supply List cell paths derived from applyAt
 - Fix ExecuteAtSerialize.serialiseNullable
 - Fix topologies flush regression caused by markRetired forcing a flush on every call

patch by Benedict; reviewed by Ariel Weisberg for CASSANDRA-20228

modules/accord

@@ -1 +1 @@
-Subproject commit 41aacd31c93251043154b5f73239345ee68b7957
+Subproject commit c7a789b1f424771a4befab6bcb91edd4ab5d7198

src/java/org/apache/cassandra/config/AccordSpec.java

@@ -272,7 +272,7 @@ public class AccordSpec
                 return units.convert(nanos, TimeUnit.NANOSECONDS);
 
             long flushPeriodNanos = flushPeriod(TimeUnit.NANOSECONDS);
-            Invariants.checkState(flushPeriodNanos > 0);
+            Invariants.require(flushPeriodNanos > 0);
             nanos = periodicFlushLagBlock.to(TimeUnit.NANOSECONDS) + flushPeriodNanos;
             // it is possible for this to race and cache the wrong value after an update
             flushCombinedBlockPeriod = nanos;

src/java/org/apache/cassandra/cql3/UpdateParameters.java

@@ -51,10 +51,9 @@ public class UpdateParameters
     public final TableMetadata metadata;
     public final ClientState clientState;
     public final QueryOptions options;
-    public final boolean constructingAccordBaseUpdate;
 
     private final long nowInSec;
-    private final long timestamp;
+    protected final long timestamp;
     private final int ttl;
 
     private final DeletionTime deletionTime;
@@ -75,18 +74,6 @@ public class UpdateParameters
                             long nowInSec,
                             int ttl,
                             Map<DecoratedKey, Partition> prefetchedRows) throws InvalidRequestException
-    {
-        this(metadata, clientState, options, timestamp, nowInSec, ttl, prefetchedRows, false);
-    }
-
-    public UpdateParameters(TableMetadata metadata,
-                            ClientState clientState,
-                            QueryOptions options,
-                            long timestamp,
-                            long nowInSec,
-                            int ttl,
-                            Map<DecoratedKey, Partition> prefetchedRows,
-                            boolean constructingAccordBaseUpdate) throws InvalidRequestException
     {
         this.metadata = metadata;
         this.clientState = clientState;
@@ -104,8 +91,6 @@ public class UpdateParameters
         // it to avoid potential confusion.
         if (timestamp == Long.MIN_VALUE)
             throw new InvalidRequestException(String.format("Out of bound timestamp, must be in [%d, %d]", Long.MIN_VALUE + 1, Long.MAX_VALUE));
-
-        this.constructingAccordBaseUpdate = constructingAccordBaseUpdate;
     }
 
     public <V> void newRow(Clustering<V> clustering) throws InvalidRequestException

src/java/org/apache/cassandra/cql3/statements/ModificationStatement.java

@@ -969,8 +969,8 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                                            local,
                                                            timestamp,
                                                            nowInSeconds,
-                                                           requestTime,
+                                                           requestTime
-                                                           constructingAccordBaseUpdate);
+            );
             for (ByteBuffer key : keys)
             {
                 Validation.validateKey(metadata(), key);
@@ -994,7 +994,7 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
             if (restrictions.hasClusteringColumnsRestrictions() && clusterings.isEmpty())
                 return;
 
-            UpdateParameters params = makeUpdateParameters(keys, clusterings, state, options, local, timestamp, nowInSeconds, requestTime, constructingAccordBaseUpdate);
+            UpdateParameters params = makeUpdateParameters(keys, clusterings, state, options, local, timestamp, nowInSeconds, requestTime);
 
             for (ByteBuffer key : keys)
             {
@@ -1052,8 +1052,7 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                                   boolean local,
                                                   long timestamp,
                                                   long nowInSeconds,
-                                                  Dispatcher.RequestTime requestTime,
+                                                  Dispatcher.RequestTime requestTime)
-                                                  boolean constructingAccordBaseUpdate)
     {
         if (clusterings.contains(Clustering.STATIC_CLUSTERING))
             return makeUpdateParameters(keys,
@@ -1064,8 +1063,8 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                         local,
                                         timestamp,
                                         nowInSeconds,
-                                        requestTime,
+                                        requestTime
-                                        constructingAccordBaseUpdate);
+            );
 
         return makeUpdateParameters(keys,
                                     new ClusteringIndexNamesFilter(clusterings, false),
@@ -1075,8 +1074,8 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                     local,
                                     timestamp,
                                     nowInSeconds,
-                                    requestTime,
+                                    requestTime
-                                    constructingAccordBaseUpdate);
+        );
     }
 
     private UpdateParameters makeUpdateParameters(Collection<ByteBuffer> keys,
@@ -1087,8 +1086,7 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                                   boolean local,
                                                   long timestamp,
                                                   long nowInSeconds,
-                                                  Dispatcher.RequestTime requestTime,
+                                                  Dispatcher.RequestTime requestTime)
-                                                  boolean constructingAccordBaseUpdate)
     {
         // Some lists operation requires reading
         Map<DecoratedKey, Partition> lists =
@@ -1106,8 +1104,7 @@ public abstract class ModificationStatement implements CQLStatement.SingleKeyspa
                                     getTimestamp(timestamp, options),
                                     nowInSeconds,
                                     getTimeToLive(options),
-                                    lists,
+                                    lists);
-                                    constructingAccordBaseUpdate);
     }
 
     public static abstract class Parsed extends QualifiedStatement

src/java/org/apache/cassandra/cql3/terms/Lists.java

@@ -44,7 +44,6 @@ import org.apache.cassandra.db.marshal.AbstractType;
 import org.apache.cassandra.db.marshal.Int32Type;
 import org.apache.cassandra.db.marshal.ListType;
 import org.apache.cassandra.db.marshal.MultiElementType;
-import org.apache.cassandra.db.marshal.TimeUUIDType;
 import org.apache.cassandra.db.rows.Cell;
 import org.apache.cassandra.db.rows.CellPath;
 import org.apache.cassandra.db.rows.ComplexColumnData;
@@ -52,7 +51,6 @@ import org.apache.cassandra.db.rows.Row;
 import org.apache.cassandra.exceptions.InvalidRequestException;
 import org.apache.cassandra.schema.ColumnMetadata;
 import org.apache.cassandra.utils.ByteBufferUtil;
-import org.apache.cassandra.utils.TimeUUID;
 
 import static org.apache.cassandra.cql3.statements.RequestValidations.checkFalse;
 import static org.apache.cassandra.cql3.statements.RequestValidations.invalidRequest;
@@ -68,13 +66,6 @@ public abstract class Lists
     @SuppressWarnings("unused")
     private static final Logger logger = LoggerFactory.getLogger(Lists.class);
 
-    /**
-     * Sentinel value indicating the cell path should be replaced by Accord with one based on the transaction executeAt
-     */
-    private static final TimeUUID ACCORD_CELL_PATH_SENTINEL_UUID = TimeUUID.atUnixMicrosWithLsb(0, 0);
-    public static final CellPath ACCORD_DUMMY_CELL_PATH = CellPath.create(ACCORD_CELL_PATH_SENTINEL_UUID.toBytes());
-    private static final long ACCORD_CELL_PATH_SENTINEL_MSB = ACCORD_CELL_PATH_SENTINEL_UUID.msb();
-
     private Lists() {}
 
     public static ColumnSpecification indexSpecOf(ColumnSpecification column)
@@ -160,33 +151,6 @@ public abstract class Lists
         return type == null ? null : ListType.getInstance(type, false);
     }
 
-    /**
-     * Return a function that given a cell with an ACCORD_CELL_PATH_SENTINEL_MSB will
-     * return a new CellPath with a TimeUUID that increases monotonically every time it is called or
-     * the existing cell path if path does not contain ACCORD_CELL_PATH_SENTINEL_MSB.
-     *
-     * Only intended to work with list cell paths where list append needs a timestamp based on the executeAt
-     * of the Accord transaction appending the cell.
-     * @param timestampMicros executeAt timestamp to use as the MSB for generated cell paths
-     */
-    public static com.google.common.base.Function<Cell, CellPath> accordListPathSupplier(long timestampMicros)
-    {
-        return new com.google.common.base.Function<Cell, CellPath>()
-        {
-            final long timeUuidMsb = TimeUUID.unixMicrosToMsb(timestampMicros);
-            long cellIndex = 0;
-            @Override
-            public CellPath apply(Cell cell)
-            {
-                CellPath path = cell.path();
-                if (ACCORD_CELL_PATH_SENTINEL_MSB == path.get(0).getLong(0))
-                    return CellPath.create(ByteBuffer.wrap(TimeUUID.toBytes(timeUuidMsb, TimeUUIDType.signedBytesToNativeLong(cellIndex++))));
-                else
-                    return path;
-            }
-        };
-    }
-
     public static class Literal extends Term.Raw
     {
         private final List<Term.Raw> elements;
@@ -463,17 +427,10 @@ public abstract class Lists
                 // during SSTable write.
                 Guardrails.itemsPerCollection.guard(type.collectionSize(elements), column.name.toString(), false, params.clientState);
 
-                long cellIndex = 0;
                 int dataSize = 0;
                 for (ByteBuffer buffer : elements)
                 {
-                    ByteBuffer cellPath;
+                    ByteBuffer cellPath = ByteBuffer.wrap(params.nextTimeUUIDAsBytes());
-                    // Accord will need to replace this value later once it knows the executeAt timestamp
-                    // so just put a TimeUUID with MSB sentinel for now
-                    if (params.constructingAccordBaseUpdate)
-                        cellPath = TimeUUID.atUnixMicrosWithLsb(0, cellIndex++).toBytes();
-                    else
-                        cellPath = ByteBuffer.wrap(params.nextTimeUUIDAsBytes());
                     Cell<?> cell = params.addCell(column, CellPath.create(cellPath), buffer);
                     dataSize += cell.dataSize();
                 }

src/java/org/apache/cassandra/db/compaction/CompactionIterator.java

@@ -905,7 +905,7 @@ public class CompactionIterator extends CompactionInfo.Holder implements Unfilte
                 AccordJournal.Builder commandBuilder = (AccordJournal.Builder) builder;
                 if (commandBuilder.isEmpty())
                 {
-                    Invariants.checkState(rows.isEmpty());
+                    Invariants.require(rows.isEmpty());
                     return partition;
                 }
 
@@ -954,9 +954,9 @@ public class CompactionIterator extends CompactionInfo.Holder implements Unfilte
 
             if (lastOffset != -1)
             {
-                Invariants.checkState(descriptor <= lastDescriptor,
+                Invariants.require(descriptor <= lastDescriptor,
                                       "Descriptors were accessed out of order: %d was accessed after %d", descriptor, lastDescriptor);
-                Invariants.checkState(descriptor != lastDescriptor ||
+                Invariants.require(descriptor != lastDescriptor ||
                                       offset < lastOffset,
                                       "Offsets within %s were accessed out of order: %d was accessed after %s", offset, lastOffset);
             }

src/java/org/apache/cassandra/db/marshal/ByteArrayAccessor.java

@@ -108,7 +108,7 @@ public class ByteArrayAccessor implements ValueAccessor<byte[]>
     @Override
     public byte[] slice(byte[] input, int offset, int length)
     {
-        Invariants.checkArgument(offset + length <= input.length);
+        Invariants.requireArgument(offset + length <= input.length);
         return Arrays.copyOfRange(input, offset, offset + length);
     }
 

src/java/org/apache/cassandra/db/marshal/CompositeType.java

@@ -312,9 +312,9 @@ public class CompositeType extends AbstractCompositeType
         byte[] result = Arrays.copyOf(bytes, c);
         if (bytes != tmpBytes) tmpFlattenBuffer.set(bytes);
         byte[] test = super.asFlatComparableBytes(accessor, data, version);
-        if (Invariants.isParanoid() && Invariants.testParanoia(LINEAR, CONSTANT, LOW)) Invariants.checkState(Arrays.equals(test, result));
+        if (Invariants.isParanoid() && Invariants.testParanoia(LINEAR, CONSTANT, LOW)) Invariants.require(Arrays.equals(test, result));
         V roundtrip = fromComparableBytes(accessor, ByteSource.peekable(ByteSource.of(result, version)), version);
-        Invariants.checkState(accessor.compare(data, roundtrip, accessor) == 0);
+        Invariants.require(accessor.compare(data, roundtrip, accessor) == 0);
         return result;
     }
 

src/java/org/apache/cassandra/db/virtual/AccordDebugKeyspace.java

@@ -578,7 +578,7 @@ public class AccordDebugKeyspace extends VirtualKeyspace
             CommandStoreTxnBlockedGraph.TxnState txn = shard.txns.get(txnId);
             if (txn == null)
             {
-                Invariants.checkState(reason == Reason.Self, "Txn %s unknown for reason %s", txnId, reason);
+                Invariants.require(reason == Reason.Self, "Txn %s unknown for reason %s", txnId, reason);
                 return;
             }
             // was it applied?  If so ignore it

src/java/org/apache/cassandra/dht/AccordBytesSplitter.java

@@ -26,7 +26,7 @@ import accord.utils.Invariants;
 import org.apache.cassandra.service.accord.api.AccordRoutingKey;
 import org.apache.cassandra.service.accord.api.AccordRoutingKey.SentinelKey;
 
-import static accord.utils.Invariants.checkArgument;
+import static accord.utils.Invariants.requireArgument;
 import static java.math.BigInteger.ONE;
 import static java.math.BigInteger.ZERO;
 
@@ -50,9 +50,9 @@ public class AccordBytesSplitter extends AccordSplitter
         // Since BOP is already not working/supported I think it's fine to punt on this.
         if (bytesLength == 0)
         {
-            checkArgument(ranges.size() <= 1);
+            requireArgument(ranges.size() <= 1);
-            checkArgument(ranges.isEmpty() || ranges.get(0).start().getClass() == SentinelKey.class);
+            requireArgument(ranges.isEmpty() || ranges.get(0).start().getClass() == SentinelKey.class);
-            checkArgument(ranges.isEmpty() || ranges.get(0).end().getClass() == SentinelKey.class);
+            requireArgument(ranges.isEmpty() || ranges.get(0).end().getClass() == SentinelKey.class);
             // Intentionally does not match 16 that is used by ServerTestUtils.getRandomToken to elicit breakage
             bytesLength = 8;
         }
@@ -75,7 +75,7 @@ public class AccordBytesSplitter extends AccordSplitter
     BigInteger valueForToken(Token token)
     {
         byte[] bytes = ((ByteOrderedPartitioner.BytesToken) token).token;
-        checkArgument(bytes.length <= byteLength);
+        requireArgument(bytes.length <= byteLength);
         BigInteger value = ZERO;
         for (int i = 0 ; i < bytes.length ; ++i)
             value = value.add(BigInteger.valueOf(bytes[i] & 0xffL).shiftLeft((byteLength - 1 - i) * 8));
@@ -85,7 +85,7 @@ public class AccordBytesSplitter extends AccordSplitter
     @Override
     Token tokenForValue(BigInteger value)
     {
-        Invariants.checkArgument(value.compareTo(ZERO) >= 0);
+        Invariants.requireArgument(value.compareTo(ZERO) >= 0);
         byte[] bytes = new byte[byteLength];
         for (int i = 0 ; i < bytes.length ; ++i)
             bytes[i] = value.shiftRight((byteLength - 1 - i) * 8).byteValue();

src/java/org/apache/cassandra/dht/LocalCompositePrefixPartitioner.java

@@ -81,7 +81,7 @@ public class LocalCompositePrefixPartitioner extends LocalPartitioner
         @Override
         public int compareTo(Token o)
         {
-            Invariants.checkArgument(o instanceof AbstractCompositePrefixToken);
+            Invariants.requireArgument(o instanceof AbstractCompositePrefixToken);
             AbstractCompositePrefixToken that = (AbstractCompositePrefixToken) o;
             CompositeType comparator = comparatorForPrefixLength(Math.min(this.prefixSize(), that.prefixSize()));
             return comparator.compare(this.token, that.token);
@@ -136,7 +136,7 @@ public class LocalCompositePrefixPartitioner extends LocalPartitioner
         public PrefixToken(ByteBuffer token, int prefixSize)
         {
             super(token);
-            Invariants.checkArgument(prefixSize > 0);
+            Invariants.requireArgument(prefixSize > 0);
             this.prefixSize = prefixSize;
         }
 
@@ -231,7 +231,7 @@ public class LocalCompositePrefixPartitioner extends LocalPartitioner
 
     public DecoratedKey decoratedKey(Object... values)
     {
-        Invariants.checkArgument(values.length == prefixComparators.size());
+        Invariants.requireArgument(values.length == prefixComparators.size());
         ByteBuffer key = createPrefixKey(values);
         return decorateKey(key);
     }

src/java/org/apache/cassandra/dht/OrderPreservingPartitioner.java

@@ -48,7 +48,7 @@ import org.apache.cassandra.utils.FBUtilities;
 import org.apache.cassandra.utils.ObjectSizes;
 import org.apache.cassandra.utils.Pair;
 
