Merge branch 'cassandra-4.0' into cassandra-4.1

CHANGES.txt

@@ -5,6 +5,7 @@
  * Equality check for Paxos.Electorate should not depend on collection types (CASSANDRA-19935)
  * Fix race condition in DecayingEstimatedHistogramReservoir during rescale (CASSANDRA-19365)
 Merged from 4.0:
+ * Allow hint delivery during schema mismatch (CASSANDRA-20188)
  * IndexOutOfBoundsException when accessing partition where the column was deleted (CASSANDRA-20108)
  * Enhance CQLSSTableWriter to notify clients on sstable production (CASSANDRA-19800)
  * Fix gossip issue with gossip-only and bootstrapping nodes missing DC/Rack/Host ID endpoint state (CASSANDRA-19983)

src/java/org/apache/cassandra/hints/HintsDispatchTrigger.java

@@ -19,17 +19,13 @@ package org.apache.cassandra.hints;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import org.apache.cassandra.gms.Gossiper;
-import org.apache.cassandra.schema.Schema;
-
 /**
  * A simple dispatch trigger that's being run every 10 seconds.
  *
  * Goes through all hint stores and schedules for dispatch all the hints for hosts that are:
  * 1. Not currently scheduled for dispatch, and
  * 2. Either have some hint files, or an active hint writer, and
- * 3. Are live, and
- * 4. Have matching schema versions
+ * 3. Are live
  *
  * What does triggering a hints store for dispatch mean?
  * - If there are existing hint files, it means submitting them for dispatch;
@@ -62,7 +58,6 @@ final class HintsDispatchTrigger implements Runnable
                .filter(store -> !isScheduled(store))
                .filter(HintsStore::isLive)
                .filter(store -> store.isWriting() || store.hasFiles())
-               .filter(store -> Schema.instance.isSameVersion(Gossiper.instance.getSchemaVersion(store.address())))
                .forEach(this::schedule);
     }