Converting collections or UDTs to raw bytes is nonsensical - it
allows reading raw serialized bytes which have no meaningful
interpretation.
patch by Mikołaj Diakowski; reviewed by Stefan Miklosovic, Brandon Williams for CASSANDRA-20982
- DurabilityQueue/ShardScheduler deadlock
- MemtableCleanerThread.Cleanup assumes Boolean parameter is non-null, which is invalid if an exception has been thrown
- AccordDurableOnFlush may be invoked while Accord is starting up, so should use AccordService.unsafeInstance
- AccordCache shrink without lock regression
- Cleanup system_accord compaction leftovers before starting up
- system_accord_debug.txn order
- system_accord_debug.txn_blocked_by order
- system_accord_debug.shard_epochs order
Improve:
- Set DefaultProgressLog.setMode(Catchup) during Catchup
- IdentityAccumulators only need to readLast, not readAll
- Limit number of static segments we compact at once to sstable
- If too many static segments on startup, wait for them to be compacted
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-21053
Also Fix:
- Restore MaxDecidedRX on replay
- When catchup_on_start_exit_on_failure == false, should startup on any kind of failure, not only timeout
- lazy vtable LIMIT clause regression
- DurabilityService.onEpochRetired
- Command.validate when uniqueHlc differs
- Avoid unsafe publication of AccordExecutor to scheduledFastTasks
- AccordCache hitRate metric names
- use long for return type of DurationSpec.toNanoseconds
- Repair without all replicas should not request all Accord replicas participate
- ExecuteAtSerializer
- SyncPoints should be coordinated in an epoch that contains the ranges
Also Improve:
- Split Accord startup into local+distributed, ensure we
- Add logging to FetchDurableBefore on startup
- Add randomised testing of AbstractLazyVirtualTable
- Add validation of lazy virtual table key ordering
- Don't send requests to faulty replicas
- shrinkOrEvict large objects without holding lock
- Accord dtest shutdown
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-21042
* Better handling of DOWN unupgraded nodes
* Test that aborted CMS initialization cleans up state properly
* Clean up orphaned PreInitialize entries in the log on bounce
* Unconditionally reset initiator during abort
* Ensure that metadata log entries aren't exchanged before CMS
initialization is complete
* Precalculate common serialization version, excluding non-upgraded and
LEFT nodes
* Decide if metadata-impacting upgrade is in progress using min common
version
* Add metadata identifier to nodetool cms output
Patch by Sam Tunnicliffe and Marcus Eriksson; reviewed by Sam
Tunnicliffe and Marcus Eriksson for CASSANDRA-21036
Co-authored-by: Marcus Eriksson <marcuse@apache.org>
Co-authored-by: Sam Tunnicliffe <samt@apache.org>
For GC like ShenandoahGC/ZGC etc., there are GC events that do not have STW pauses (Concurrent phases).
Operator might find it reasonable to use lower thresholds for events require STW pauses and higher thresholds for concurrent phases.
gc_concurrent_phase_log_threshold and gc_concurrent_phase_warn_threshold configuration options are introduced in cassandra.yaml
Patch by Yuqi Yan; reviewed by Dmitry Konstantinov, Stefan Miklosovic for CASSANDRA-20980
Co-authored-by: Stefan Miklosovic
- Estimate memory required to allocate for applying a partition update into a memtable and allocate this memory in one shot, then use it as a request-local SLAB
- Reduce contention by switching MemtableAllocator.SubAllocator#owns from updates via AtomicLongFieldUpdater to LongAdder usage. MemtableAllocator.SubAllocator#acquired(..) method updates "owns" value but does not use the updated result.