-import static accord.utils.Invariants.checkArgument;
+import static accord.utils.Invariants.requireArgument;
 import static java.lang.Integer.max;
 import static java.math.BigInteger.ONE;
 import static java.math.BigInteger.ZERO;
@@ -330,7 +330,7 @@ public class OrderPreservingPartitioner implements IPartitioner
             BigInteger valueForToken(Token token)
             {
                 String chars = ((StringToken) token).token;
-                checkArgument(chars.length() <= charLength);
+                requireArgument(chars.length() <= charLength);
                 BigInteger value = ZERO;
                 for (int i = 0 ; i < chars.length() ; ++i)
                     value = value.add(BigInteger.valueOf(chars.charAt(i) & 0xffffL).shiftLeft((charLength - 1 - i) * 16));
@@ -341,7 +341,7 @@ public class OrderPreservingPartitioner implements IPartitioner
             Token tokenForValue(BigInteger value)
             {
                 // TODO (required): test
-                checkArgument(value.compareTo(ZERO) >= 0);
+                requireArgument(value.compareTo(ZERO) >= 0);
                 char[] chars = new char[charLength];
                 for (int i = 0 ; i < chars.length ; ++i)
                     chars[i] = (char) value.shiftRight((charLength - 1 - i) * 16).shortValue();

src/java/org/apache/cassandra/journal/EntrySerializer.java

@@ -40,8 +40,8 @@ public final class EntrySerializer
     {
         int start = out.position();
         int totalSize = out.getInt() - start;
-        Invariants.checkState(totalSize == TypeSizes.INT_SIZE + out.remaining());
+        Invariants.require(totalSize == TypeSizes.INT_SIZE + out.remaining());
-        Invariants.checkState(totalSize == headerSize(keySupport, userVersion) + record.remaining() + TypeSizes.INT_SIZE);
+        Invariants.require(totalSize == headerSize(keySupport, userVersion) + record.remaining() + TypeSizes.INT_SIZE);
 
         keySupport.serialize(key, out, userVersion);
 
@@ -50,7 +50,7 @@ public final class EntrySerializer
 
         int recordSize = record.remaining();
         int recordEnd = out.position() + recordSize;
-        Invariants.checkState(out.limit() == recordEnd + TypeSizes.INT_SIZE);
+        Invariants.require(out.limit() == recordEnd + TypeSizes.INT_SIZE);
         ByteBufferUtil.copyBytes(record, record.position(), out, out.position(), recordSize);
 
         // update and write crcs
@@ -77,7 +77,7 @@ public final class EntrySerializer
         int start = from.position();
         {
             int totalSize = from.getInt(start) - start;
-            Invariants.checkState(totalSize == from.remaining());
+            Invariants.require(totalSize == from.remaining());
 
             CRC32 crc = Crc.crc32();
             int headerSize = EntrySerializer.headerSize(keySupport, userVersion);

src/java/org/apache/cassandra/journal/Flusher.java

@@ -275,7 +275,7 @@ final class Flusher<K, V>
 
             if (flushPeriodNanos <= 0)
             {
-                Invariants.checkState(params.flushMode() != PERIODIC);
+                Invariants.require(params.flushMode() != PERIODIC);
                 haveWork.acquire(1);
             }
             else
@@ -517,7 +517,7 @@ final class Flusher<K, V>
                 signal.awaitThrowUncheckedOnInterrupt();
 
                 Journal.State state = journal.state.get();
-                Invariants.checkState(state == Journal.State.NORMAL,
+                Invariants.require(state == Journal.State.NORMAL,
                                       "Thread %s outlived journal, which is in %s state", Thread.currentThread(), state);
             }
             else

src/java/org/apache/cassandra/journal/Journal.java

@@ -197,7 +197,7 @@ public class Journal<K, V> implements Shutdownable
 
     public void start()
     {
-        Invariants.checkState(state.compareAndSet(State.UNINITIALIZED, State.INITIALIZING),
+        Invariants.require(state.compareAndSet(State.UNINITIALIZED, State.INITIALIZING),
                               "Unexpected journal state during initialization", state);
         metrics.register(flusher);
 
@@ -216,7 +216,7 @@ public class Journal<K, V> implements Shutdownable
         releaser = executorFactory().sequential(name + "-releaser");
         allocator = executorFactory().infiniteLoop(name + "-allocator", new AllocateRunnable(), SAFE, NON_DAEMON, SYNCHRONIZED);
         advanceSegment(null);
-        Invariants.checkState(state.compareAndSet(State.INITIALIZING, State.NORMAL),
+        Invariants.require(state.compareAndSet(State.INITIALIZING, State.NORMAL),
                               "Unexpected journal state after initialization", state);
         flusher.start();
         compactor.start();
@@ -252,7 +252,7 @@ public class Journal<K, V> implements Shutdownable
     {
         try
         {
-            Invariants.checkState(state.compareAndSet(State.NORMAL, State.SHUTDOWN),
+            Invariants.require(state.compareAndSet(State.NORMAL, State.SHUTDOWN),
                                   "Unexpected journal state while trying to shut down", state);
             allocator.shutdown();
             wakeAllocator(); // Wake allocator to force it into shutdown
@@ -268,7 +268,7 @@ public class Journal<K, V> implements Shutdownable
             releaser.awaitTermination(1, TimeUnit.MINUTES);
             closeAllSegments();
             metrics.deregister();
-            Invariants.checkState(state.compareAndSet(State.SHUTDOWN, State.TERMINATED),
+            Invariants.require(state.compareAndSet(State.SHUTDOWN, State.TERMINATED),
                                   "Unexpected journal state while trying to shut down", state);
         }
         catch (InterruptedException e)
@@ -774,7 +774,7 @@ public class Journal<K, V> implements Shutdownable
         else
         {
             Segment<K, V> segment = segments().get(timestamp);
-            Invariants.checkState(segment != null, "Segment %d expected to be found, but neither current segment %d nor in active segments", timestamp, currentSegmentTimestamp);
+            Invariants.require(segment != null, "Segment %d expected to be found, but neither current segment %d nor in active segments", timestamp, currentSegmentTimestamp);
             if (segment == null)
                 throw new IllegalArgumentException("Request the active segment " + timestamp + " but this segment does not exist");
             if (!segment.isActive())
@@ -965,7 +965,7 @@ public class Journal<K, V> implements Shutdownable
                 StaticSegment.KeyOrderReader<K> next = readers.peek();
                 if (next == null || !next.key().equals(key))
                     break;
-                Invariants.checkState(next == readers.poll());
+                Invariants.require(next == readers.poll());
 
                 reader.accept(next.descriptor.timestamp, next.offset, next.key(), next.record(), next.descriptor.userVersion);
                 if (next.advance())

src/java/org/apache/cassandra/journal/OnDiskIndex.java

@@ -171,7 +171,7 @@ final class OnDiskIndex<K> extends Index<K>
                 if (prev != -1)
                 {
                     long tmp = prev;
-                    Invariants.checkState(readOffset(offsetAndSize) < readOffset(prev),
+                    Invariants.require(readOffset(offsetAndSize) < readOffset(prev),
                                           () -> String.format("Offsets should be strictly reverse monotonic, but found %d following %d",
                                                               readOffset(offsetAndSize), readOffset(tmp)));
                 }

src/java/org/apache/cassandra/journal/Segment.java

@@ -91,7 +91,7 @@ public abstract class Segment<K, V> implements SelfRefCounted<Segment<K, V>>, Co
         int size = Index.readSize(offsetAndSize);
         if (read(offset, size, into))
         {
-            Invariants.checkState(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
+            Invariants.require(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
             consumer.accept(descriptor.timestamp, offset, id, into.value, descriptor.userVersion);
             return true;
         }
@@ -103,7 +103,7 @@ public abstract class Segment<K, V> implements SelfRefCounted<Segment<K, V>>, Co
         long offsetAndSize = index().lookUpLast(id);
         if (offsetAndSize == -1 || !read(Index.readOffset(offsetAndSize), Index.readSize(offsetAndSize), into))
             return false;
-        Invariants.checkState(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
+        Invariants.require(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
         return true;
     }
 
@@ -115,9 +115,9 @@ public abstract class Segment<K, V> implements SelfRefCounted<Segment<K, V>>, Co
         {
             int offset = Index.readOffset(all[i]);
             int size = Index.readSize(all[i]);
-            Invariants.checkState(offset < prevOffset);
+            Invariants.require(offset < prevOffset);
-            Invariants.checkState(read(offset, size, into), "Read should always return true");
+            Invariants.require(read(offset, size, into), "Read should always return true");
-            Invariants.checkState(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
+            Invariants.require(id.equals(into.key), "Index for %s read incorrect key: expected %s but read %s", descriptor, id, into.key);
             onEntry.accept(descriptor.timestamp, offset, into.key, into.value, into.userVersion);
         }
     }

src/java/org/apache/cassandra/journal/Segments.java

@@ -58,7 +58,7 @@ class Segments<K, V>
     {
         Long2ObjectHashMap<Segment<K, V>> newSegments = new Long2ObjectHashMap<>(segments);
         Segment<K, V> oldValue = newSegments.put(activeSegment.descriptor.timestamp, activeSegment);
-        Invariants.checkState(oldValue == null);
+        Invariants.require(oldValue == null);
         return new Segments<>(newSegments);
     }
 
@@ -66,16 +66,16 @@ class Segments<K, V>
     {
         Long2ObjectHashMap<Segment<K, V>> newSegments = new Long2ObjectHashMap<>(segments);
         Segment<K, V> oldValue = segments.remove(activeSegment.descriptor.timestamp);
-        Invariants.checkState(oldValue.asActive().isEmpty());
+        Invariants.require(oldValue.asActive().isEmpty());
         return new Segments<>(newSegments);
     }
 
     Segments<K, V> withCompletedSegment(ActiveSegment<K, V> activeSegment, StaticSegment<K, V> staticSegment)
     {
-        Invariants.checkArgument(activeSegment.descriptor.equals(staticSegment.descriptor));
+        Invariants.requireArgument(activeSegment.descriptor.equals(staticSegment.descriptor));
         Long2ObjectHashMap<Segment<K, V>> newSegments = new Long2ObjectHashMap<>(segments);
         Segment<K, V> oldValue = newSegments.put(staticSegment.descriptor.timestamp, staticSegment);
-        Invariants.checkState(oldValue == activeSegment, () -> String.format("old value %s != new %s", oldValue, activeSegment));
+        Invariants.require(oldValue == activeSegment, () -> String.format("old value %s != new %s", oldValue, activeSegment));
         return new Segments<>(newSegments);
     }
 
@@ -85,13 +85,13 @@ class Segments<K, V>
         for (StaticSegment<K, V> oldSegment : oldSegments)
         {
             Segment<K, V> oldValue = newSegments.remove(oldSegment.descriptor.timestamp);
-            Invariants.checkState(oldValue == oldSegment);
+            Invariants.require(oldValue == oldSegment);
         }
 
         for (StaticSegment<K, V> compactedSegment : compactedSegments)
         {
             Segment<K, V> oldValue = newSegments.put(compactedSegment.descriptor.timestamp, compactedSegment);
-            Invariants.checkState(oldValue == null);
+            Invariants.require(oldValue == null);
         }
 
         return new Segments<>(newSegments);

src/java/org/apache/cassandra/schema/TableId.java

@@ -272,7 +272,7 @@ public final class TableId implements Comparable<TableId>
         long compact = in.readUnsignedVInt();
         if (compact > 0)
             return fromLong(compact - 1);
-        Invariants.checkState(compact == 0);
+        Invariants.require(compact == 0);
         return deserialize(in);
     }
 
@@ -281,7 +281,7 @@ public final class TableId implements Comparable<TableId>
         long compact = accessor.getUnsignedVInt(src, offset);
         if (compact > 0)
             return fromLong(compact - 1);
-        Invariants.checkState(compact == 0);
+        Invariants.require(compact == 0);
         return deserialize(src, accessor, offset + 1);
     }
 

src/java/org/apache/cassandra/schema/TableMetadata.java

@@ -82,7 +82,7 @@ import org.apache.cassandra.utils.ByteBufferUtil;
 import org.apache.cassandra.utils.FBUtilities;
 import org.github.jamm.Unmetered;
 
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.require;
 import static com.google.common.collect.Iterables.any;
 import static com.google.common.collect.Iterables.transform;
 import static java.lang.String.format;
@@ -619,7 +619,7 @@ public class TableMetadata implements SchemaElement
             }
         }
 
-        checkState((params.transactionalMode == TransactionalMode.off && params.transactionalMigrationFrom == TransactionalMigrationFromMode.none) || !isCounter(), "Counters are not supported with Accord for table " + this);
+        require((params.transactionalMode == TransactionalMode.off && params.transactionalMigrationFrom == TransactionalMigrationFromMode.none) || !isCounter(), "Counters are not supported with Accord for table " + this);
     }
 
     /**

src/java/org/apache/cassandra/service/accord/AccordCache.java

@@ -66,8 +66,8 @@ import org.apache.cassandra.utils.NoSpamLogger;
 import org.apache.cassandra.utils.NoSpamLogger.NoSpamLogStatement;
 import org.apache.cassandra.utils.ObjectSizes;
 
-import static accord.utils.Invariants.checkState;
 import static accord.utils.Invariants.illegalState;
+import static accord.utils.Invariants.require;
 import static org.apache.cassandra.net.MessagingService.current_version;
 import static org.apache.cassandra.service.accord.AccordCacheEntry.Status.EVICTED;
 import static org.apache.cassandra.service.accord.AccordCacheEntry.Status.LOADED;
@@ -225,7 +225,7 @@ public class AccordCache implements CacheSize
     @VisibleForTesting
     private <K, V> void shrinkOrEvict(AccordCacheEntry<K, V> node)
     {
-        checkState(node.references() == 0);
+        require(node.references() == 0);
 
         if (shrinkingOn && node.tryShrink())
         {
@@ -243,7 +243,7 @@ public class AccordCache implements CacheSize
     @VisibleForTesting
     public <K, V> void tryEvict(AccordCacheEntry<K, V> node)
     {
-        checkState(node.references() == 0);
+        require(node.references() == 0);
 
         if (node.isNoEvict())
         {
@@ -278,7 +278,7 @@ public class AccordCache implements CacheSize
         if (logger.isTraceEnabled())
             logger.trace("Evicting {}", node);
 
-        checkState(node.isUnqueued());
+        require(node.isUnqueued());
 
         if (updateUnreferenced)
         {
@@ -296,8 +296,8 @@ public class AccordCache implements CacheSize
             owner.validateLoadEvicted(node);
 
         AccordCacheEntry<?, ?> self = node.owner.cache.remove(node.key());
-        Invariants.checkState(self.references() == 0);
+        Invariants.require(self.references() == 0);
-        checkState(self == node, "Leaked node detected; was attempting to remove %s but cache had %s", node, self);
+        require(self == node, "Leaked node detected; was attempting to remove %s but cache had %s", node, self);
         node.notifyListeners(Listener::onEvict);
         node.evicted();
     }
@@ -316,10 +316,10 @@ public class AccordCache implements CacheSize
 
     <K, V> void failedToLoad(AccordCacheEntry<K, V> node)
     {
-        Invariants.checkState(node.references() == 0);
+        Invariants.require(node.references() == 0);
         if (node.isUnqueued())
         {
-            Invariants.checkState(node.status() == EVICTED);
+            Invariants.require(node.status() == EVICTED);
             return;
         }
         node.unlink();
@@ -422,14 +422,14 @@ public class AccordCache implements CacheSize
 
             public S acquire(AccordCacheEntry<K, V> node)
             {
-                Invariants.checkState(node.owner == this);
+                Invariants.require(node.owner == this);
                 acquireExisting(node, false);
                 return adapter.safeRef(node);
             }
 
             public void recordPreAcquired(AccordSafeState<K, V> ref)
             {
-                Invariants.checkState(ref.global().owner == this);
+                Invariants.require(ref.global().owner == this);
                 incrementCacheHits();
             }
 
@@ -456,7 +456,7 @@ public class AccordCache implements CacheSize
 
                 Object prev = cache.put(key, node);
                 node.initSize(parent());
-                Invariants.checkState(prev == null, "%s not absent from cache: %s already present", key, node);
+                Invariants.require(prev == null, "%s not absent from cache: %s already present", key, node);
                 ++size;
                 node.notifyListeners(Listener::onAdd);
                 maybeShrinkOrEvictSomeNodes();
@@ -494,11 +494,11 @@ public class AccordCache implements CacheSize
 
                 AccordCacheEntry<K, V> node = cache.get(key);
 
