- now() functions must be deterministic (and derived from Accord timestamp)
- tombstone GC and TTL evaluation must be deterministic and based on both Accord timestamp and Accord GC mechanisms (that guarantee completeness of execution)
patch by Benedict; reviewed by Alex Petrov and Ariel Weisberg for CASSANDRA-21376
- consumer and producer threads wait signal without acquiring the lock first
- lock owners may prepare more work than they need, moving some dynamically-adjusted portion of the work from the prioritised lock-managed structures onto a non-blocking queue, so that other threads may consume work from there; the portion is continually micro-adjusted to target some available work whenever the lock is acquired.
- adopts/supports some features of the SEPExecutor:
- threads may auto-adjust the number of running threads based on how much time is collectively spent waiting, to minimise time spent signalling
- consumers may (timed-sleep) poll rather than await a signal, reducing the number of kernel interactions needed; relying on the auto-adjustment to bound the time the scheduler spends waking threads with no work to do
Also Fix:
- Client Result should not be persisted or included in Command object at any time
patch by Benedict; reviewed by Alex Petrov and Ariel Weisberg for CASSANDRA-21375
The following subcommands have been added:
* abortbootstrap Cancel and undo an inflight bootstrap
* abortmove Cancel and undo an inflight token move
* abortdecommission Cancel and undo an inflight decommission
* assassinate Remove a node from cluster metadata
* resetcms Redefine the CMS membership
* move Modify a node's (single) owned token
* describe Output a summary of the cluster metadata
* forcejoin Force a registered or joining node into a JOINED state
* print Output a full rendering of cluster metadata
* printdirectory Output a full rendering of the directory
* printdataplacements Output the full data placements
Patch by Venkata Harikrishna Nukala; reviewed by Alex Petrov and Sam Tunnicliffe
for CASSANDRA-19151
Follow-up to the trunk PR #4807 forward-merge for cassandra-5.0. The
trunk R1 commit (8e0700a7cb on the chain leading to 32826fe563)
rewrote reference/cql-commands/commands-toc.adoc to retarget 38
broken xref:reference/cql-commands/<page>.adoc[...] entries to the
corresponding anchors in developing/cql/{ddl,dml,functions,mvs,
security,types}.adoc, kept 6 entries that still resolve under
cassandra:reference/cql-commands/, and dropped 4 DSE-only entries
(RESTRICT, RESTRICT ROWS, UNRESTRICT, UNRESTRICT ROWS).
The same transformation is applied here to cassandra-5.0. The trunk
commit was not cherry-pickable because 5.0's commands-toc.adoc had
diverged from trunk's pre-R1 version by ~9 lines (the DSE-only
entries plus an unrelated formatting drift); a direct edit replacing
the file with trunk's post-R1 content was the cleanest application.
One trunk-only entry is omitted: LIST SUPERUSERS (target
developing/cql/security.adoc#list-superusers-statement). That anchor
does not exist on cassandra-5.0; the LIST SUPERUSERS command was
added after 5.0.
All 29 retarget anchors plus the 6 cassandra:reference/cql-commands/
target pages verified to exist on upstream/cassandra-5.0.
patch by Patrick McFadin; reviewed by TBD for CASSANDRA-21342
Forward-merge of the trunk fix (commit 32826fe563) to cassandra-5.0.
Restricted to the changes whose broken-target patterns exist on this
branch.
Two trunk commits intentionally omitted:
- P1 (memtable.adoc retarget): the memtable sections containing the
broken xref were added on trunk only and do not exist on 5.0.
- R1 (commands-toc.adoc rewrite): commands-toc.adoc on 5.0 diverges
from trunk by ~9 lines; the 38-row retarget mapping will be applied
as a separate follow-up commit on this branch.
patch by Patrick McFadin; reviewed by TBD for CASSANDRA-21342
Resolve broken cross-module xrefs and image/anchor targets across the
cassandra docs tree. Companion to apache/cassandra-website#319 (merged
2026-05-13) under the same JIRA umbrella.
patch by Patrick McFadin; reviewed by Brandon Williams for CASSANDRA-21342
- TransactionStatement token aware routing
- Mitigate convoy effect:
- ExecuteTxnBacklog v1 can execute single key transaction backlogs and disseminate the result
- Direct local execution possible for single key transactions
- Use shardAppliedBefore instead of gcBefore to cleanup CFK faster
Also Improve:
- Introduce distributed tracing
- Combine RejectBefore and MaxConflicts
- Self-addressed messages are delivered directly
- Disable AccordSyncPropagator by default, as incompatible with large clusters
- FastPathStrategy.SIMPLE should not modify fast path contents; FastPathStrategy.UP introduced to adopt this behaviour
- Configurable queue prioritisation
- ProtocolModifiers mostly final
- Remove unnecessary condition check when serializing TxnUpdate
Also Fix:
- SequentialExecutor ownership bug
- BTree.XUpdater.reset()
patch by Benedict; reviewed by Alex Petrov and Ariel Weisberg for CASSANDRA-21361
use compression ratio to scale the amount of remaining disk usage
CompactionInfo::estimatedRemainingWriteBytes is uncompressed, causing compaction to be rejected due to size when it has space to complete
patch by Matt Byrd; reviewed by Dmitry Konstantinov, Marcus Eriksson for CASSANDRA-21245
Co-authored-by: Jon Meredith <jmeredithco@apple.com>
- Clean Shutdown/Restart
- Rebootstrap to allow nodes to rejoin consensus if they are out of sync, or did not shutdown cleanly
Improve:
- Improve efficiency of BTreeReducingRangeMap
- DurableBefore backed by BTreeReducingRangeMap
- Soft reject new transactions when a replica has a backlog of work
- system_accord_debug.command_store_ops supports starting journal replay
Fix:
- Ensure SequentialExecutor.owner is unset only by the owner
- Detect and avoid taking two AccordExecutor locks simultaneously
- MaxConflicts serializer
- tryToExecuteListening after replay, to handle invalidated dependencies
- TxnNamedRead does not close a RowIterator, leading to native memory leaks
- GetLatestDepsNack serialization
- journal.readLast() did not read last
- DefaultRemoteListeners not correctly synchronised
- RangeTxnScanner cancellation assumes was already started
- Start cfk compaction before replay
- txn_graph should avoid visiting parents twice (possible if two different dependency chains connecting them in the graph)
- Topology.cloneEquivalentWithEpoch should also share nodeLookup and ranges, especially to accelerate computeWaitForEpoch/computeScope
- Do not invoke slowReplicaDelay or slowCoordinatorDelay during restore
- Do not fail if slowReplicaDelay or slowCoordinatorDelay are invoked without knowing the transaction
patch by Benedict; reviewed by Alex Petrov and Ariel Weisberg for CASSANDRA-21355
SinglePartitionReadCommand.Group#create - typical single partition select, use singletonList instead of ArrayList + Object[]
SelectStatement#getSliceCommands - remove unnessesary cloning of partition key, it is a part of a very old patch, now we copy all values from Netty buffers
SelectStatement#getSliceCommands - typical single partition select, use singletonList instead of ArrayList + Object[]
SinglePartitionReadQuery.Group#maybeValidateIndex, avoid iterators for restrictionSet if a full partition is selected
patch by Dmitry Konstantinov; reviewed by Francisco Guerrero, Stefan Miklosovic for CASSANDRA-21351
Maxim Muzafarov