- Reduce contention by replacing of CAS loop in MemtablePool.SubPool#tryAllocate with allocatedUpdater.addAndGet(this, size)
Patch by Dmitry Konstantinov; reviewed by Michael Semb Wever for CASSANDRA-20226
Before the fix during a capacity extension BufferPoolAllocator returned to BufferPool a sliced ByteBuffer wrapper object instead of the originally allocated one, so the ByteBuffer was not recycled by BufferPool
Adjust BufferPoolAllocatorTest to test the ByteBuf capacity extension with a real BufferPool behavior
Patch by Dmitry Konstantinov; reviewed by Michael Semb Wever for CASSANDRA-20753
Also Introduce:
- Sharded/LogLinearDecayingHistogram
Also Improve:
- Do not take a reference to CFK unless relevant
Also Fix:
- Sharded/LogLinearHistogram
- ExecuteFlags serialization bug in ReadData
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-21017
- All retries are appended to a delay queue so overlaps can be pruned
- Quorum successes are not retried if there are superseding sync points covering the ranges
- User-initiated requests are not purged unless the request has timed out or otherwise completed
- Overlapping requests are queued up against the next to run
Alsp (C*):
- Catch-up with quorums on restart
- Manage an ordered set of keys in cache for faster range searches
Also (Accord):
- Update copy of BTree and import IntervalBTree
- Fix RedundantStatus WAS_OWNED_OVERRIDE_MASK
- Add Catchup mechanism to reach parity with a quorum on restart
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-21013
CASSANDRA-20389 implemented limit on table name length of 222
characters. This commit updates the documentation to reflect this.
It also adds an assert in CreateTableValidationTest to ensure that the
documented limit matches the actual constant.
patch by Ruslan Fomkin; reviewed by Brad Schoening, Dmitry Konstantinov for CASSANDRA-20914
Merge ConfigurationService with TopologyManager to remove cyclic dependency and duplicated work.
Also:
- Improve visibility of work blocking topology processing
- Ensure we cannot double-count peers when deciding an epoch's distributed readiness
- Remove the possibility of distributed stalls, by processing new topologies as soon as a
contiguous sequence is known locally, regardless of whether anyprior local epoch is ready to
coordinate or has recorded this fact to peers. The notification of local readiness continues
to be processed only once all prior epochs are ready, but we can begin using and readying
later epochs immediately.
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20998
Also fix:
- Paxos should not update minHlc if AccordService is not setup
- Remove EndpointMapper methods that require non-null, to ensure call-sites handle null case explicitly
- AccordRepair should specify the Node Ids that must participate, but these should not affect the durability requirements for GC
- Avoid erroneously marking UniversalOrInvalidated when only known to quorum
- AccordSyncPropagator should not consult FailureDetector as it may throw UnknownEndpointException
- Refuse ReplaceSameAddress if accord enabled
- Reset Accord topologies on restart if no local command stores to ensure we can catch up (as intervening epochs may have otherwise been GC'd)
- MaybeRecover should not abort if found durable if either: 1) prevProgressToken already witnessed durable; or 2) Home state has requested we recover anyway
- Invariant in MaybeRecover is too strong now we permit recovering when known to be stable
- ReadData must respond with InsufficientAndWaiting if not Stable to ensure Durability is inferred correctly by ExecuteTxn
- Avoid StackOverflowException in NotifyWaitingOn
- PreAccept should honour the REJECTED flag of any member of the latest topology if the vote would be relied upon for any prior epoch's quorum
- Resume Accord bootstrap on restart
- Fix burn test non-determinism
- Reset Accord topologies on restart if no local command stores to ensure we can catch up (as intervening epochs may have otherwise been GC'd)
- Exclude stale or removed ids from sync points
- Terminate a failed DurabilityRequest if a required participant is now removed/hardRemoved
Also improve:
- Introduce accord_debug_keyspace.{listeners_txn, listeners_local}
- Filter and record faulty in AbstractCoordination
- If we are the home shard, and our home progress status is done, we should not wait for the home shard to advance the waiting progress state
- Introduce CommandStore.tryExecuteListening to try to execute all waiting transactions and their dependencies
- ExecuteTxn on recovery should not wait, to avoid consuming progress log concurrency slots for transactions that cannot execute
- HomeState should update its phase based on the command status to handle operator request to retry all states
- Separate home/wait queue in DefaultProgressLog
- Additional tracing
- Do not call trySendMore from prerecordFailure
- Force full recovery for sync points if we have lost quorum
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20921
- Introduce pattern tracing, that can intercept failed or new coordinations matching various filters
- Support additional tracing event collection modes (SAMPLE and RING)
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20911
Also Improve:
- Searchable system_accord_debug.txn
- Integrate txn_blocked_by deadline and depth filter with execution logic, to ensure we terminate promptly and get a best effort reply
patch by Benedict; reviewed by Aleksey Yeschenko for CASSANDRA-20899
To support recovering a node that has lost some of its local transaction log, introduce rebootstrap and unsafe bootstrap modes, where Accord ensures no responses are produced for transactions the node cannot be certain it had not previously answered.