-                checkState(!safeRef.invalidated());
+                require(!safeRef.invalidated());
-                checkState(safeRef.global() != null, "safeRef node is null for %s", key);
+                require(safeRef.global() != null, "safeRef node is null for %s", key);
-                checkState(safeRef.global() == node, "safeRef node not in map: %s != %s", safeRef.global(), node);
+                require(safeRef.global() == node, "safeRef node not in map: %s != %s", safeRef.global(), node);
-                checkState(node.references() > 0, "references (%d) are zero for %s (%s)", node.references(), key, node);
+                require(node.references() > 0, "references (%d) are zero for %s (%s)", node.references(), key, node);
-                checkState(node.isUnqueued());
+                require(node.isUnqueued());
 
                 boolean evict = false;
                 if (safeRef.hasUpdate())
@@ -1174,7 +1174,7 @@ public class AccordCache implements CacheSize
         @Override
         public Command load(AccordCommandStore commandStore, TxnId txnId)
         {
-            Invariants.checkState(!txnId.is(Txn.Kind.EphemeralRead));
+            Invariants.require(!txnId.is(Txn.Kind.EphemeralRead));
             return commandStore.loadCommand(txnId);
         }
 
@@ -1208,7 +1208,7 @@ public class AccordCache implements CacheSize
         public Object fullShrink(TxnId txnId, Command value)
         {
             if (txnId.is(Txn.Kind.EphemeralRead))
-                Invariants.checkState(value.saveStatus().compareTo(SaveStatus.ReadyToExecute) < 0);
+                Invariants.require(value.saveStatus().compareTo(SaveStatus.ReadyToExecute) < 0);
 
             try
             {

src/java/org/apache/cassandra/service/accord/AccordCacheEntry.java

@@ -84,8 +84,8 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
             LOADED.permittedFrom |= 1 << MODIFIED.ordinal();
             for (Status status : VALUES)
             {
-                Invariants.checkState((status.ordinal() & IS_LOADED) != 0 == status.loaded);
+                Invariants.require((status.ordinal() & IS_LOADED) != 0 == status.loaded);
-                Invariants.checkState(((status.ordinal() & IS_LOADED) != 0 && (status.ordinal() & IS_NESTED) != 0) == status.nested);
+                Invariants.require(((status.ordinal() & IS_LOADED) != 0 && (status.ordinal() & IS_NESTED) != 0) == status.nested);
             }
         }
 
@@ -168,7 +168,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     boolean isNested()
     {
-        Invariants.checkState(isLoaded());
+        Invariants.require(isLoaded());
         return (status & IS_NESTED) != 0;
     }
 
@@ -194,13 +194,13 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     int noEvictGeneration()
     {
-        Invariants.checkState(isNoEvict());
+        Invariants.require(isNoEvict());
         return (status >>> 8) & 0xffff;
     }
 
     int noEvictMaxAge()
     {
-        Invariants.checkState(isNoEvict());
+        Invariants.require(isNoEvict());
         return status >>> 24;
     }
 
@@ -245,7 +245,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     private void setStatus(Status newStatus)
     {
-        Invariants.checkState((newStatus.permittedFrom & (1 << (status & STATUS_MASK))) != 0, "%s not permitted from %s", newStatus, status());
+        Invariants.require((newStatus.permittedFrom & (1 << (status & STATUS_MASK))) != 0, "%s not permitted from %s", newStatus, status());
         setStatusUnsafe(newStatus);
     }
 
@@ -257,22 +257,22 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     public void initialize(V value)
     {
-        Invariants.checkState(state == null);
+        Invariants.require(state == null);
         setStatus(LOADED);
         state = value;
     }
 
     public void readyToLoad()
     {
-        Invariants.checkState(state == null);
+        Invariants.require(state == null);
         setStatus(WAITING_TO_LOAD);
         state = new WaitingToLoad();
     }
 
     public void markNoEvict(int generation, int maxAge)
     {
-        Invariants.checkState((maxAge & ~0xff) == 0);
+        Invariants.require((maxAge & ~0xff) == 0);
-        Invariants.checkState((generation & ~0xffff) == 0);
+        Invariants.require((generation & ~0xffff) == 0);
         status |= NO_EVICT;
         status |= generation << 8;
         status |= maxAge << 24;
@@ -325,7 +325,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     public <P> Loading load(BiFunction<P, Runnable, Cancellable> loadExecutor, P param, Adapter<K, V, ?> adapter, OnLoaded onLoaded)
     {
-        Invariants.checkState(is(WAITING_TO_LOAD), "%s", this);
+        Invariants.require(is(WAITING_TO_LOAD), "%s", this);
         Loading loading = ((WaitingToLoad)state).load(loadExecutor.apply(param, () -> {
             V result;
             try
@@ -346,7 +346,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     public Loading testLoad()
     {
-        Invariants.checkState(is(WAITING_TO_LOAD));
+        Invariants.require(is(WAITING_TO_LOAD));
         Loading loading = ((WaitingToLoad)state).load(() -> {});
         setStatus(LOADING);
         state = loading;
@@ -355,7 +355,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     public Loading loading()
     {
-        Invariants.checkState(is(LOADING), "%s", this);
+        Invariants.require(is(LOADING), "%s", this);
         return (Loading) state;
     }
 
@@ -363,8 +363,8 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
     // but this one is less obvious so named as to draw attention
     public V getExclusive()
     {
-        Invariants.checkState(owner == null || owner.commandStore == null || owner.commandStore.executor().isOwningThread());
+        Invariants.require(owner == null || owner.commandStore == null || owner.commandStore.executor().isOwningThread());
-        Invariants.checkState(isLoaded(), "%s", this);
+        Invariants.require(isLoaded(), "%s", this);
         if (isShrunk())
         {
             AccordCache.Type<K, V, ?> parent = owner.parent();
@@ -500,7 +500,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     protected void saved()
     {
-        Invariants.checkState(is(MODIFIED));
+        Invariants.require(is(MODIFIED));
         setStatus(LOADED);
     }
 
@@ -525,7 +525,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     private boolean tryShrink(K key, Adapter<K, V, ?> adapter)
     {
-        Invariants.checkState(!isNested());
+        Invariants.require(!isNested());
         if (isShrunk() || state == null)
             return false;
 
@@ -540,7 +540,7 @@ public class AccordCacheEntry<K, V> extends IntrusiveLinkedListNode
 
     private void inflate(AccordCommandStore commandStore, K key, Adapter<K, V, ?> adapter)
     {
-        Invariants.checkState(isShrunk());
+        Invariants.require(isShrunk());
         if (isNested())
         {
             Nested nested = (Nested) state;

src/java/org/apache/cassandra/service/accord/AccordCommandStore.java

@@ -75,7 +75,7 @@ import static accord.local.KeyHistory.SYNC;
 import static accord.primitives.Status.Committed;
 import static accord.primitives.Status.PreCommitted;
 import static accord.primitives.Status.Truncated;
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.require;
 
 public class AccordCommandStore extends CommandStore
 {
@@ -247,7 +247,7 @@ public class AccordCommandStore extends CommandStore
 
     public Caches cachesExclusive()
     {
-        Invariants.checkState(executor.isOwningThread());
+        Invariants.require(executor.isOwningThread());
         return caches;
     }
 
@@ -360,14 +360,14 @@ public class AccordCommandStore extends CommandStore
     public AccordSafeCommandStore begin(AccordTask<?> operation,
                                         @Nullable CommandsForRanges commandsForRanges)
     {
-        checkState(current == null);
+        require(current == null);
         current = AccordSafeCommandStore.create(operation, commandsForRanges, this);
         return current;
     }
 
     void setOwner(Thread thread, Thread self)
     {
-        Invariants.checkState(thread == null ? currentThread == self : currentThread == null);
+        Invariants.require(thread == null ? currentThread == self : currentThread == null);
         currentThread = thread;
         if (thread != null) CommandStore.register(this);
 
@@ -380,7 +380,7 @@ public class AccordCommandStore extends CommandStore
 
     public void complete(AccordSafeCommandStore store)
     {
-        checkState(current == store);
+        require(current == store);
         current.postExecute();
         current = null;
     }
@@ -388,7 +388,7 @@ public class AccordCommandStore extends CommandStore
     public void abort(AccordSafeCommandStore store)
     {
         checkInStore();
-        Invariants.checkState(store == current);
+        Invariants.require(store == current);
         current = null;
     }
 

src/java/org/apache/cassandra/service/accord/AccordConfigurationService.java

@@ -243,7 +243,7 @@ public class AccordConfigurationService extends AbstractConfigurationService<Acc
      */
     public synchronized void start()
     {
-        Invariants.checkState(state == State.INITIALIZED, "Expected state to be INITIALIZED but was %s", state);
+        Invariants.require(state == State.INITIALIZED, "Expected state to be INITIALIZED but was %s", state);
         state = State.LOADING;
 
         EndpointMapping snapshot = mapping;
@@ -557,7 +557,7 @@ public class AccordConfigurationService extends AbstractConfigurationService<Acc
     private synchronized void checkStarted()
     {
         State state = this.state;
-        Invariants.checkState(state == State.STARTED, "Expected state to be STARTED but was %s", state);
+        Invariants.require(state == State.STARTED, "Expected state to be STARTED but was %s", state);
     }
 
     @VisibleForTesting

src/java/org/apache/cassandra/service/accord/AccordDataStore.java

@@ -51,7 +51,7 @@ import org.apache.cassandra.tcm.ClusterMetadata;
 import org.apache.cassandra.utils.concurrent.Future;
 import org.apache.cassandra.utils.concurrent.FutureCombiner;
 
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.require;
 import static org.apache.cassandra.db.ColumnFamilyStore.FlushReason.ACCORD_TXN_GC;
 
 public class AccordDataStore implements DataStore
@@ -142,7 +142,7 @@ public class AccordDataStore implements DataStore
 
             if (firstToken != null)
             {
-                checkState(lastToken != null);
+                require(lastToken != null);
                 if (firstToken.equals(lastToken))
                 {
                     for (org.apache.cassandra.dht.Range<Token> tableRange : tableRanges)
@@ -156,7 +156,7 @@ public class AccordDataStore implements DataStore
                 }
                 else
                 {
-                    checkState(firstToken.compareTo(lastToken) < 0);
+                    require(firstToken.compareTo(lastToken) < 0);
                     org.apache.cassandra.dht.Range<Token> memtableRange = new org.apache.cassandra.dht.Range<>(firstToken, lastToken);
                     for (org.apache.cassandra.dht.Range<Token> tableRange : tableRanges)
                     {

src/java/org/apache/cassandra/service/accord/AccordExecutor.java

@@ -178,7 +178,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
 
     public AccordCache cacheExclusive()
     {
-        Invariants.checkState(isOwningThread());
+        Invariants.require(isOwningThread());
         return cache;
     }
 
@@ -270,7 +270,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
                             continue outer;
                         }
 
-                        Invariants.checkState(load != null);
+                        Invariants.require(load != null);
                         AccordCacheEntry.OnLoaded onLoaded = this;
                         ++activeLoads;
                         if (isForRange)
@@ -286,15 +286,15 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
                                 updateQueue(task);
                         }
                         Object prev = next.pollWaitingToLoad();
-                        Invariants.checkState(prev == load);
+                        Invariants.require(prev == load);
                         if (next.peekWaitingToLoad() == null)
                             break;
 
-                        Invariants.checkState(next.state() == WAITING_TO_LOAD, "Invalid state: %s", next);
+                        Invariants.require(next.state() == WAITING_TO_LOAD, "Invalid state: %s", next);
                         if (activeLoads >= maxQueuedLoads)
                             return;
                     }
-                    Invariants.checkState(next.state().compareTo(LOADING) >= 0, "Invalid state: %s", next);
+                    Invariants.require(next.state().compareTo(LOADING) >= 0, "Invalid state: %s", next);
                     updateQueue(next);
             }
         }
@@ -377,7 +377,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
 
     private Cancellable submitIOExclusive(Task parent, Runnable run)
     {
-        Invariants.checkState(isOwningThread());
+        Invariants.require(isOwningThread());
         ++tasks;
         PlainRunnable task = new PlainRunnable(null, run, null);
         // TODO (expected): adopt queue position of the submitting task
@@ -409,7 +409,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
 
     public <R> void cancel(AccordTask<R> task)
     {
-        Invariants.checkState(task.commandStore.executor() == this,
+        Invariants.require(task.commandStore.executor() == this,
                               "%s is a wrong command store for %s, should be %s",
                               this, task, task);
         submit(AccordExecutor::cancelExclusive, CancelAsync::new, task);
@@ -575,7 +575,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
                     {
                         if (task.onLoad(loaded))
                         {
-                            Invariants.checkState(task.queued() == loading);
+                            Invariants.require(task.queued() == loading);
                             task.unqueue();
                             waitingToRun(task);
                         }
@@ -627,14 +627,14 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
     @Override
     public void setCapacity(long bytes)
     {
-        Invariants.checkState(isOwningThread());
+        Invariants.require(isOwningThread());
         cache.setCapacity(bytes);
         maxWorkingCapacityInBytes = cache.capacity() + maxWorkingSetSizeInBytes;
     }
 
     public void setWorkingSetSize(long bytes)
     {
-        Invariants.checkState(isOwningThread());
+        Invariants.require(isOwningThread());
         maxWorkingSetSizeInBytes = bytes;
         maxWorkingCapacityInBytes = cache.capacity() + maxWorkingSetSizeInBytes;
         if (maxWorkingCapacityInBytes < maxWorkingSetSizeInBytes)
@@ -643,7 +643,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
 
     public void setMaxQueuedLoads(int total, int range)
     {
-        Invariants.checkState(isOwningThread());
+        Invariants.require(isOwningThread());
         maxQueuedLoads = total;
         maxQueuedRangeLoads = range;
     }
@@ -729,7 +729,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
         @Override
         protected void preRunExclusive()
         {
-            Invariants.checkState(task != null);
+            Invariants.require(task != null);
             Thread self = Thread.currentThread();
             commandStore.setOwner(self, self);
             task.preRunExclusive();
@@ -795,7 +795,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
         @Override
         public void append(Task task)
         {
-            Invariants.checkState(!next.isSet());
+            Invariants.require(!next.isSet());
             // TODO (expected): if the new task is higher priority, replace next
             next.setNext(task);
             waitingToRun.append(next);
@@ -866,9 +866,9 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
 
         public void remove(T remove)
         {
-            Invariants.checkState(super.contains(remove));
+            Invariants.require(super.contains(remove));
             super.remove(remove);
-            Invariants.checkState(!super.contains(remove));
+            Invariants.require(!super.contains(remove));
         }
 
         public boolean contains(T contains)
@@ -1074,7 +1074,7 @@ public abstract class AccordExecutor implements CacheSize, AccordCacheEntry.OnLo
         @Override
         protected void addToQueue(TaskQueue queue)
         {
-            Invariants.checkState(queue.kind == WAITING_TO_RUN);
+            Invariants.require(queue.kind == WAITING_TO_RUN);
             queue.append(this);
         }
 

src/java/org/apache/cassandra/service/accord/AccordExecutorInfiniteLoops.java

@@ -43,7 +43,7 @@ class AccordExecutorInfiniteLoops implements Shutdownable
 
     public AccordExecutorInfiniteLoops(Mode mode, int threads, IntFunction<String> name, Function<Mode, Interruptible.Task> tasks)
     {
-        Invariants.checkState(mode == RUN_WITH_LOCK ? threads == 1 : threads >= 1);
+        Invariants.require(mode == RUN_WITH_LOCK ? threads == 1 : threads >= 1);
         final LongHashSet threadIds = new LongHashSet(threads, 0.5f);
         this.loops = new Interruptible[threads];
         for (int i = 0; i < threads; ++i)

src/java/org/apache/cassandra/service/accord/AccordExecutorSimple.java

@@ -67,7 +67,7 @@ class AccordExecutorSimple extends AccordExecutor
     public AccordExecutorSimple(ReentrantLock lock, int executorId, Mode mode, int threads, IntFunction<String> name, AccordCacheMetrics metrics, ExecutorFunctionFactory loadExecutor, ExecutorFunctionFactory saveExecutor, ExecutorFunctionFactory rangeLoadExecutor, Agent agent)
     {
         super(lock, executorId, metrics, loadExecutor, saveExecutor, rangeLoadExecutor, agent);
-        Invariants.checkArgument(threads == 1);
+        Invariants.requireArgument(threads == 1);
         this.lock = lock;
         this.executor = executorFactory().sequential(name.apply(0));
 

src/java/org/apache/cassandra/service/accord/AccordFastPathCoordinator.java

@@ -117,7 +117,7 @@ public abstract class AccordFastPathCoordinator implements ChangeListener, Confi
 
         public PeerStatus onUpdate(Node.Id node, Status status)
         {
-            Invariants.checkArgument(contains(node));
+            Invariants.requireArgument(contains(node));
             PeerStatus peerStatus = new PeerStatus(node, status);
             statusMap.put(node, peerStatus);
             return peerStatus;

src/java/org/apache/cassandra/service/accord/AccordFetchCoordinator.java

@@ -155,7 +155,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
             if (that.streams.keySet().stream().anyMatch(this.streams::containsKey))
                 throw new IllegalStateException(String.format("Unable to merge: key found in multiple StreamData %s %s",
                                                               this.streams.keySet(), that.streams.keySet()));
-            Invariants.checkState(!that.streams.keySet().stream().anyMatch(this.streams::containsKey));
+            Invariants.require(!that.streams.keySet().stream().anyMatch(this.streams::containsKey));
             ImmutableMap.Builder<TokenRange, SessionInfo> builder = ImmutableMap.builder();
             builder.putAll(this.streams);
             builder.putAll(that.streams);
@@ -180,8 +180,8 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
         {
             Invariants.nonNull(range);
             Invariants.nonNull(from);
-            Invariants.checkState(this.range == null, "range was not null: %s", this.range);
+            Invariants.require(this.range == null, "range was not null: %s", this.range);
-            Invariants.checkState(this.from == null, "from was not null: %s", this.from);
+            Invariants.require(this.from == null, "from was not null: %s", this.from);
             this.range = range;
             this.from = from;
             maybeListen();
@@ -190,7 +190,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
         private void futureReceived(StreamResultFuture future)
         {
             Invariants.nonNull(future);
-            Invariants.checkState(this.future == null, "future was not null: %s", this.future);
+            Invariants.require(this.future == null, "future was not null: %s", this.future);
             this.future = future;
             maybeListen();
         }
@@ -254,7 +254,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
                 if (!session.peer.equals(to))
                     continue;
 
