Release v2.15.0-RC.1

Changelog

This release also contains all changes up to and including v2.14.6.

Go Version

• 1.27.1 (#8551)

Added

JetStream

• Desired state metalayer (#8432, #8437, #8439, #8443, #8452, #8460, #8476, #8576)
  • A new desired state reconciliation engine for streams and consumers considerably improves the safety and reliability of asset moves and scales
  • Updating the placement or replication factor midway through an existing scale/move operation, cancelling an in-flight scale/move, or peer-removing is now much safer
• Cancel stream move endpoint (#8476)
  • An in-flight scale/move operation on a stream can be cancelled and the asset returned to its original placement using the new $JS.API.STREAM.CANCEL_MOVE endpoint
• Evacuate endpoints (#8443)
  • The new $JS.API.SERVER.EVACUATE endpoint can safely evacuate streams, and any consumers on those streams, from a node
  • The new $JS.API.STREAM.PEER.EVACUATE.* endpoint can safely evacuate a peer, and any consumers on that peer, from a stream
  • These operations combined allow for maintenance operations with full transfer of data and state without having to peer-remove first
• Metalayer rescue for disaster recovery (#8408)
  • The new $JS.API.META.RESCUE endpoint can temporarily lower the quorum-needed for the metalayer, in order to facilitate the recovery of a system where nodes have been permanently lost and the metalayer cannot reach quorum
• Stream backup and restore v2 (#7882)
  • A new backup format for stream snapshots which reads out per-message rather than per-block
  • The new backup format also now correctly includes non-replicated consumers on follower nodes
• Detect source stream recreation (#8384)
  • The server now detects a source stream being recreated, restarting the sourcing back from the beginning, ensuring new messages are sourced
• Stream source indexing (#8282, #8516, #8283)
  • Restarts and leader changes previously required expensive backward scans through the stream to find the last sourced indices. These are now persisted in an index for instant lookup.
• Domain-prefixed JS API in system account (#8429)
  • When a system account is bridged between the hub and a leaf node, the domain-prefixed JS API can now be used to operate on the leaf node while directly connected to the hub

Changed

JetStream

• Streams now have a default limit of 1000 consumers, unless max_consumers is specified in the stream config or account limits (#8337, #8566)
  • Applications planning to use a large number of consumers on a stream should configure max_consumers in the stream config or account limits to an appropriately high number
  • The server-wide default of 1000 can be overridden by setting default_max_consumers in the JetStream limits, or can be disabled by setting to -1
  • This limit does not affect existing consumers and will not result in consumer deletions, only the creation of new consumers is prevented
• Sync changes for replicated streams (#8447)
  • When the sync_interval is set to always, replicated streams now sync their WAL entries but no longer sync upper stream layer writes
  • The synced log allows the stream to recover safely, but removing unnecessary syncs from the upper stream layer dramatically improves performance
  • Non-replicated R1 streams are not affected by this change and will continue to sync at the stream layer as normal
• The js_raft_delete_range feature is now enabled by default (#8520)

Leafnodes

• The no_advertise option no longer includes the hub's own listener address (#8451)

Improved

JetStream

• Shorter wait for durable source/mirror consumer resets (#8323)
  • When using durable consumers for sourcing or mirroring, the heartbeats now short-circuit the recreation backoff

Fixed

Leafnodes

• Leafnode isolation using request_isolation, or with hub-enforced isolate, now works correctly across cluster nodes (#8504)

Complete Changes

v2.14.6...v2.15.0-RC.1