patch by Benedict and Alex Petrov for CASSANDRA-20908
* cassandra-5.0:
ninja-fix – Fix eclipse-warnings error for CASSANDRA-19564
ReadCommandController should close fast to avoid deadlock when building secondary index
* cassandra-4.1:
ninja-fix – Fix eclipse-warnings error for CASSANDRA-19564
ReadCommandController should close fast to avoid deadlock when building secondary index
Codahale metrics do not provide the ability to create custom metric implementations, so we have to inherit from Codahale classes.
For better cache locality rate and counter values are extracted to a common thread-local arrays.
Threads death is tracked using 2 approaches: FastThreadLocal.onRemoval callback and phantom references to Thread objects.
Phantom references are used to track aliveness of metric users and reusing of metric IDs.
Patch by Dmitry Konstantinov; reviewed by Benedict Elliott Smith for CASSANDRA-20250
The patch for 5.0 is preserving old behavior, it is possible to turn on JSON representation by a system property.
The patch for trunk is by default transforming collections to JSON string but there is the property (same as in 5.0) which has default to be set to true.
patch by Marko Tsymbaluk; reviewed by Paulo Motta, Stefan Miklosovic for CASSANDRA-20827
Co-authored-by: Stefan Miklosovic <smiklosovic@apache.org>
The length of table names was not controlled. This is likely due to
confusion between validation methods with similar names. As result
creating tables with too long names led to the too long file name
exceptions during table creations.
This commit adds a validation of table name lengths to avoid the too
long file name errors. The validation length is based on how the table
name is used to create file/directory names, and needs to be exact to
prevent the too long file name exception, but allow all other table
names, which didn't lead to the too long file name exception. This
length limit is different from the existing name length limit of 48
characters used by common validation functions.
Thus, this commit moves out the length validation from the validation
methods into a separate length validation method, so the errors on
names are more specific. The non-length validation methods combined
into a single method, which checks for empty names and valid characters.
New constants are added for the length limits.
Table name related code are moved into methods in TableMetadata class,
so their semantics are more clear and to allow reuse, e.g., in
asserting the table name length constant.
Tests are added for the long table names and non-alphanumeric names.
Keyspace name validation function is now shared between two classes and
a unit test of it is added.
Patch by Ruslan Fomkin; reviewed by Piotr Kołaczkowski, Dmitry
Konstantinov, Maxwell Guo for CASSANDRA-20389
patch by Caleb Rackliffe; reviewed by Marcus Eriksson for CASSANDRA-20887
Co-authored-by: Caleb Rackliffe <calebrackliffe@gmail.com>
Co-authored-by: Marcus Eriksson <marcuse@apache.org>
Also Fix:
- RegisteredCallback should remove itself from callback map when cancelled
- Do not throw CancellationException when processing requests that have been aborted, as may be caused by a successful meaningful reply that can be overridden
- system_accord_debug.{executors,coordinations} fail with ClassCastException
- CommandStore.updateMinHlc eats up CPU as called much too often
- AccordCache not notifying flushed on shutdown
Also Improve:
- Support skipping Deps
- Violation information reported
- Sort CommandStore shards by id
patch by Benedict; reviewed by Aleksey Yeschenko for CASSANDRA-20896
Also Fix:
- JournalAndTableKeyIterator not merging in consistent order, which can lead to replaying topologies in non-ascending order
- Invariant failure when reporting topologies if fetchTopologies on startup yields a gap
- removeRedundantMissing could erroneously remove missing dependencies occurring after the new appliedBeforeIndex
- Invariant failure for some propagate calls supplying 'wrong' addRoute
- Disambiguate nextTxnId and nextTxnIdWithDefaultFlags
Also Improve:
- LocalLog should not use NoSuchElementException for control flow (instead use ConcurrentSkipListMap)
patch by Benedict; reviewed by Aleksey Yeschenko for CASSANDRA-20886
- JournalAndTableKeyIterator not merging in consistent order