-                Invariants.checkState(session.getNumRequests() == 0, "Requested to send data: %s", session);
+                Invariants.require(session.getNumRequests() == 0, "Requested to send data: %s", session);
                 if (session.getNumTransfers() > 0)
                     return true;
             }
@@ -266,14 +266,14 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
         {
             try
             {
-                Invariants.checkArgument(key.domain() == Routable.Domain.Range, "Required Range but saw %s: %s", key.domain(), key);
+                Invariants.requireArgument(key.domain() == Routable.Domain.Range, "Required Range but saw %s: %s", key.domain(), key);
                 TokenRange range = (TokenRange) key;
 
                 // TODO (required): check epoch
                 // TODO (required): handle dropped tables
                 TableId tableId = range.table();
                 TableMetadata table = ClusterMetadata.current().schema.getKeyspaces().getTableOrViewNullable(tableId);
-                Invariants.checkState(table != null, "Table with id %s not found", tableId);
+                Invariants.require(table != null, "Table with id %s not found", tableId);
 
                 // TODO (required): may also be relocation
                 StreamPlan plan = new StreamPlan(StreamOperation.BOOTSTRAP, 1, false,
@@ -310,7 +310,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
             @Override
             public void serialize(Query t, DataOutputPlus out, int version)
             {
-                Invariants.checkArgument(t == noopQuery);
+                Invariants.requireArgument(t == noopQuery);
             }
 
             @Override
@@ -322,7 +322,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
             @Override
             public long serializedSize(Query t, int version)
             {
-                Invariants.checkArgument(t == noopQuery);
+                Invariants.requireArgument(t == noopQuery);
                 return 0;
             }
         };
@@ -332,7 +332,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
             @Override
             public void serialize(Update t, DataOutputPlus out, int version)
             {
-                Invariants.checkArgument(t == null);
+                Invariants.requireArgument(t == null);
             }
 
             @Override
@@ -344,7 +344,7 @@ public class AccordFetchCoordinator extends AbstractFetchCoordinator implements
             @Override
             public long serializedSize(Update t, int version)
             {
-                Invariants.checkArgument(t == null);
+                Invariants.requireArgument(t == null);
                 return 0;
             }
         };

src/java/org/apache/cassandra/service/accord/AccordJournal.java

@@ -98,7 +98,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
     static
     {
         // make noise early if we forget to update our version mappings
-        Invariants.checkState(MessagingService.current_version == MessagingService.VERSION_51, "Expected current version to be %d but given %d", MessagingService.VERSION_51, MessagingService.current_version);
+        Invariants.require(MessagingService.current_version == MessagingService.VERSION_51, "Expected current version to be %d but given %d", MessagingService.VERSION_51, MessagingService.current_version);
     }
 
     static final ThreadLocal<byte[]> keyCRCBytes = ThreadLocal.withInitial(() -> new byte[JournalKeySupport.TOTAL_SIZE]);
@@ -162,7 +162,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
 
     public AccordJournal start(Node node)
     {
-        Invariants.checkState(status == Status.INITIALIZED);
+        Invariants.require(status == Status.INITIALIZED);
         this.node = node;
         status = Status.STARTING;
         journal.start();
@@ -193,7 +193,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
     @Override
     public void shutdown()
     {
-        Invariants.checkState(status == Status.REPLAY || status == Status.STARTED, "%s", status);
+        Invariants.require(status == Status.REPLAY || status == Status.STARTED, "%s", status);
         status = Status.TERMINATING;
         journal.shutdown();
         status = Status.TERMINATED;
@@ -251,7 +251,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
             case ERASE:
                 return null;
         }
-        Invariants.checkState(builder.saveStatus() != null, "No saveSatus loaded, but next was called and cleanup was not: %s", builder);
+        Invariants.require(builder.saveStatus() != null, "No saveSatus loaded, but next was called and cleanup was not: %s", builder);
         return builder.asMinimal();
     }
 
@@ -411,7 +411,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
         builder.forceResult(orig.result());
         // We can only use strict equality if we supply result.
         Command reconstructed = builder.construct(redundantBefore);
-        Invariants.checkState(orig.equals(reconstructed),
+        Invariants.require(orig.equals(reconstructed),
                               '\n' +
                               "Original:      %s\n" +
                               "Reconstructed: %s\n" +
@@ -460,7 +460,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
 
                 JournalKey finalKey = key;
                 iter.readAllForKey(key, (segment, position, local, buffer, userVersion) -> {
-                    Invariants.checkState(finalKey.equals(local));
+                    Invariants.require(finalKey.equals(local));
                     try (DataInputBuffer in = new DataInputBuffer(buffer, false))
                     {
                         builder.deserializeNext(in, userVersion);
@@ -481,7 +481,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
                 {
                     CommandStore commandStore = commandStores.forId(key.commandStoreId);
                     Command command = builder.construct(commandStore.unsafeGetRedundantBefore());
-                    Invariants.checkState(command.saveStatus() != SaveStatus.Uninitialised,
+                    Invariants.require(command.saveStatus() != SaveStatus.Uninitialised,
                                           "Found uninitialized command in the log: %s %s", command.toString(), builder.toString());
                     Loader loader = commandStore.loader();
                     async(loader::load, command).get();
@@ -572,7 +572,7 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
 
         private static void serialize(Command command, int flags, DataOutputPlus out, int userVersion) throws IOException
         {
-            Invariants.checkState(flags != 0);
+            Invariants.require(flags != 0);
             out.writeInt(flags);
 
             int iterable = toIterableSetFields(flags);
@@ -679,8 +679,8 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
 
         public void serialize(DataOutputPlus out, RedundantBefore redundantBefore, int userVersion) throws IOException
         {
-            Invariants.checkState(mask == 0);
+            Invariants.require(mask == 0);
-            Invariants.checkState(flags != 0);
+            Invariants.require(flags != 0);
 
             int flags = validateFlags(this.flags);
             Writer.serialize(construct(redundantBefore), flags, out, userVersion);
@@ -688,9 +688,9 @@ public class AccordJournal implements accord.api.Journal, RangeSearcher.Supplier
 
         public void deserializeNext(DataInputPlus in, int userVersion) throws IOException
         {
-            Invariants.checkState(txnId != null);
+            Invariants.require(txnId != null);
             int flags = in.readInt();
-            Invariants.checkState(flags != 0);
+            Invariants.require(flags != 0);
             nextCalled = true;
             count++;
 

src/java/org/apache/cassandra/service/accord/AccordJournalTable.java

@@ -325,7 +325,7 @@ public class AccordJournalTable<K extends JournalKey, V> implements RangeSearche
                     {
                         UnfilteredRowIterator next = partitionIterator.next();
                         JournalKey partitionKeyComponents = AccordKeyspace.JournalColumns.getJournalKey(next.partitionKey());
-                        Invariants.checkState(partitionKeyComponents.commandStoreId == storeId,
+                        Invariants.require(partitionKeyComponents.commandStoreId == storeId,
                                               () -> String.format("table index returned a command store other than the exepcted one; expected %d != %d", storeId, partitionKeyComponents.commandStoreId));
                         return partitionKeyComponents.id;
                     }
@@ -372,7 +372,7 @@ public class AccordJournalTable<K extends JournalKey, V> implements RangeSearche
 
     private void readRow(K key, Unfiltered unfiltered, EntryHolder<K> into, RecordConsumer<K> onEntry)
     {
-        Invariants.checkState(unfiltered.isRow());
+        Invariants.require(unfiltered.isRow());
         Row row = (Row) unfiltered;
 
         long descriptor = LongType.instance.compose(ByteBuffer.wrap((byte[]) row.clustering().get(0)));

src/java/org/apache/cassandra/service/accord/AccordJournalValueSerializers.java

@@ -335,7 +335,7 @@ public class AccordJournalValueSerializers
                 epochs[i] = in.readLong();
                 ranges[i] = KeySerializers.ranges.deserialize(in, messagingVersion);
             }
-            Invariants.checkState(ranges.length == epochs.length);
+            Invariants.require(ranges.length == epochs.length);
             into.update(new RangesForEpoch(epochs, ranges));
         }
     }
@@ -354,7 +354,7 @@ public class AccordJournalValueSerializers
         protected NavigableMap<K, V> accumulate(NavigableMap<K, V> accumulator, V newValue)
         {
             V prev = accumulator.put(getKey.apply(newValue), newValue);
-            Invariants.checkState(prev == null || prev.equals(newValue));
+            Invariants.require(prev == null || prev.equals(newValue));
             return accumulator;
         }
     }

src/java/org/apache/cassandra/service/accord/AccordKeyspace.java

@@ -131,7 +131,7 @@ import org.apache.cassandra.utils.CloseableIterator;
 import org.apache.cassandra.utils.btree.BTreeSet;
 import org.apache.cassandra.utils.concurrent.OpOrder;
 
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.require;
 import static java.lang.String.format;
 import static java.util.Collections.emptyMap;
 import static org.apache.cassandra.cql3.QueryProcessor.executeInternal;
@@ -327,7 +327,7 @@ public class AccordKeyspace
         // TODO (expected): garbage-free filtering, reusing encoding
         public Row withoutRedundantCommands(TokenKey key, Row row, RedundantBefore.Entry redundantBefore)
         {
-            Invariants.checkState(row.columnCount() == 1);
+            Invariants.require(row.columnCount() == 1);
             Cell<?> cell = row.getCell(data);
             if (cell == null)
                 return row;
@@ -688,7 +688,7 @@ public class AccordKeyspace
 
             try (RowIterator partition = partitions.next())
             {
-                Invariants.checkState(partition.hasNext());
+                Invariants.require(partition.hasNext());
                 Row row = partition.next();
                 ByteBuffer data = cellValue(row, accessor.data);
                 return Serialize.fromBytes(key, data);
@@ -714,8 +714,8 @@ public class AccordKeyspace
 
         private EpochDiskState(long minEpoch, long maxEpoch)
         {
-            Invariants.checkArgument(minEpoch >= 0, "Min Epoch %d < 0", minEpoch);
+            Invariants.requireArgument(minEpoch >= 0, "Min Epoch %d < 0", minEpoch);
-            Invariants.checkArgument(maxEpoch >= minEpoch, "Max epoch %d < min %d", maxEpoch, minEpoch);
+            Invariants.requireArgument(maxEpoch >= minEpoch, "Max epoch %d < min %d", maxEpoch, minEpoch);
             this.minEpoch = minEpoch;
             this.maxEpoch = maxEpoch;
         }
@@ -740,14 +740,14 @@ public class AccordKeyspace
         @VisibleForTesting
         EpochDiskState withNewMaxEpoch(long epoch)
         {
-            Invariants.checkArgument(epoch > maxEpoch, "Epoch %d <= %d (max)", epoch, maxEpoch);
+            Invariants.requireArgument(epoch > maxEpoch, "Epoch %d <= %d (max)", epoch, maxEpoch);
             return EpochDiskState.create(Math.max(1, minEpoch), epoch);
         }
 
         private EpochDiskState withNewMinEpoch(long epoch)
         {
-            Invariants.checkArgument(epoch > minEpoch, "epoch %d <= %d (min)", epoch, minEpoch);
+            Invariants.requireArgument(epoch > minEpoch, "epoch %d <= %d (min)", epoch, minEpoch);
-            Invariants.checkArgument(epoch <= maxEpoch, "epoch %d > %d (max)", epoch, maxEpoch);
+            Invariants.requireArgument(epoch <= maxEpoch, "epoch %d > %d (max)", epoch, maxEpoch);
             return EpochDiskState.create(epoch, maxEpoch);
         }
 
@@ -792,7 +792,7 @@ public class AccordKeyspace
             CommandSerializers.txnId.serialize(key.id, id);
             id.flip();
             ByteBuffer pk = keyComparator.make(key.commandStoreId, (byte)key.type.id, id).serializeAsPartitionKey();
-            Invariants.checkState(getTxnId(splitPartitionKey(pk)).equals(key.id));
+            Invariants.require(getTxnId(splitPartitionKey(pk)).equals(key.id));
             return Journal.partitioner.decorateKey(pk);
         }
 
@@ -871,7 +871,7 @@ public class AccordKeyspace
     {
         if (diskState.isEmpty())
             return saveEpochDiskState(EpochDiskState.create(epoch));
-        Invariants.checkArgument(epoch >= diskState.minEpoch, "Epoch %d < %d (min)", epoch, diskState.minEpoch);
+        Invariants.requireArgument(epoch >= diskState.minEpoch, "Epoch %d < %d (min)", epoch, diskState.minEpoch);
         if (epoch > diskState.maxEpoch)
         {
             diskState = diskState.withNewMaxEpoch(epoch);
@@ -900,20 +900,16 @@ public class AccordKeyspace
         diskState = maybeUpdateMaxEpoch(diskState, epoch);
         String cql = "UPDATE " + ACCORD_KEYSPACE_NAME + '.' + TOPOLOGIES + ' ' +
                      "SET closed = closed + ? WHERE epoch = ?";
-        executeInternal(cql,
+        executeInternal(cql, KeySerializers.rangesToBlobMap(ranges), epoch);
-                        KeySerializers.rangesToBlobMap(ranges), epoch);
         return diskState;
     }
 
-    // TODO (required): unused
     public static EpochDiskState markRetired(Ranges ranges, long epoch, EpochDiskState diskState)
     {
         diskState = maybeUpdateMaxEpoch(diskState, epoch);
         String cql = "UPDATE " + ACCORD_KEYSPACE_NAME + '.' + TOPOLOGIES + ' ' +
                      "SET retired = retired + ? WHERE epoch = ?";
-        executeInternal(cql,
+        executeInternal(cql, KeySerializers.rangesToBlobMap(ranges), epoch);
-                        KeySerializers.rangesToBlobMap(ranges), epoch);
-        flush(Topologies);
         return diskState;
     }
 
@@ -979,7 +975,7 @@ public class AccordKeyspace
             consumer.load(epoch, SyncStatus.NOT_STARTED, Collections.emptySet(), Collections.emptySet(), Ranges.EMPTY, Ranges.EMPTY);
             return;
         }
-        checkState(!result.isEmpty(), "Nothing found for epoch %d", epoch);
+        require(!result.isEmpty(), "Nothing found for epoch %d", epoch);
         UntypedResultSet.Row row = result.one();
 
         SyncStatus syncStatus = row.has("sync_state")

src/java/org/apache/cassandra/service/accord/AccordSegmentCompactor.java

@@ -59,7 +59,7 @@ public class AccordSegmentCompactor<V> implements SegmentCompactor<JournalKey, V
     @Override
     public Collection<StaticSegment<JournalKey, V>> compact(Collection<StaticSegment<JournalKey, V>> segments)
     {
-        Invariants.checkState(segments.size() >= 2, () -> String.format("Can only compact 2 or more segments, but got %d", segments.size()));
+        Invariants.require(segments.size() >= 2, () -> String.format("Can only compact 2 or more segments, but got %d", segments.size()));
         logger.info("Compacting {} static segments: {}", segments.size(), segments);
 
         PriorityQueue<KeyOrderReader<JournalKey>> readers = new PriorityQueue<>();
@@ -110,9 +110,9 @@ public class AccordSegmentCompactor<V> implements SegmentCompactor<JournalKey, V
                         {
                             if (lastDescriptor != -1)
                             {
-                                Invariants.checkState(reader.descriptor.timestamp <= lastDescriptor,
+                                Invariants.require(reader.descriptor.timestamp <= lastDescriptor,
                                                       "Descriptors were accessed out of order: %d was accessed after %d", reader.descriptor.timestamp, lastDescriptor);
-                                Invariants.checkState(reader.descriptor.timestamp != lastDescriptor ||
+                                Invariants.require(reader.descriptor.timestamp != lastDescriptor ||
                                                       reader.offset() < lastOffset,
                                                       "Offsets were accessed out of order: %d was accessed after %s", reader.offset(), lastOffset);
                             }
@@ -156,7 +156,7 @@ public class AccordSegmentCompactor<V> implements SegmentCompactor<JournalKey, V
 
             if (prevKey != null)
             {
-                Invariants.checkArgument((decoratedKey.compareTo(prevDecoratedKey) >= 0 ? 1 : -1) == (JournalKey.SUPPORT.compare(key, prevKey) >= 0 ? 1 : -1),
+                Invariants.requireArgument((decoratedKey.compareTo(prevDecoratedKey) >= 0 ? 1 : -1) == (JournalKey.SUPPORT.compare(key, prevKey) >= 0 ? 1 : -1),
                                          String.format("Partition key and JournalKey didn't have matching order, which may imply a serialization issue.\n%s (%s)\n%s (%s)",
                                                        key, decoratedKey, prevKey, prevDecoratedKey));
             }

src/java/org/apache/cassandra/service/accord/AccordService.java

@@ -177,7 +177,7 @@ import org.apache.cassandra.utils.concurrent.UncheckedInterruptedException;
 import static accord.messages.SimpleReply.Ok;
 import static accord.primitives.Routable.Domain.Key;
 import static accord.primitives.Routable.Domain.Range;
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.require;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.NANOSECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
@@ -310,7 +310,7 @@ public class AccordService implements IAccordService, Shutdownable
         if (!DatabaseDescriptor.getAccordTransactionsEnabled())
             return NOOP_SERVICE;
         IAccordService i = instance;
-        Invariants.checkState(i != null, "AccordService was not started");
+        Invariants.require(i != null, "AccordService was not started");
         return i;
     }
 
@@ -324,7 +324,7 @@ public class AccordService implements IAccordService, Shutdownable
     @VisibleForTesting
     public AccordService(Id localId)
     {
-        Invariants.checkState(localId != null, "static localId must be set before instantiating AccordService");
+        Invariants.require(localId != null, "static localId must be set before instantiating AccordService");
         logger.info("Starting accord with nodeId {}", localId);
         AccordAgent agent = FBUtilities.construct(CassandraRelevantProperties.ACCORD_AGENT_CLASS.getString(AccordAgent.class.getName()), "AccordAgent");
         agent.setNodeId(localId);
@@ -702,7 +702,7 @@ public class AccordService implements IAccordService, Shutdownable
         if (success == null)
         {
             logger.error("Ran out of retries for barrier");
-            checkState(existingFailures != null, "Didn't have success, but also didn't have failures");
+            require(existingFailures != null, "Didn't have success, but also didn't have failures");
             Throwables.throwIfUnchecked(existingFailures);
             throw new RuntimeException(existingFailures);
         }
@@ -1260,7 +1260,7 @@ public class AccordService implements IAccordService, Shutdownable
         if (ranges.isEmpty()) return; // nothing to see here
 
         ColumnFamilyStore cfs = Schema.instance.getColumnFamilyStoreInstance(id);
-        Invariants.checkState(cfs != null, "Unable to find table %s", id);
+        Invariants.require(cfs != null, "Unable to find table %s", id);
         BigInteger targetSplitSize = BigInteger.valueOf(Math.max(1, cfs.estimateKeys() / 1_000_000));
 
         List<AsyncChain<?>> syncs = new ArrayList<>(ranges.size());

src/java/org/apache/cassandra/service/accord/AccordSyncPropagator.java

@@ -316,7 +316,7 @@ public class AccordSyncPropagator
             @Override
             public void onResponse(Message<SimpleReply> msg)
             {
-                Invariants.checkState(msg.payload == SimpleReply.Ok, "Unexpected message: %s", msg);
+                Invariants.require(msg.payload == SimpleReply.Ok, "Unexpected message: %s", msg);
                 Set<Long> completedEpochs = new HashSet<>();
                 // TODO review is it a good idea to call the listener while not holding the `AccordSyncPropagator` lock?
                 synchronized (AccordSyncPropagator.this)

src/java/org/apache/cassandra/service/accord/AccordTask.java

@@ -287,12 +287,12 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
 
     private void state(State state)
     {
-        Invariants.checkState(state.isPermittedFrom(this.state), "%s forbidden from %s", state, this, AccordTask::toDescription);
+        Invariants.require(state.isPermittedFrom(this.state), "%s forbidden from %s", state, this, AccordTask::toDescription);
         this.state = state;
         if (state == WAITING_TO_RUN)
         {
-            Invariants.checkState(rangeScanner == null || rangeScanner.scanned);
+            Invariants.require(rangeScanner == null || rangeScanner.scanned);
-            Invariants.checkState(loading == null && waitingToLoad == null, "WAITING_TO_RUN => no loading or waiting; found %s", this, AccordTask::toDescription);
+            Invariants.require(loading == null && waitingToLoad == null, "WAITING_TO_RUN => no loading or waiting; found %s", this, AccordTask::toDescription);
             loadedAt = nanoTime();
         }
         else if (state == RUNNING)
@@ -317,7 +317,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
             @Override
             protected Cancellable start(BiConsumer<? super R, Throwable> callback)
             {
-                Invariants.checkState(AccordTask.this.callback == null);
+                Invariants.require(AccordTask.this.callback == null);
                 AccordTask.this.callback = callback;
                 commandStore.tryPreSetup(AccordTask.this);
                 commandStore.executor().submit(AccordTask.this);
@@ -396,7 +396,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
             case RECOVER:
                 if (!isToCompleteRangeScan)
                 {
-                    Invariants.checkState(rangeScanner == null);
+                    Invariants.require(rangeScanner == null);
                     rangeScanner = new RangeTxnScanner();
                 }
 
@@ -443,7 +443,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
 
         AccordCacheEntry<K, V> node = ref.global();
         int refs = node.increment();
-        Invariants.checkState(refs > 1);
+        Invariants.require(refs > 1);
         loaded.apply(this).put(k, cache.parent().adapter().safeRef(node));
     }
 
@@ -498,7 +498,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
     public boolean onLoad(AccordCacheEntry<?, ?> state)
     {
         AccordSafeState<?, ?> safeRef = loading == null ? null : loading.remove(state.key());
-        Invariants.checkState(safeRef != null && safeRef.global() == state, "Expected to find %s loading; found %s", state, this, AccordTask::toDescription);
+        Invariants.require(safeRef != null && safeRef.global() == state, "Expected to find %s loading; found %s", state, this, AccordTask::toDescription);
         if (safeRef.getClass() == AccordSafeCommand.class)
             ensureCommands().put((TxnId)state.key(), (AccordSafeCommand) safeRef);
         else
@@ -511,7 +511,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
         if (this.state.compareTo(State.WAITING_TO_LOAD) < 0)
             return false;
 
-        Invariants.checkState(waitingToLoad == null, "Invalid state: %s", this, AccordTask::toDescription);
+        Invariants.require(waitingToLoad == null, "Invalid state: %s", this, AccordTask::toDescription);
         state(WAITING_TO_RUN);
         return true;
     }
@@ -520,7 +520,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
     public boolean onLoading(AccordCacheEntry<?, ?> state)
     {
         boolean removed = waitingToLoad != null && waitingToLoad.remove(state);
-        Invariants.checkState(removed, "%s not found in waitingToLoad %s", state, this, AccordTask::toDescription);
+        Invariants.require(removed, "%s not found in waitingToLoad %s", state, this, AccordTask::toDescription);
         if (!waitingToLoad.isEmpty())
             return false;
 
@@ -575,7 +575,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
 
     private ArrayDeque<AccordCacheEntry<?, ?>> ensureWaitingToLoad()
     {
-        Invariants.checkState(state.compareTo(WAITING_TO_LOAD) <= 0, "Expected status to be on or before WAITING_TO_LOAD; found %s", this, AccordTask::toDescription);
+        Invariants.require(state.compareTo(WAITING_TO_LOAD) <= 0, "Expected status to be on or before WAITING_TO_LOAD; found %s", this, AccordTask::toDescription);
         if (waitingToLoad == null)
             waitingToLoad = new ArrayDeque<>();
         return waitingToLoad;
@@ -583,7 +583,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
 
     public AccordCacheEntry<?, ?> pollWaitingToLoad()
     {
-        Invariants.checkState(state == State.WAITING_TO_LOAD, "Expected status to be WAITING_TO_LOAD; found %s", this, AccordTask::toDescription);
+        Invariants.require(state == State.WAITING_TO_LOAD, "Expected status to be WAITING_TO_LOAD; found %s", this, AccordTask::toDescription);
         if (waitingToLoad == null)
             return null;
 
@@ -612,7 +612,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
     {
         if (sanityCheck != null)
         {
-            Invariants.checkState(SANITY_CHECK);
+            Invariants.require(SANITY_CHECK);
             Condition condition = Condition.newOneTimeCondition();
             this.commandStore.appendCommands(diffs, condition::signal);
             condition.awaitUninterruptibly();
@@ -898,8 +898,8 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
         if (state == CANCELLED)
             return;
 
-        Invariants.checkState(queue.kind == state || (queue.kind == State.WAITING_TO_LOAD && state == WAITING_TO_SCAN_RANGES), "Invalid queue type: %s vs %s", queue.kind, this, AccordTask::toDescription);
+        Invariants.require(queue.kind == state || (queue.kind == State.WAITING_TO_LOAD && state == WAITING_TO_SCAN_RANGES), "Invalid queue type: %s vs %s", queue.kind, this, AccordTask::toDescription);
-        Invariants.checkState(this.queued == null, "Already queued with state: %s", this, AccordTask::toDescription);
+        Invariants.require(this.queued == null, "Already queued with state: %s", this, AccordTask::toDescription);
         queued = queue;
         queue.append(this);
     }
@@ -1089,7 +1089,7 @@ public abstract class AccordTask<R> extends Task implements Runnable, Function<S
 
         public void scannedExclusive()
         {
-            Invariants.checkState(state == SCANNING_RANGES, "Expected SCANNING_RANGES; found %s", AccordTask.this, AccordTask::toDescription);
+            Invariants.require(state == SCANNING_RANGES, "Expected SCANNING_RANGES; found %s", AccordTask.this, AccordTask::toDescription);
             scanned = true;
             scannedInternal();
             if (loading == null) state(WAITING_TO_RUN);

src/java/org/apache/cassandra/service/accord/AccordTopology.java

@@ -102,7 +102,7 @@ public class AccordTopology
             FastPathStrategy tableStrategy = metadata.params.fastPath;
             FastPathStrategy strategy = tableStrategy.kind() != FastPathStrategy.Kind.INHERIT_KEYSPACE
                                         ? tableStrategy : keyspace.params.fastPath;
-            Invariants.checkState(strategy.kind() != FastPathStrategy.Kind.INHERIT_KEYSPACE);
+            Invariants.require(strategy.kind() != FastPathStrategy.Kind.INHERIT_KEYSPACE);
             return strategy;
         }
 
@@ -125,11 +125,11 @@ public class AccordTopology
         {
             // TCM doesn't create wrap around ranges
             for (Range<Token> range : ranges)
-                Invariants.checkArgument(!range.isWrapAround() || range.right.equals(range.right.minValue()),
+                Invariants.requireArgument(!range.isWrapAround() || range.right.equals(range.right.minValue()),
                                          "wrap around range %s found", range);
 
             Sets.SetView<InetAddressAndPort> readOnly = Sets.difference(readEndpoints, writeEndpoints);
-            Invariants.checkState(readOnly.isEmpty(), "Read only replicas detected: %s", readOnly);
+            Invariants.require(readOnly.isEmpty(), "Read only replicas detected: %s", readOnly);
 
             SortedArrayList<Id> nodes = new SortedArrayList<>(writeEndpoints.stream()
                                                                     .map(directory::peerId)

src/java/org/apache/cassandra/service/accord/CommandsForRanges.java

@@ -227,7 +227,7 @@ public class CommandsForRanges extends TreeMap<Timestamp, Summary> implements Co
 
         public Summary ifRelevant(Command.Minimal cmd)
         {
-            Invariants.checkState(findAsDep == null);
+            Invariants.require(findAsDep == null);
             return ifRelevant(cmd.txnId, cmd.executeAt, cmd.saveStatus, cmd.participants, null);
         }
     }

src/java/org/apache/cassandra/service/accord/EndpointMapping.java

@@ -85,16 +85,16 @@ class EndpointMapping implements AccordEndpointMapper
 
         public Builder add(InetAddressAndPort endpoint, Node.Id id)
         {
-            Invariants.checkArgument(!mapping.containsKey(id), "Mapping already exists for Node.Id %s", id);
+            Invariants.requireArgument(!mapping.containsKey(id), "Mapping already exists for Node.Id %s", id);
-            Invariants.checkArgument(!mapping.containsValue(endpoint), "Mapping already exists for %s", endpoint);
+            Invariants.requireArgument(!mapping.containsValue(endpoint), "Mapping already exists for %s", endpoint);
             mapping.put(id, endpoint);
             return this;
         }
 
         public Builder removed(InetAddressAndPort endpoint, Node.Id id, long epoch)
         {
-            Invariants.checkArgument(!mapping.containsKey(id), "Mapping already exists for Node.Id %s", id);
+            Invariants.requireArgument(!mapping.containsKey(id), "Mapping already exists for Node.Id %s", id);
-            Invariants.checkArgument(!mapping.containsValue(endpoint), "Mapping already exists for %s", endpoint);
+            Invariants.requireArgument(!mapping.containsValue(endpoint), "Mapping already exists for %s", endpoint);
             mapping.put(id, endpoint);
             removed.put(id, epoch);
             return this;

src/java/org/apache/cassandra/service/accord/JournalKey.java

@@ -52,8 +52,8 @@ public final class JournalKey
 
     public JournalKey(TxnId id, Type type, int commandStoreId)
     {
-        Invariants.checkArgument(commandStoreId >= 0);
+        Invariants.requireArgument(commandStoreId >= 0);
-        Invariants.checkState((id.lsb & (0xffff & ~TxnId.IDENTITY_FLAGS)) == 0);
+        Invariants.require((id.lsb & (0xffff & ~TxnId.IDENTITY_FLAGS)) == 0);
         Invariants.nonNull(type);
         Invariants.nonNull(id);
         this.type = type;

src/java/org/apache/cassandra/service/accord/TokenRange.java

@@ -44,7 +44,7 @@ public class TokenRange extends Range.EndInclusive
 
     public static TokenRange create(AccordRoutingKey start, AccordRoutingKey end)
     {
-        Invariants.checkArgument(start.table().equals(end.table()),
+        Invariants.requireArgument(start.table().equals(end.table()),
                                  "Token ranges cannot cover more than one keyspace start:%s, end:%s",
                                  start, end);
         return new TokenRange(start, end);

src/java/org/apache/cassandra/service/accord/api/AccordAgent.java

@@ -204,7 +204,7 @@ public class AccordAgent implements Agent
         startTime = nonClashingStartTime(startTime, shard == null ? null : shard.nodes, node.id(), oneSecond, random);
         long nowMicros = MILLISECONDS.toMicros(Clock.Global.currentTimeMillis());
         long delayMicros = Math.max(1, startTime - nowMicros);
-        Invariants.checkState(delayMicros < TimeUnit.HOURS.toMicros(1L));
+        Invariants.require(delayMicros < TimeUnit.HOURS.toMicros(1L));
         return units.convert(delayMicros, MICROSECONDS);
     }
 

src/java/org/apache/cassandra/service/accord/fastpath/ParameterizedFastPathStrategy.java

@@ -199,7 +199,7 @@ public class ParameterizedFastPathStrategy implements FastPathStrategy
             cmp = this.sortPos - that.sortPos;
             if (cmp != 0) return cmp;
 
-            Invariants.checkState(this.id.equals(that.id));
+            Invariants.require(this.id.equals(that.id));
             return 0;
         }
     }
@@ -228,7 +228,7 @@ public class ParameterizedFastPathStrategy implements FastPathStrategy
 
         Arrays.sort(array);
         SortedArrayList<Node.Id> electorate = new SortedArrayList<>(array);
-        Invariants.checkState(electorate.size() >= slowQuorum);
+        Invariants.require(electorate.size() >= slowQuorum);
         return electorate;
     }
 

src/java/org/apache/cassandra/service/accord/fastpath/SimpleFastPathStrategy.java

@@ -59,7 +59,7 @@ public class SimpleFastPathStrategy implements FastPathStrategy
         Node.Id[] array = new Node.Id[nodes.size() - discarded];
         System.arraycopy(tmp, 0, array, 0, nodes.size() - discarded);
         SortedArrayList<Node.Id> fastPath = new SortedArrayList<>(array);
-        Invariants.checkState(fastPath.size() >= Shard.slowQuorumSize(nodes.size()));
+        Invariants.require(fastPath.size() >= Shard.slowQuorumSize(nodes.size()));
         return fastPath;
     }
 

src/java/org/apache/cassandra/service/accord/interop/AccordInteropApply.java

@@ -49,7 +49,7 @@ import org.apache.cassandra.service.accord.AccordMessageSink.AccordMessageType;
 import org.apache.cassandra.service.accord.serializers.ApplySerializers.ApplySerializer;
 import org.apache.cassandra.service.accord.txn.AccordUpdate;
 