- Track all active Coordinations
- Refactor Replica/Coordinator metrics and report Coordinator exhausted/preempted/timeout
- DurabilityQueue metrics and visibility
Also Fix:
- WaitingState can get cause distributed stall when asked to wait for CanApply if not yet PreCommitted; track separate querying state and advance this to the next achievable state rather than the desired final state
- Stalled coordinators should not prevent recovery
- Edge case with fetch unable to make progress when pre-bootstrap and all peers have GC'd
- Dependency initialisation for sync points across certain ownership changes
- SyncPoint propagation may not include all of the epochs required on the receiving node for ranges they have lost but not closed, and receiving node does not validate them
- Stable tracker accounting with LocalExecute
- Do not prune non-durable APPLIED as must be reported in dependencies until durably applied (so as not to break recovery)
- Ensure we cannot race with replies when initiating Coordination
- ProgressLog does not guarantee to clear home or waiting states when erased or invalidated by compaction
- WaitingState on non-home shard cannot guarantee progress once home shard is Erased
- WaitingOnSync handles retired ranges incorrectly
Also Improve:
- Standardise failure accounting, use null to represent single reply timeouts
- BurnTest record/replay to/from file
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20878
As per CASSANDRA-20045, we want to prevent full repair against
disk full scenarios. Current protection exists only for incremental
repair. This change updates the config name to not be
incremental repair specific, using the Replace annotation.
patch by Himanshu Jindal; reviewed by David Capwell, Jaydeepkumar Chovatia for CASSANDRA-20045
ninja: remove unused imports in CommandsForRanges to pass checkstyle
Patch by Dmitry Konstantinov; reviewed by Stefan Miklosovic, Caleb Rackliffe for CASSANDRA-20842
- Fix erroneous call to registerWithDelay with absolute deadline
- ExecuteSyncPoint should discount votes from unbootstrapped replicas
- Bootstrap no longer needs to first ensure durability (now ExecuteSyncPoint discounts votes from unbootstrapped replicas)
- Progress stall with home shard stopping before Stable is propagated to all shards
- Only upgrade Durability.HasPhase if we have queried all shards
- Incorrectly inferring Durability in CheckStatus.finish
- Incorrectly inferring/propagating stable from fast unstable reply; clarify to prevent further mistakes
- MaxDecidedRX should track separate hlc bounds for filtering non-RX dependencies
- minGcBefore.hlc() can move backwards across epochs, even if each shard moves forwards; must track minHlc directly
- slowTimeout init in ExecuteTxn.LocalExecute
- TxnId.parse for RV
Also improve:
- Don't query recovery state if fast path durably decided
- Support deferred partial dep deserialisation
- Support both orientations of KeyDeps/RangeDeps
- Support partialDeps as ByteBuffer
Also improve in Cassandra:
- Deps serialization and Journal skipping
- Don't inflate when reading from cache for CommandsForRanges
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20847
This also allows overriding complex settings as a JSON value and adds documentation about these overrides to conf/jvm-server.options
patch by Paulo Motta; reviewed by Stefan Miklosovic, David Capwell for CASSANDRA-20749
and more reliably avoid initialising recovery progress log state of transactions that cannot yet make progress
Also fix:
- Harden AccordExecutor state cleanup to failures
- Handle SAVING state in AccordCache.tryEvict, as now possible to save for reasons besides eviction so normal to both be in evict queue and saving
- Infer invalid in MaybeRecover and FetchData
- MaybeRecover sometimes aborts before home shard knows outcome
- Epoch sync with VisibilitySyncPoint
- Retired implies synced
- Don't interpret force repair as excluding nodes from Accord sync conditions
- TxnData.without
Also improve:
- Add Topology.removedNodes
- If Durability implies we can fetch a status, update the waiting state to fetch it
- DurableBefore debug table should have searchable txnId
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20832
The map lookup (with an implicit auto-boxing) can be replaced with a plain arithmetic operation.