-import static accord.utils.Invariants.checkState;
+import static accord.utils.Invariants.requireArgument;
 import static com.google.common.base.Preconditions.checkArgument;
 
 /**
@@ -101,7 +101,7 @@ public class AccordInteropApply extends Apply implements LocalListeners.ComplexL
     public ApplyReply apply(SafeCommandStore safeStore, StoreParticipants participants)
     {
         ApplyReply reply = super.apply(safeStore, participants);
-        checkState(reply == ApplyReply.Redundant || reply == ApplyReply.Applied || reply == ApplyReply.Insufficient, "Unexpected ApplyReply");
+        requireArgument(reply == ApplyReply.Redundant || reply == ApplyReply.Applied || reply == ApplyReply.Insufficient, "Unexpected ApplyReply");
 
         // Hasn't necessarily finished applying yet so need to check and maybe add a listener
         // Redundant means we are competing with a recovery coordinator which is fine

src/java/org/apache/cassandra/service/accord/interop/AccordInteropExecution.java

@@ -99,7 +99,7 @@ import org.apache.cassandra.transport.Dispatcher;
 
 import static accord.coordinate.CoordinationAdapter.Factory.Kind.Standard;
 import static accord.primitives.Txn.Kind.Write;
-import static accord.utils.Invariants.checkArgument;
+import static accord.utils.Invariants.requireArgument;
 import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.accordReadMetrics;
 import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.accordWriteMetrics;
 
@@ -172,7 +172,7 @@ public class AccordInteropExecution implements ReadCoordinator, MaximalCommitSen
     public AccordInteropExecution(Node node, TxnId txnId, Txn txn, AccordUpdate.Kind updateKind, FullRoute<?> route, Participants<?> readScope, Timestamp executeAt, Deps deps, BiConsumer<? super Result, Throwable> callback,
                                   AgentExecutor executor, ConsistencyLevel consistencyLevel, AccordEndpointMapper endpointMapper)
     {
-        checkArgument(!txn.read().keys().isEmpty() || updateKind == AccordUpdate.Kind.UNRECOVERABLE_REPAIR);
+        requireArgument(!txn.read().keys().isEmpty() || updateKind == AccordUpdate.Kind.UNRECOVERABLE_REPAIR);
         this.node = node;
         this.txnId = txnId;
         this.txn = txn;
@@ -183,7 +183,7 @@ public class AccordInteropExecution implements ReadCoordinator, MaximalCommitSen
         this.callback = callback;
         this.executor = executor;
 
-        checkArgument(updateKind == AccordUpdate.Kind.UNRECOVERABLE_REPAIR || consistencyLevel == ConsistencyLevel.QUORUM || consistencyLevel == ConsistencyLevel.ALL || consistencyLevel == ConsistencyLevel.SERIAL);
+        requireArgument(updateKind == AccordUpdate.Kind.UNRECOVERABLE_REPAIR || consistencyLevel == ConsistencyLevel.QUORUM || consistencyLevel == ConsistencyLevel.ALL || consistencyLevel == ConsistencyLevel.SERIAL);
         this.consistencyLevel = consistencyLevel;
         this.endpointMapper = endpointMapper;
 
@@ -242,7 +242,7 @@ public class AccordInteropExecution implements ReadCoordinator, MaximalCommitSen
     @Override
     public void sendReadRepairMutation(Message<Mutation> message, InetAddressAndPort to, RequestCallback<Object> callback)
     {
-        checkArgument(message.payload.allowsPotentialTransactionConflicts());
+        requireArgument(message.payload.allowsPotentialTransactionConflicts());
         Node.Id id = endpointMapper.mappedId(to);
         AccordInteropReadRepair readRepair = new AccordInteropReadRepair(id, executes, txnId, readScope, executeAt.epoch(), message.payload);
         node.send(id, readRepair, executor, new AccordInteropReadRepair.ReadRepairCallback(id, to, message, callback, this));

src/java/org/apache/cassandra/service/accord/interop/AccordInteropPersist.java

@@ -111,14 +111,14 @@ public class AccordInteropPersist extends Persist
     public AccordInteropPersist(Node node, Topologies topologies, TxnId txnId, Route<?> sendTo, Txn txn, Timestamp executeAt, Deps deps, Writes writes, Result result, FullRoute<?> fullRoute, ConsistencyLevel consistencyLevel, BiConsumer<? super Result, Throwable> clientCallback)
     {
         super(node, topologies, txnId, sendTo, txn, executeAt, deps, writes, result, fullRoute);
-        Invariants.checkArgument(consistencyLevel == ConsistencyLevel.QUORUM || consistencyLevel == ConsistencyLevel.ALL || consistencyLevel == ConsistencyLevel.SERIAL || consistencyLevel == ConsistencyLevel.ONE);
+        Invariants.requireArgument(consistencyLevel == ConsistencyLevel.QUORUM || consistencyLevel == ConsistencyLevel.ALL || consistencyLevel == ConsistencyLevel.SERIAL || consistencyLevel == ConsistencyLevel.ONE);
         this.consistencyLevel = consistencyLevel;
         registerClientCallback(result, clientCallback);
     }
 
     public void registerClientCallback(Result result, BiConsumer<? super Result, Throwable> clientCallback)
     {
-        Invariants.checkState(callback == null);
+        Invariants.require(callback == null);
         switch (consistencyLevel)
         {
             case ONE: // Can safely upgrade ONE to QUORUM/SERIAL to get a synchronous commit

src/java/org/apache/cassandra/service/accord/interop/AccordInteropReadCallback.java

@@ -60,7 +60,7 @@ public abstract class AccordInteropReadCallback<T> implements Callback<ReadReply
 
     public void onSuccess(Node.Id from, ReadReply reply)
     {
-        Invariants.checkArgument(from.equals(id));
+        Invariants.requireArgument(from.equals(id));
         if (reply.isOk())
         {
             wrapped.onResponse(message.responseWith(convertResponse((ReadOk) reply)).withFrom(endpoint));

src/java/org/apache/cassandra/service/accord/serializers/AcceptSerializers.java

@@ -122,7 +122,7 @@ public class AcceptSerializers
                     }
                     else
                     {
-                        Invariants.checkState(reply == AcceptReply.SUCCESS);
+                        Invariants.require(reply == AcceptReply.SUCCESS);
                         out.writeByte(2);
                     }
                     break;

src/java/org/apache/cassandra/service/accord/serializers/ApplySerializers.java

@@ -45,7 +45,7 @@ public class ApplySerializers
     {
         public void serialize(Apply.Kind kind, DataOutputPlus out, int version) throws IOException
         {
-            Invariants.checkArgument(kind == Apply.Kind.Maximal || kind == Apply.Kind.Minimal);
+            Invariants.requireArgument(kind == Apply.Kind.Maximal || kind == Apply.Kind.Minimal);
             out.writeBoolean(kind == Apply.Kind.Maximal);
         }
 

src/java/org/apache/cassandra/service/accord/serializers/AwaitSerializer.java

@@ -48,7 +48,7 @@ public class AwaitSerializer
             out.writeUnsignedVInt(await.maxAwaitEpoch - await.txnId.epoch());
             out.writeUnsignedVInt(await.maxAwaitEpoch - await.minAwaitEpoch);
             out.writeUnsignedVInt32(await.callbackId + 1);
-            Invariants.checkState(await.callbackId >= -1);
+            Invariants.require(await.callbackId >= -1);
         }
 
         @Override
@@ -62,7 +62,7 @@ public class AwaitSerializer
             long maxAwaitEpoch = in.readUnsignedVInt() + txnId.epoch();
             long minAwaitEpoch = maxAwaitEpoch - in.readUnsignedVInt();
             int callbackId = in.readUnsignedVInt32() - 1;
-            Invariants.checkState(callbackId >= -1);
+            Invariants.require(callbackId >= -1);
             return Await.SerializerSupport.create(txnId, scope, blockedUntil, notifyProgressLog, minAwaitEpoch, maxAwaitEpoch, callbackId);
         }
 

src/java/org/apache/cassandra/service/accord/serializers/CommandSerializers.java

@@ -208,7 +208,7 @@ public class CommandSerializers
             {
                 if ((flags & 1) != 0)
                     return;
-                flags >>= 1;
+                flags >>>= 1;
             }
             in.readUnsignedVInt();
             in.readUnsignedVInt();
@@ -233,14 +233,14 @@ public class CommandSerializers
             out.writeUnsignedVInt32(flags);
             if (executeAt == null)
             {
-                Invariants.checkState(nullable);
+                Invariants.require(nullable);
             }
             else
             {
                 out.writeUnsignedVInt(executeAt.epoch());
                 out.writeUnsignedVInt(executeAt.hlc());
                 out.writeUnsignedVInt32(executeAt.node.id);
-                if ((flags & HAS_UNIQUE_HLC) != 0)
+                if (executeAt.hasDistinctHlcAndUniqueHlc())
                     out.writeUnsignedVInt(executeAt.uniqueHlc() - executeAt.hlc());
             }
         }
@@ -261,13 +261,13 @@ public class CommandSerializers
             long size = TypeSizes.sizeofUnsignedVInt(flags);
             if (executeAt == null)
             {
-                Invariants.checkState(nullable);
+                Invariants.require(nullable);
                 return size;
             }
             size += TypeSizes.sizeofUnsignedVInt(executeAt.epoch());
             size += TypeSizes.sizeofUnsignedVInt(executeAt.hlc());
             size += TypeSizes.sizeofUnsignedVInt(executeAt.node.id);
-            if ((flags & HAS_UNIQUE_HLC) != 0)
+            if (executeAt.hasDistinctHlcAndUniqueHlc())
                 size += TypeSizes.sizeofUnsignedVInt(executeAt.uniqueHlc() - executeAt.hlc());
             return size;
         }
@@ -276,7 +276,7 @@ public class CommandSerializers
         {
             if (executeAt == null)
             {
-                Invariants.checkState(nullable);
+                Invariants.require(nullable);
                 return 1;
             }
 

src/java/org/apache/cassandra/service/accord/serializers/CommandStoreSerializers.java

@@ -138,7 +138,7 @@ public class CommandStoreSerializers
         public void serialize(RedundantBefore.Entry t, DataOutputPlus out, int version) throws IOException
         {
             KeySerializers.range.serialize(t.range, out, version);
-            Invariants.checkState(t.startOwnershipEpoch <= t.endOwnershipEpoch);
+            Invariants.require(t.startOwnershipEpoch <= t.endOwnershipEpoch);
             out.writeUnsignedVInt(t.startOwnershipEpoch);
             if (t.endOwnershipEpoch == Long.MAX_VALUE) out.writeUnsignedVInt(0L);
             else out.writeUnsignedVInt(1 + t.endOwnershipEpoch - t.startOwnershipEpoch);

src/java/org/apache/cassandra/service/accord/serializers/SmallEnumSerializer.java

@@ -39,7 +39,7 @@ public class SmallEnumSerializer<E extends Enum<E>> implements IVersionedSeriali
     public SmallEnumSerializer(Class<E> clazz)
     {
         this.values = clazz.getEnumConstants();
-        Invariants.checkArgument(values.length < 255); // allow an extra 1 for nullable variant to ensure consistency
+        Invariants.requireArgument(values.length < 255); // allow an extra 1 for nullable variant to ensure consistency
     }
 
     public E forOrdinal(int ordinal)

src/java/org/apache/cassandra/service/accord/serializers/WaitingOnSerializer.java

@@ -41,7 +41,7 @@ public class WaitingOnSerializer
 {
     public static void serializeBitSetsOnly(TxnId txnId, WaitingOn waitingOn, DataOutputPlus out) throws IOException
     {
-        Invariants.checkState(txnId.is(Key) == (waitingOn.appliedOrInvalidated == null));
+        Invariants.require(txnId.is(Key) == (waitingOn.appliedOrInvalidated == null));
         int keyCount = waitingOn.keys.size();
         int txnIdCount = waitingOn.txnIdCount();
         int waitingOnLength = (txnIdCount + keyCount + 63) / 64;
@@ -78,8 +78,8 @@ public class WaitingOnSerializer
             RangeDeps directRangeDeps = deps.rangeDeps;
             KeyDeps directKeyDeps = deps.directKeyDeps;
             int txnIdCount = directRangeDeps.txnIdCount() + directKeyDeps.txnIdCount();
-            Invariants.checkState(waitingOn.size()/64 == (txnIdCount + keys.size() + 63) / 64);
+            Invariants.require(waitingOn.size()/64 == (txnIdCount + keys.size() + 63) / 64);
-            Invariants.checkState(appliedOrInvalidated == null || (appliedOrInvalidated.size()/64 == (txnIdCount + 63)/64));
+            Invariants.require(appliedOrInvalidated == null || (appliedOrInvalidated.size()/64 == (txnIdCount + 63)/64));
 
             WaitingOn result = new WaitingOn(keys, directRangeDeps, directKeyDeps, waitingOn, appliedOrInvalidated);
             if (executeAtLeast != null) return new Command.WaitingOnWithExecuteAt(result, executeAtLeast);
@@ -102,7 +102,7 @@ public class WaitingOnSerializer
     private static void serialize(int length, SimpleBitSet write, DataOutputPlus out) throws IOException
     {
         long[] bits = SimpleBitSet.SerializationSupport.getArray(write);
-        Invariants.checkState(length == bits.length);
+        Invariants.require(length == bits.length);
         for (int i = 0; i < length; i++)
             out.writeLong(bits[i]);
     }
@@ -118,7 +118,7 @@ public class WaitingOnSerializer
     public static long serializedSize(int length, SimpleBitSet write)
     {
         long[] bits = SimpleBitSet.SerializationSupport.getArray(write);
-        Invariants.checkState(length == bits.length, "Expected length %d != %d", length, bits.length);
+        Invariants.require(length == bits.length, "Expected length %d != %d", length, bits.length);
         return (long) TypeSizes.LONG_SIZE * length;
     }
 }

src/java/org/apache/cassandra/service/accord/txn/AccordUpdateParameters.java

@@ -26,9 +26,13 @@ import com.google.common.collect.ImmutableMap;
 import org.apache.cassandra.cql3.QueryOptions;
 import org.apache.cassandra.cql3.UpdateParameters;
 import org.apache.cassandra.db.DecoratedKey;
+import org.apache.cassandra.db.marshal.TimeUUIDType;
 import org.apache.cassandra.db.partitions.Partition;
+import org.apache.cassandra.exceptions.InvalidRequestException;
 import org.apache.cassandra.schema.TableMetadata;
 import org.apache.cassandra.service.ClientState;
+import org.apache.cassandra.service.paxos.Ballot;
+import org.apache.cassandra.utils.TimeUUID;
 
 import static com.google.common.base.Preconditions.checkState;
 import static java.util.concurrent.TimeUnit.MICROSECONDS;
@@ -46,6 +50,22 @@ public class AccordUpdateParameters
         this.timestamp = timestamp;
     }
 
+    static class RowUpdateParameters extends UpdateParameters
+    {
+        private long timeUuidNanos;
+
+        public RowUpdateParameters(TableMetadata metadata, ClientState clientState, QueryOptions options, long timestamp, long nowInSec, int ttl, Map<DecoratedKey, Partition> prefetchedRows) throws InvalidRequestException
+        {
+            super(metadata, clientState, options, timestamp, nowInSec, ttl, prefetchedRows);
+        }
+
+        @Override
+        public byte[] nextTimeUUIDAsBytes()
+        {
+            return TimeUUID.toBytes(Ballot.unixMicrosToMsb(timestamp), TimeUUIDType.signedBytesToNativeLong(timeUuidNanos++));
+        }
+    }
+
     public TxnData getData()
     {
         return data;
@@ -60,13 +80,13 @@ public class AccordUpdateParameters
 
         // TODO : How should Accord work with TTL?
         int ttl = metadata.params.defaultTimeToLive;
-        return new UpdateParameters(metadata,
+        return new RowUpdateParameters(metadata,
-                                    disabledGuardrails,
+                                       disabledGuardrails,
-                                    options,
+                                       options,
-                                    timestamp,
+                                       timestamp,
-                                    MICROSECONDS.toSeconds(timestamp),
+                                       MICROSECONDS.toSeconds(timestamp),
-                                    ttl,
+                                       ttl,
-                                    prefetchRow(metadata, dk, rowIndex));
+                                       prefetchRow(metadata, dk, rowIndex));
     }
 
     private Map<DecoratedKey, Partition> prefetchRow(TableMetadata metadata, DecoratedKey dk, int index)

src/java/org/apache/cassandra/service/accord/txn/TxnData.java

@@ -35,7 +35,7 @@ import org.apache.cassandra.utils.Int32Serializer;
 import org.apache.cassandra.utils.NullableSerializer;
 import org.apache.cassandra.utils.ObjectSizes;
 
-import static accord.utils.Invariants.checkArgument;
+import static accord.utils.Invariants.requireArgument;
 import static org.apache.cassandra.service.accord.txn.TxnResult.Kind.txn_data;
 
 /**
@@ -84,7 +84,7 @@ public class TxnData extends Int2ObjectHashMap<TxnDataValue> implements TxnResul
 
     public static int txnDataName(TxnDataNameKind kind, int index)
     {
-        checkArgument(index >= 0 && index <= TXN_DATA_NAME_INDEX_MAX);
+        requireArgument(index >= 0 && index <= TXN_DATA_NAME_INDEX_MAX);
         int kindInt = (int)(((long)kind.value) << TXN_DATA_NAME_INDEX_BITS);
         return kindInt | index;
     }
@@ -121,7 +121,7 @@ public class TxnData extends Int2ObjectHashMap<TxnDataValue> implements TxnResul
 
     public static TxnData newWithExpectedSize(int size)
     {
-        checkArgument(size >= 0, "size can't be negative");
+        requireArgument(size >= 0, "size can't be negative");
         size = Math.max(4, size);
         return new TxnData(size < 1073741824 ? (int)((float)size / 0.75F + 1.0F) : Integer.MAX_VALUE);
     }

src/java/org/apache/cassandra/service/accord/txn/TxnUpdate.java

@@ -53,7 +53,7 @@ import org.apache.cassandra.transport.ProtocolVersion;
 import org.apache.cassandra.utils.ByteBufferUtil;
 import org.apache.cassandra.utils.ObjectSizes;
 
-import static accord.utils.Invariants.checkArgument;
+import static accord.utils.Invariants.requireArgument;
 import static accord.utils.SortedArrays.Search.CEIL;
 import static org.apache.cassandra.service.accord.AccordSerializers.consistencyLevelSerializer;
 import static org.apache.cassandra.service.accord.AccordSerializers.serialize;
@@ -89,7 +89,7 @@ public class TxnUpdate extends AccordUpdate
 
     public TxnUpdate(List<TxnWrite.Fragment> fragments, TxnCondition condition, @Nullable ConsistencyLevel cassandraCommitCL, boolean preserveTimestamps)
     {
-        checkArgument(cassandraCommitCL == null || IAccordService.SUPPORTED_COMMIT_CONSISTENCY_LEVELS.contains(cassandraCommitCL));
+        requireArgument(cassandraCommitCL == null || IAccordService.SUPPORTED_COMMIT_CONSISTENCY_LEVELS.contains(cassandraCommitCL));
         // TODO: Figure out a way to shove keys into TxnCondition, and have it implement slice/merge.
         this.keys = Keys.of(fragments, fragment -> fragment.key);
         fragments.sort(TxnWrite.Fragment::compareKeys);

src/java/org/apache/cassandra/tcm/AtomicLongBackedProcessor.java

@@ -188,7 +188,7 @@ public class AtomicLongBackedProcessor extends AbstractLocalProcessor
                     break;
                 if (current.epoch.isEqualOrBefore(start))
                 {
-                    Invariants.checkState(current.epoch.isDirectlyAfter(metadata.epoch));
+                    Invariants.require(current.epoch.isDirectlyAfter(metadata.epoch));
                     metadata = current.transform.execute(metadata).success().metadata;
                 }
                 else if (current.epoch.isAfter(start))

src/java/org/apache/cassandra/tcm/Processor.java

@@ -132,7 +132,7 @@ public interface Processor
         cms.add(acc);
         for (Entry entry : logState.entries)
         {
-            Invariants.checkState(entry.epoch.isDirectlyAfter(acc.epoch), "%s should have been directly after %s", entry.epoch, acc.epoch);
+            Invariants.require(entry.epoch.isDirectlyAfter(acc.epoch), "%s should have been directly after %s", entry.epoch, acc.epoch);
             Transformation.Result res = entry.transform.execute(acc);
             assert res.isSuccess() : res.toString();
             acc = res.success().metadata;

src/java/org/apache/cassandra/tcm/log/LogReader.java

@@ -161,7 +161,7 @@ public interface LogReader
             }
             else
             {
-                Invariants.checkState(closestSnapshot.epoch.isEqualOrAfter(start),
+                Invariants.require(closestSnapshot.epoch.isEqualOrAfter(start),
                                       "Got %s, but requested snapshot of %s", closestSnapshot.epoch, start);
                 EntryHolder entryHolder = getEntries(closestSnapshot.epoch, end);
                 return new LogState(closestSnapshot, ImmutableList.copyOf(entryHolder.entries));

src/java/org/apache/cassandra/tcm/log/LogState.java

@@ -73,7 +73,7 @@ public class LogState
     // Uses Replication rather than an just a list of entries primarily to avoid duplicating the existing serializer
     public LogState(ClusterMetadata baseState, ImmutableList<Entry> entries)
     {
-        Invariants.checkState(baseState == null ||
+        Invariants.require(baseState == null ||
                               entries.isEmpty() ||
                               entries.get(0).epoch.isDirectlyAfter(baseState.epoch),
                               "Base state: %s, first entry: %s", baseState == null ? null : baseState.epoch, entries.isEmpty() ? null : entries.get(0).epoch);

src/java/org/apache/cassandra/tcm/membership/Directory.java

@@ -300,7 +300,7 @@ public class Directory implements MetadataValue<Directory>
 
     public Directory removed(Epoch removedIn, NodeId id, InetAddressAndPort addr)
     {
-        Invariants.checkState(!peers.containsKey(id));
+        Invariants.require(!peers.containsKey(id));
         return new Directory(nextId,
                              lastModified,
                              peers,

src/java/org/apache/cassandra/utils/MergeIterator.java

@@ -67,7 +67,7 @@ public abstract class MergeIterator<In,Out> extends AbstractIterator<Out> implem
             @Override
             protected E getReduced()
             {
-                Invariants.checkState(first != null);
+                Invariants.require(first != null);
                 return first;
             }
         });

src/java/org/apache/cassandra/utils/btree/BTree.java

@@ -143,8 +143,8 @@ public class BTree
 
     public static Object[] unsafeAllocateNonEmptyLeaf(int size)
     {
-        Invariants.checkArgument(size > 0, "size should be non-zero");
+        Invariants.requireArgument(size > 0, "size should be non-zero");
-        Invariants.checkArgument(size <= MAX_KEYS, "size (%s) should be no more than %s", size, MAX_KEYS);
+        Invariants.requireArgument(size <= MAX_KEYS, "size (%s) should be no more than %s", size, MAX_KEYS);
         return new Object[size | 1];
     }
 

src/java/org/apache/cassandra/utils/concurrent/LockWithAsyncSignal.java

@@ -107,7 +107,7 @@ public class LockWithAsyncSignal implements Lock
     {
         Thread thread = Thread.currentThread();
         int restoreDepth = depth;
-        Invariants.checkState(owner == thread);
+        Invariants.require(owner == thread);
 
         depth = 0;
         owner = null;
@@ -117,7 +117,7 @@ public class LockWithAsyncSignal implements Lock
 
     public void unlock()
     {
-        Invariants.checkState(owner == Thread.currentThread());
+        Invariants.require(owner == Thread.currentThread());
         if (--depth > 0)
             return;
 

test/distributed/org/apache/cassandra/distributed/impl/Coordinator.java

@@ -158,7 +158,7 @@ public class Coordinator implements ICoordinator
                 boundBBValues.add(ByteBufferUtil.objectToBytes(boundValue));
 
             prepared.validate(clientState);
-            Invariants.checkState(prepared instanceof SelectStatement, "Only SELECT statements can be executed with paging %s", prepared);
+            Invariants.require(prepared instanceof SelectStatement, "Only SELECT statements can be executed with paging %s", prepared);
 
             Dispatcher.RequestTime requestTime = Dispatcher.RequestTime.forImmediateExecution();
             SelectStatement selectStatement = (SelectStatement) prepared;

test/distributed/org/apache/cassandra/distributed/test/IntegrationTestBase.java

@@ -44,7 +44,7 @@ public class IntegrationTestBase extends TestBaseImpl
 
     protected static void init(int nodes, Consumer<IInstanceConfig> cfg) throws Throwable
     {
-        Invariants.checkState(!initialized);
+        Invariants.require(!initialized);
         cluster = Cluster.build()
                          .withNodes(nodes)
                          .withConfig(cfg)

test/distributed/org/apache/cassandra/fuzz/topology/TopologyMixupTestBase.java

@@ -530,35 +530,35 @@ public abstract class TopologyMixupTestBase<S extends TopologyMixupTestBase.Sche
 
                 this.yamlConfigOverrides = CONF_GEN.next(rs);
                 cluster = Cluster.build(topologyHistory.minNodes)
-                        .withTokenSupplier(topologyHistory)
+                                 .withTokenSupplier(topologyHistory)
-                        .withConfig(c -> {
+                                 .withConfig(c -> {
-                            c.with(Feature.values())
+                                     c.with(Feature.values())
-                                    .set("write_request_timeout", "10s")
+                                      .set("write_request_timeout", "10s")
-                                    .set("read_request_timeout", "10s")
+                                      .set("read_request_timeout", "10s")
-                                    .set("range_request_timeout", "20s")
+                                      .set("range_request_timeout", "20s")
-                                    .set("request_timeout", "20s")
+                                      .set("request_timeout", "20s")
-                                    .set("transaction_timeout", "15s")
+                                      .set("transaction_timeout", "15s")
-                                    .set("native_transport_timeout", "30s")
+                                      .set("native_transport_timeout", "30s")
-                                    // bound startup to some value larger than the task timeout, this is to allow the
+                                      // bound startup to some value larger than the task timeout, this is to allow the
-                                    // tests to stop blocking when a startup issue is detected.  The main reason for
+                                      // tests to stop blocking when a startup issue is detected.  The main reason for
-                                    // this is that startup blocks forever, waiting for accord and streaming to
+                                      // this is that startup blocks forever, waiting for accord and streaming to
-                                    // complete... but if there are bugs at these layers then the startup will never
+                                      // complete... but if there are bugs at these layers then the startup will never
-                                    // exit, blocking the JVM from giving the needed information (logs/seed) to debug.
+                                      // exit, blocking the JVM from giving the needed information (logs/seed) to debug.
-                                    .set(Constants.KEY_DTEST_STARTUP_TIMEOUT, "4m")
+                                      .set(Constants.KEY_DTEST_STARTUP_TIMEOUT, "4m")
-                                    .set(Constants.KEY_DTEST_API_STARTUP_FAILURE_AS_SHUTDOWN, false);
+                                      .set(Constants.KEY_DTEST_API_STARTUP_FAILURE_AS_SHUTDOWN, false);
-                            //TODO (maintenance): where to put this?  Anything touching ConfigGenBuilder with jvm-dtest needs this...
+                                     //TODO (maintenance): where to put this?  Anything touching ConfigGenBuilder with jvm-dtest needs this...
-                            ((InstanceConfig) c).remove("commitlog_sync_period_in_ms");
+                                     ((InstanceConfig) c).remove("commitlog_sync_period_in_ms");
-                            for (Map.Entry<String, Object> e : yamlConfigOverrides.entrySet())
+                                     for (Map.Entry<String, Object> e : yamlConfigOverrides.entrySet())
-                                c.set(e.getKey(), e.getValue());
+                                         c.set(e.getKey(), e.getValue());
-                            onConfigure(c);
+                                     onConfigure(c);
-                        })
+                                 })
-                        //TODO (maintenance): should TopologyHistory also be a INodeProvisionStrategy.Factory so address information is stored in the Node?
+                                 //TODO (maintenance): should TopologyHistory also be a INodeProvisionStrategy.Factory so address information is stored in the Node?
-                        //TODO (maintenance): AbstractCluster's Map<Integer, NetworkTopology.DcAndRack> nodeIdTopology makes playing with dc/rack annoying, if this becomes an interface then TopologyHistory could own
+                                 //TODO (maintenance): AbstractCluster's Map<Integer, NetworkTopology.DcAndRack> nodeIdTopology makes playing with dc/rack annoying, if this becomes an interface then TopologyHistory could own
-                        .withNodeProvisionStrategy((subnet, portMap) -> new INodeProvisionStrategy.AbstractNodeProvisionStrategy(portMap)
+                                 .withNodeProvisionStrategy((subnet, portMap) -> new INodeProvisionStrategy.AbstractNodeProvisionStrategy(portMap)
-                        {
+                                 {
-                            {
+                                     {
-                                Invariants.checkArgument(subnet == 0, "Unexpected subnet detected: %d", subnet);
+                                         Invariants.requireArgument(subnet == 0, "Unexpected subnet detected: %d", subnet);
-                            }
+                                     }
 
                             private final String ipPrefix = "127.0." + subnet + '.';
 
@@ -982,7 +982,7 @@ public abstract class TopologyMixupTestBase<S extends TopologyMixupTestBase.Sche
         {
             String address = addressAndPort.getAddress().getHostAddress();
             String[] parts = address.split("\\.");
-            Invariants.checkState(parts.length == 4, "Unable to parse address %s", address);
+            Invariants.require(parts.length == 4, "Unable to parse address %s", address);
             return Integer.parseInt(parts[3]);
         }
     }

test/harry/main/org/apache/cassandra/harry/dsl/SingleOperationVisitBuilder.java

@@ -461,7 +461,7 @@ class SingleOperationVisitBuilder implements SingleOperationBuilder
         Relations.Relation[] ckRelations = new Relations.Relation[ckIdxRelations.length];
         for (int i = 0; i < ckRelations.length; i++)
         {
-            Invariants.checkState(ckIdxRelations[i].column < valueGenerators.ckColumnCount());
+            Invariants.require(ckIdxRelations[i].column < valueGenerators.ckColumnCount());
             ckRelations[i] = new Relations.Relation(ckIdxRelations[i].kind,
                                                     valueGenerators.ckGen().descriptorAt(ckIdxRelations[i].idx),
                                                     ckIdxRelations[i].column);
@@ -470,7 +470,7 @@ class SingleOperationVisitBuilder implements SingleOperationBuilder
         Relations.Relation[] regularRelations = new Relations.Relation[regularIdxRelations.length];
         for (int i = 0; i < regularRelations.length; i++)
         {
-            Invariants.checkState(regularIdxRelations[i].column < valueGenerators.regularColumnCount());
+            Invariants.require(regularIdxRelations[i].column < valueGenerators.regularColumnCount());
             regularRelations[i] = new Relations.Relation(regularIdxRelations[i].kind,
                                                          valueGenerators.regularColumnGen(regularIdxRelations[i].column).descriptorAt(regularIdxRelations[i].idx),
                                                          regularIdxRelations[i].column);
@@ -479,7 +479,7 @@ class SingleOperationVisitBuilder implements SingleOperationBuilder
         Relations.Relation[] staticRelations = new Relations.Relation[staticIdxRelations.length];
         for (int i = 0; i < staticRelations.length; i++)
         {
-            Invariants.checkState(staticIdxRelations[i].column < valueGenerators.staticColumnCount());
+            Invariants.require(staticIdxRelations[i].column < valueGenerators.staticColumnCount());
             staticRelations[i] = new Relations.Relation(staticIdxRelations[i].kind,
                                                         valueGenerators.staticColumnGen(staticIdxRelations[i].column).descriptorAt(staticIdxRelations[i].idx),
                                                         staticIdxRelations[i].column);

test/harry/main/org/apache/cassandra/harry/execution/CQLTesterVisitExecutor.java

@@ -54,7 +54,7 @@ public class CQLTesterVisitExecutor extends CQLVisitExecutor
     {
         List<ResultSetRow> actual = new ArrayList<>();
         // TODO: Have never tested with multiple
-        Invariants.checkState(visit.operations.length == 1);
+        Invariants.require(visit.operations.length == 1);
         for (UntypedResultSet.Row row : execute.apply(statement))
             actual.add(resultSetToRow(schema, (Operations.SelectStatement) visit.operations[0], row));
         return actual;
@@ -99,7 +99,7 @@ public class CQLTesterVisitExecutor extends CQLVisitExecutor
                 {
                     for (int j = 0; j < schema.clusteringKeys.size(); j++)
                     {
-                        Invariants.checkState(!row.has(schema.clusteringKeys.get(j).name),
+                        Invariants.require(!row.has(schema.clusteringKeys.get(j).name),
                                               "All elements of clustering key should have been null");
                     }
                     clusteringKey = NIL_KEY;

test/harry/main/org/apache/cassandra/harry/execution/CQLVisitExecutor.java

@@ -139,7 +139,7 @@ public abstract class CQLVisitExecutor
         // All operations are not touching any data
         if (compiledStatement == null)
         {
-            Invariants.checkArgument(Arrays.stream(visit.operations).allMatch(op -> op.kind() == Operations.Kind.CUSTOM));
+            Invariants.requireArgument(Arrays.stream(visit.operations).allMatch(op -> op.kind() == Operations.Kind.CUSTOM));
             return;
         }
 