A unit test is used to ensure that the assumption about serialization version incrementing for new versions is still correct.
greaterThanOrEqual method is removed as unused.
Patch by Dmitry Konstantinov; reviewed by Stefan Miklosovic for CASSANDRA-20816
A flushing range is a combination of partial and full shards, for full shards we use write time captured values for count and total size of partition keys, for partial shards we iterate over keys
When we iterate over partial shards we count key bytes only instead of reading them and also try to skip tokens full parsing
Patch by Dmitry Konstantinov; reviewed by Branimir Lambov for CASSANDRA-20760
Also fix:
- Catch exceptions thrown by Task.cleanupExclusive to ensure we do not corrupt SequentialExecutor state
- ConcurrentModificationException with CommandStore.waitingOnSync
- Exclude promisedHlc that are in the future, even if not equal to Long.MAX_VALUE
- Filter CFK on load as not expected to be up to date (for later on demand filtering validation)
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20821
patch by Romain Hardouin; reviewed by Stefan Miklosovic, Dmitry Konstantinov for CASSANDRA-20494
Co-authored-by: Stefan Miklosovic <smiklosovic@apache.org>
since later quorums may include the bootstrapping node which does not participate in the durability of preceding transactions
Also Improve:
- Apply MaxDecidedRX filtering to CommandsForKey RX dependencies
- Optimise AbstractRanges.sliceMinimal (burn test hotspot)
- Don't start shard schedulers on topology changes if not already started
- Only registerTransitive if waitingOnSync
- Reserve DurabilityRequest until ShardDurability is started
- Don't notify progress log if stopped
- Remove duplicated CFK unmanaged filtering
Also fix:
- Edge case in notification across bootstrap boundary by resubmitting Unmanaged to be recomputed
- Serialization of CommandsForKey.TxnInfo.missing() collection when non-identity flag bits are present
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20811
patch by Caleb Rackliffe; reviewed by Andres de la Peña for CASSANDRA-18112
Co-authored-by: Caleb Rackliffe <calebrackliffe@gmail.com>
Co-authored-by: Andres de la Peña <a.penya.garcia@gmail.com>
- Remove from CFK any unapplied transactions we know cannot apply
- Force notification of waiting commands in CFK on replay
Also fix:
- Don't truncateWithOutcome if pre bootstrap or stale
- Fix RangeDeps.without(RangeDeps)
- Fix InMemoryCommandStore replay bug with clearing DefaultLocalListeners
- Ensure SaveStatus and executeAt are updated together to prevent corruption via expunge
Improve:
- Inform home shard that command is decided if we cannot execute, to avoid recovery contention
- Don't recover sync points on the fast path
- Don't calculate recovery info for RX (since we don't use it anymore, so no need to do the work)
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20797
This commit only contains in-jvm dtest, logically same as in 5.0, which is ignored as it would fail.
It was identified as part of CASSANDRA-19902 review that trunk branch returns STARTING instead of JOINING operation mode.
This discrepancy between 5.x and trunk is meant to be solved under CASSANDRA-20795.
Replace io.airlift:airline dependency with info.picocli:picocli across
all nodetool command implementations. This migration includes:
- Convert 160+ nodetool command classes from airline to picocli
- Add AbstractCommand base class for commands and utility methods
- Add NodetoolCommand top-level class for the cli utility
- Update all command classes to use @Command, @Option, and @Parameters
- Add plain text files to test command help output
- Add mock test classes for improved test coverage and parse validation
- Modify test infrastructure to work with picocli-based commands
- Add new layouts for cli formatting to preserve backwards compatibility
The migration maintains backward compatibility while providing improved
command-line parsing, better help system, and more robust argument
validation through picocli enhanced features.