@@ -150,7 +150,7 @@ public abstract class CQLVisitExecutor
         }
         else
         {
-            Invariants.checkState(selects.size() == 1);
+            Invariants.require(selects.size() == 1);
             executeValidatingVisit(visit, selects, compiledStatement);
         }
         dataTracker.end(visit);

test/harry/main/org/apache/cassandra/harry/execution/DataTracker.java

@@ -69,7 +69,7 @@ public interface DataTracker
         public void begin(Visit visit)
         {
             long prev = started.get();
-            Invariants.checkState(prev == 0 || visit.lts == (prev + 1));
+            Invariants.require(prev == 0 || visit.lts == (prev + 1));
             started.set(visit.lts);
             for (int i = 0; i < visit.operations.length; i++)
             {
@@ -88,7 +88,7 @@ public interface DataTracker
         public void end(Visit visit)
         {
             long current = started.get();
-            Invariants.checkState(current == visit.lts, "Current stated %d, current visit: %d", current, visit.lts);
+            Invariants.require(current == visit.lts, "Current stated %d, current visit: %d", current, visit.lts);
             finished.set(visit.lts);
         }
 

test/harry/main/org/apache/cassandra/harry/execution/InJvmDTestVisitExecutor.java

@@ -103,7 +103,7 @@ public class InJvmDTestVisitExecutor extends CQLVisitExecutor
 
     protected List<ResultSetRow> executeWithResult(Visit visit, int node, int pageSize, CompiledStatement statement, ConsistencyLevel consistencyLevel)
     {
-        Invariants.checkState(visit.operations.length == 1);
+        Invariants.require(visit.operations.length == 1);
         Object[][] rows;
         if (consistencyLevel == ConsistencyLevel.NODE_LOCAL)
             rows = cluster.get(node).executeInternal(statement.cql(), statement.bindings());
@@ -199,7 +199,7 @@ public class InJvmDTestVisitExecutor extends CQLVisitExecutor
                 {
                     for (int j = 0; j < schema.clusteringKeys.size(); j++)
                     {
-                        Invariants.checkState(result[selection.indexOf(schema.clusteringKeys.get(j))] == null,
+                        Invariants.require(result[selection.indexOf(schema.clusteringKeys.get(j))] == null,
                                               "All elements of clustering key should have been null");
                     }
                     clusteringKey = NIL_KEY;

test/harry/main/org/apache/cassandra/harry/execution/QueryBuildingVisitExecutor.java

@@ -72,7 +72,7 @@ public class QueryBuildingVisitExecutor extends VisitExecutor
             return query;
         }
 
-        Invariants.checkState(bindings.isEmpty() && visitedPds.isEmpty() && selects.isEmpty());
+        Invariants.require(bindings.isEmpty() && visitedPds.isEmpty() && selects.isEmpty());
         return null;
     }
 
@@ -107,7 +107,7 @@ public class QueryBuildingVisitExecutor extends VisitExecutor
     {
         if (statements.isEmpty())
         {
-            Invariants.checkState(bindings.isEmpty() && visitedPds.isEmpty() && selects.isEmpty());
+            Invariants.require(bindings.isEmpty() && visitedPds.isEmpty() && selects.isEmpty());
             return;
         }
 

test/harry/main/org/apache/cassandra/harry/execution/RingAwareInJvmDTestVisitExecutor.java

@@ -119,7 +119,7 @@ public class RingAwareInJvmDTestVisitExecutor extends InJvmDTestVisitExecutor
     {
         try
         {
-            Invariants.checkState(visit.visitedPartitions.size() == 1,
+            Invariants.require(visit.visitedPartitions.size() == 1,
                                   "Ring aware executor can only read and write one partition at a time");
             for (TokenPlacementModel.Replica replica : getReplicasFor(visit.visitedPartitions.iterator().next().longValue()))
             {

test/harry/main/org/apache/cassandra/harry/gen/Generators.java

@@ -282,7 +282,7 @@ public class Generators
             {
                 T v = delegate.generate(rng);
                 int hashCode = v.hashCode();
-                Invariants.checkState(hashCode != System.identityHashCode(v), "hashCode was not overridden for type %s", v.getClass());
+                Invariants.require(hashCode != System.identityHashCode(v), "hashCode was not overridden for type %s", v.getClass());
                 if (hashCodes.contains(hashCode))
                     continue;
                 hashCodes.add(hashCode);

test/harry/main/org/apache/cassandra/harry/gen/InvertibleGenerator.java

@@ -74,9 +74,9 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
                                Generator<T> gen,
                                Comparator<T> comparator)
     {
-        Invariants.checkState(population > 0,
+        Invariants.require(population > 0,
                               "Population should be strictly positive %d", population);
-        Invariants.checkState(Long.compareUnsigned(typeEntropy, 0) > 0,
+        Invariants.require(Long.compareUnsigned(typeEntropy, 0) > 0,
                               "Type entropy should be strictly positive, but was %d: %s", typeEntropy, gen);
 
         // We can / will generate at most that many values
@@ -101,7 +101,7 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
 
             Object inflated = inflate(candidate);
             int hash = ArrayUtils.hashCode(inflated);
-            Invariants.checkState(hash  != System.identityHashCode(inflated), "hashCode was not overridden for type %s", inflated.getClass());
+            Invariants.require(hash  != System.identityHashCode(inflated), "hashCode was not overridden for type %s", inflated.getClass());
 
             if (hashes.add(hash))
                 allocatedDescriptors.add(candidate);
@@ -117,7 +117,7 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
             for (int i = 1; i < allocatedDescriptors.size(); i++)
             {
                 T current = inflate(allocatedDescriptors.get(i));
-                Invariants.checkState( comparator.compare(current, prev) > 0,
+                Invariants.require( comparator.compare(current, prev) > 0,
                                        () -> String.format("%s should be strictly after %s", prev, current));
             }
         }
@@ -138,7 +138,7 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
     @Override
     public T inflate(long descriptor)
     {
-        Invariants.checkState(!MagicConstants.MAGIC_DESCRIPTOR_VALS.contains(descriptor),
+        Invariants.require(!MagicConstants.MAGIC_DESCRIPTOR_VALS.contains(descriptor),
                               String.format("Should not be able to inflate %d, as it's magic value", descriptor));
         return SeedableEntropySource.computeWithSeed(descriptor, gen::generate);
     }
@@ -158,13 +158,13 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
                     {
                         Object[] valueArr = (Object[]) value;
                         Object[] expectedArr = (Object[]) expected;
-                        Invariants.checkState(comparator.compare((T) expected, value) != 0,
+                        Invariants.require(comparator.compare((T) expected, value) != 0,
                                               "%s was found: %s", Arrays.toString(expectedArr), Arrays.toString(valueArr));
 
                     }
                     else
                     {
-                        Invariants.checkState(comparator.compare((T) expected, value) != 0,
+                        Invariants.require(comparator.compare((T) expected, value) != 0,
                                               "%s was found: %s", expected, value);
                     }
 
@@ -179,13 +179,13 @@ public class InvertibleGenerator<T> implements HistoryBuilder.IndexedBijection<T
                     Object[] valueArr = (Object[]) value;
                     Object[] expectedArr = (Object[]) expected;
 
-                    Invariants.checkState(comparator.compare((T) expected, value) == 0,
+                    Invariants.require(comparator.compare((T) expected, value) == 0,
                                           "%s != %s", Arrays.toString(expectedArr), Arrays.toString(valueArr));
 
                 }
                 else
                 {
-                    Invariants.checkState(comparator.compare((T) expected, value) == 0,
+                    Invariants.require(comparator.compare((T) expected, value) == 0,
                                           "%s != %s", expected, value);
                 }
 

test/harry/main/org/apache/cassandra/harry/model/QuiescentChecker.java

@@ -191,7 +191,7 @@ public class QuiescentChecker implements Model
 
     public static boolean vdsEqual(long[] expected, long[] actual)
     {
-        Invariants.checkState(expected.length == actual.length);
+        Invariants.require(expected.length == actual.length);
         for (int i = 0; i < actual.length; i++)
         {
             long expectedD = expected[i];

test/harry/main/org/apache/cassandra/harry/op/Operations.java

@@ -471,7 +471,7 @@ public class Operations
             }
             else
             {
-                Invariants.checkState(schema.allColumnInSelectOrder.size() == bitSet.size());
+                Invariants.require(schema.allColumnInSelectOrder.size() == bitSet.size());
                 Map<ColumnSpec<?>, Integer> columns = new HashMap<>();
                 for (int i = 0; i < schema.allColumnInSelectOrder.size(); i++)
                 {

test/harry/main/org/apache/cassandra/harry/test/SimpleBijectionTest.java

@@ -52,7 +52,7 @@ public class SimpleBijectionTest
                         Object next = generator.inflate(generator.descriptorAt(i));
                         if (previous != null)
                         {
-                            Invariants.checkState(column.type.comparator().compare(next, previous) > 0,
+                            Invariants.require(column.type.comparator().compare(next, previous) > 0,
                                                   "%s should be > %s", next, previous);
                         }
                         previous = next;

test/simulator/main/org/apache/cassandra/simulator/logging/RunStartDefiner.java

@@ -26,7 +26,7 @@ public class RunStartDefiner extends PropertyDefinerBase
 {
     static
     {
-        Invariants.checkState(CassandraRelevantProperties.SIMULATOR_STARTED.getString() != null);
+        Invariants.require(CassandraRelevantProperties.SIMULATOR_STARTED.getString() != null);
     }
 
     @Override

test/simulator/test/org/apache/cassandra/simulator/test/HarrySimulatorTest.java

@@ -757,7 +757,7 @@ public class HarrySimulatorTest
 
             Visit visit = new Visit(lts, new Operations.Operation[]{ simulation.insertGen.generate(simulation.rng).toOp(lts) });
             Visit prev_ = simulation.log.put(lts, visit);
-            Invariants.checkState(prev_ == null);
+            Invariants.require(prev_ == null);
 
             actions[i] = new Actions.LambdaAction("", Action.Modifiers.RELIABLE_NO_TIMEOUTS, () -> {
                 CompiledStatement compiledStatement = simulation.queryBuilder.compile(visit);

test/simulator/test/org/apache/cassandra/simulator/test/HarryValidatingQuery.java

@@ -79,8 +79,8 @@ public class HarryValidatingQuery extends SimulatedAction
                 try
                 {
                     TokenPlacementModel.ReplicatedRanges ring = rf.replicate(owernship);
-                    Invariants.checkState(visit.operations.length == 1);
+                    Invariants.require(visit.operations.length == 1);
-                    Invariants.checkState(visit.operations[0] instanceof Operations.SelectStatement);
+                    Invariants.require(visit.operations[0] instanceof Operations.SelectStatement);
                     Operations.SelectStatement select = (Operations.SelectStatement) visit.operations[0];
                     for (TokenPlacementModel.Replica replica : ring.replicasFor(token(select.pd)))
                     {

test/unit/org/apache/cassandra/concurrent/ManualExecutor.java

@@ -110,7 +110,7 @@ public class ManualExecutor implements ExecutorPlus
 
         Task(Runnable runnable, Callable<?> callable, WithResources withResources, Object result, FutureImpl<?> future)
         {
-            Invariants.checkArgument(runnable != null ^ callable != null);
+            Invariants.requireArgument(runnable != null ^ callable != null);
 
             this.runnable = runnable;
             this.callable = callable;

test/unit/org/apache/cassandra/cql3/ast/Visitor.java

@@ -92,7 +92,7 @@ public interface Visitor
 
         public static CompositeVisitor of(List<Visitor> visitors)
         {
-            Invariants.checkArgument(!visitors.isEmpty(), "Visitors may not be empty");
+            Invariants.requireArgument(!visitors.isEmpty(), "Visitors may not be empty");
 
             if (Stream.of(visitors).noneMatch(v -> v instanceof CompositeVisitor))
                 return new CompositeVisitor(visitors);

test/unit/org/apache/cassandra/journal/IndexTest.java

@@ -218,7 +218,7 @@ public class IndexTest
             for (long i : value)
                 inMemory.update(key, Index.readOffset(i), Index.readSize(i));
             for (int i = 1 ; i < value.length ; ++i)
-                Invariants.checkState(value[i - 1] > value[i]);
+                Invariants.require(value[i - 1] > value[i]);
         }
         assertIndex(map, inMemory);
 

test/unit/org/apache/cassandra/service/accord/EpochSyncTest.java

@@ -336,7 +336,7 @@ public class EpochSyncTest
             if (cms.metadata().inProgressSequences.isEmpty())
                 throw new IllegalStateException("Attempted to bump epoch when nothing was pending");
             Iterator<MultiStepOperation<?>> it = cms.metadata().inProgressSequences.iterator();
-            Invariants.checkState(it.hasNext());
+            Invariants.require(it.hasNext());
             notify(process(it.next()).metadata);
         }
 
@@ -562,8 +562,8 @@ public class EpochSyncTest
 
         void registerNode(Node.Id id, long token)
         {
-            Invariants.checkState(!tokens.contains(token), "Attempted to add token %d for node %s but token is already taken", token, id);
+            Invariants.require(!tokens.contains(token), "Attempted to add token %d for node %s but token is already taken", token, id);
-            Invariants.checkState(!instances.containsKey(id), "Attempted to add node %s; but already exists", id);
+            Invariants.require(!instances.containsKey(id), "Attempted to add node %s; but already exists", id);
 
             ClusterMetadata.Transformer builder = cms.metadata().transformer();
 
@@ -598,7 +598,7 @@ public class EpochSyncTest
         void removeNode(Node.Id pick)
         {
             Instance inst = Objects.requireNonNull(instances.get(pick), "Unknown id " + pick);
-            Invariants.checkState(!removed.contains(pick), "Can not remove node twice; node " + pick);
+            Invariants.require(!removed.contains(pick), "Can not remove node twice; node " + pick);
             removed.add(pick);
             inst.status = Status.Leaving;
             PrepareLeave prepareLeave = new PrepareLeave(new NodeId(pick.id), false, new UniformRangePlacement(), LeaveStreams.Kind.REMOVENODE);
@@ -747,19 +747,19 @@ public class EpochSyncTest
                 switch (status)
                 {
                     case Init:
-                        Invariants.checkState(!t.nodes().contains(id), "Node was in Init state but present in the Topology!");
+                        Invariants.require(!t.nodes().contains(id), "Node was in Init state but present in the Topology!");
-                        Invariants.checkState(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
+                        Invariants.require(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
                         start();
                         status = Status.Registered;
                         break;
                     case Registered:
-                        Invariants.checkState(!t.nodes().contains(id), "Node was in Init state but present in the Topology!");
+                        Invariants.require(!t.nodes().contains(id), "Node was in Init state but present in the Topology!");
-                        Invariants.checkState(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
+                        Invariants.require(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
                         if (current.placements.get(replication_params).writes.byEndpoint().keySet().contains(address(id)))
                             status = Status.Joining;
                         break;
                     case Joining:
-                        Invariants.checkState(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
+                        Invariants.require(current.directory.peerId(address(id)) != null, "Node exists but not in TCM");
                         if (joined(current, id))
                             status = Status.Joined;
                     case Removed:

test/unit/org/apache/cassandra/service/accord/MockDiskStateManager.java

@@ -87,7 +87,7 @@ public enum MockDiskStateManager implements AccordConfigurationService.DiskState
     {
         if (diskState.isEmpty())
             return AccordKeyspace.EpochDiskState.create(epoch);
-        Invariants.checkArgument(epoch >= diskState.minEpoch, "Epoch %d < %d (min)", epoch, diskState.minEpoch);
+        Invariants.requireArgument(epoch >= diskState.minEpoch, "Epoch %d < %d (min)", epoch, diskState.minEpoch);
         if (epoch > diskState.maxEpoch)
             diskState = diskState.withNewMaxEpoch(epoch);
         return diskState;

test/unit/org/apache/cassandra/service/accord/SimulatedAccordCommandStoreTestBase.java

@@ -351,7 +351,7 @@ public abstract class SimulatedAccordCommandStoreTestBase extends CQLTester
     protected static Gen<Pair<Txn, FullRoute<?>>> randomTxn(Gen<Routable.Domain> domainGen, Gen.LongGen tokenGen)
     {
         TableMetadata tbl = reverseTokenTbl;
-        Invariants.checkArgument(tbl.partitioner == Murmur3Partitioner.instance, "Only murmur partitioner is supported; given %s", tbl.partitioner.getClass());
+        Invariants.requireArgument(tbl.partitioner == Murmur3Partitioner.instance, "Only murmur partitioner is supported; given %s", tbl.partitioner.getClass());
         Gen<PartitionKey> keyGen = rs -> new PartitionKey(tbl.id, tbl.partitioner.decorateKey(Murmur3Partitioner.LongToken.keyForToken(tokenGen.nextLong(rs))));
         Gen<Range> rangeGen = rs -> {
             long a = tokenGen.nextLong(rs);

test/unit/org/apache/cassandra/utils/SimulatedMiniCluster.java

@@ -253,7 +253,7 @@ public class SimulatedMiniCluster
         if (current.inProgressSequences.isEmpty())
             throw new IllegalStateException("Attempted to bump epoch when nothing was pending");
         Iterator<MultiStepOperation<?>> it = current.inProgressSequences.iterator();
-        Invariants.checkState(it.hasNext());
+        Invariants.require(it.hasNext());
         notifyMetadataChange(process(it.next()).metadata);
     }