patch by Maxim Muzafarov; reviewed by Caleb Rackliffe, Dmitry Konstantinov, Stefan Miklosovic for CASSANDRA-17445
- DurableBefore.fullyContainedIn should compare txnId
Also fix:
- Messages with nullable state should check if they are cancelled after reading the state but before using it
- Don't snapshot during replay
- CFK.updateRedundantBefore incorrectly updating mayExecute and sharing byId in some cases
- Refine GC with global durability bound
- Fix JournalGCTest
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20786
Also fix:
- Limit truncation to TruncatedApplyWithOutcome until data is persisted durably to local store
- IntervalUpdater not invoking super.close()
- Do not invoke preRunExclusive without holding lock
- IntervalUpdater not correctly initialise BranchBuilder.inUse
- AccordExecutor should notify if more work on unlock of caches
- Relax paranoid CFK validation during restart
Also improve:
- Flush logs before System.exit
- Start/stop progress log explicitly
- Limit progress log concurrency
- Clear heavy fields in some messages once processed
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20780
patch by Yuqi Yan; reviewed by Brandon Williams, Maxwell Guo, Stefan Miklosovic for CASSANDRA-19552
Co-authored-by: Stefan Miklosovic <smiklosovic@apache.org>
- PreLoadContext descriptions
- Introduce LoadKeysFor so we can avoid loading range transactions except where necessary
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20758
Also fix:
- slowCoordinatorDelay calculation for locally truncated command throws ISE
- Bad cast of Truncated during replay
- Don't throw IllegalStateException in Invariants.expect if accord.testing == false
- Replay of empty segment throws NPE
Also improve:
- Support tracing of recovery and home progress
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20771
- Don't try to update metrics when no TxnId (e.g. GetMaxConflict)
- maybeExecuteImmediately did not guarantee mutual exclusivity
- Cancellation of a running 'plain' task could corrupt AccordExecutor state
- GetLatestDeps message serializer
- txn_blocked_by StackOverflowError
- Not updating CommandsForKey in all cases on restart
Also Improve:
- TableId.from/toString
- Route toString methods
- Tracing coverage of FetchRoute
- Replay command store parallelism
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20763
- Use AsymmetricComparator for seeking
- Reimplement AbstractTransformer for more efficienct operation when only transforming a subset (i.e. Subtraction)
- Reuse source node IntervalMaxIndex calculations for first branch level (to save iterating leaves)
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20756
- WatermarkCollector should not report same closed/retired epoch N times
- AccordSyncPropagator can merge pending requests and back-off retries
- AccordCommandLoader should notify listeners
- AccordSegmentCompactor should estimate number of keys to ensure bloom filters work
- txn_blocked_by table should report what it can, not throw IllegalStateException
- Permit uncompressed system tables
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20754
- Journal debugging vtable support
- Background task tracing support
Fix:
- HLC_BOUND only valid for strictly lower HLC
- HAS_UNIQUE_HLC can only be safely computed if READY_TO_EXECUTE
- Break recursion in CommandStore.ensureReadyToCoordinate
- Fix find intersecting shard scheduler
- Separate adhoc ShardScheduler from normal to avoid overwriting
- Should still use execution listeners to detect invalid reads for certain transactions even with dataStoreDetectsFutureReads
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20746
- Lock inversion when restarting durability for erased sync point
- Initialise durability cycle start time
Improve:
- Improve durability reporting
- Timeout durability requests
- DurabilityQueue concurrency should limit only until quorum is achieved
- Some exceptions that may be thrown when starting coordination may not be propagated
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20328
- Cannot shrink CommandsForKey if loading pruned
- NoSpamLogger to suppress AccordSyncPropagator repeats
- Minor performance improvement to BTree.Subtraction
- EphemeralReads should retry in a later epoch if replication factor changes
- Fix no local epoch for NotAccept
- Invalidate a command with no route but for which we know we own some key that has applied locally
- Don't pre-merge existing DurableBefore, to reduce duplicate/redundant persistence
- Misc purging bugs and improve testing of purging
patch by Benedict; reviewed by Alex Petrov for CASSANDRA-20739
Sunil Ramchandra Pawar