RabbitMQ 4.2.3 is a maintenance release in the 4.2.x release series.
It is strongly recommended that you read 4.2.0 release notes
in detail if upgrading from a version prior to 4.2.0.
Minimum Supported Erlang Version
RabbitMQ and Erlang/OTP Compatibility Matrix has more details on Erlang version requirements for RabbitMQ.
Nodes will fail to start on older Erlang releases.
Changes Worth Mentioning
Release notes can be found on GitHub at rabbitmq-server/release-notes.
Core Server
Bug Fixes
-
Default queue type handling is now more defensive, avoiding an issue where
attempts to declare a queue in a virtual host without any DQT set would result
in aPRECONDITION_FAILEDexception instead of falling back to the classic queue type
for DQT. -
Classic queue recovery on Windows could fail due to an OS-specific file locking behavior.
Such failures are now retried in two more contexts.GitHub issue: #15136
-
Certain exchange update operations in Khepri could cause severe contention.
GitHub issue: #15236
-
Topic exchange binding deletions could leave orphaned trie edges in the Khepri projection,
potentially causing a slowly creeping memory leak.GitHub issue: #15025
-
When a client that owns an exclusive queue disconnects and immediately reconnects and redeclares the same queue
(under the same name), RabbitMQ node could delete the new queue depending on the timing of events.Previously the only workaround was to use exclusive server-named queues for clients that exhibited
this behavior. Now RabbitMQ nodes take internal owner identity into account and will remove
the original queue but not the new one.GitHub issue: #15276
-
"Other ETS" and "Other system" memory metrics could end up being reported as negative values
due to concurrent ETS table updates, deletion and creation on the node.GitHub issue: #15289
-
mirrored_supervisor:child/2could fail with abadmatchexception
when a significant enough number of shovels (or federation links) was removed.GitHub issue: #15229
-
Quorum queue could run into a logging exception during node drain.
GitHub issue: #15212
Enhancements
-
Topic binding deletion in Khepri is now significantly more efficient.
Deleting 100k topic bindings could previously take up to 30 minutes and now takes
some 3-4 seconds.GitHub issue: #15214
-
It is now possible to
rabbitmq-queues shrinkonly a subset of quorum queues on
a node using a pattern (a regex).GitHub issue: #15021
-
CRL (Certificate Revocation List) cache can now be configured via
rabbitmq.conf.
Federation Plugins
Bug Fixes
-
Restored exchange federation compatibility in mixed 4.2.x/4.1.x multi-node clusters.
GitHub issue: #15252
Enhancements
-
Federation links and their connections are now stopped in parallel.
This significantly improves shutdown time for nodes with many (into thousands) federation links.
GitHub issue: #15271
-
Federation links no longer restart during plugin or node shutdown.
For nodes with hundreds or thousands of federation links, link recovery could
significantly delay node shutdown.GitHub issue: #15258
-
Federation links use AMQP 0-9-1 connections to remote nodes (clusters).
Previously the timeout used when those connections are closed was fixed to 10 seconds.
Now it is configurable viarabbitmq.confin milliseconds:# 3 seconds for exchange federation federation.exchanges.connection_close_timeout = 3000 # 3 seconds for queue federation federation.queues.connection_close_timeout = 3000
The maximum supported value is 5 seconds (5000 ms).
GitHub issue: #15268
CLI Tools
Enhancements
-
rabbitmq-streams growandrabbitmq-streams shrinkare new commands that mirror existing
rabbitmq-queues growandrabbitmq-queues shrinkfunctionality for streams.GitHub issue: #15189
MQTT Plugin
Enhancements
-
A new configuration option,
mqtt.disconnect_on_unauthorized, controls whether
MQTT connections are closed upon authorization failures (for example, an attempt to
consume from a topic the client has no permission for).When set to
false, the connection remains open and an appropriate protocol-level
response is sent to the client instead.The default value is
true, same as RabbitMQ MQTT implementation's historic behavior.GitHub issue: #15201
Management Plugin
Bug Fixes
-
OAuth 2:
preferred_auth_mechanismandstrict_auth_mechanismare no longer validated
when not used (configured).GitHub issue: #15148
etcd Peer Discovery Plugin
Bug Fixes
-
When credentials were provided, the password was double-encrypted, resulting in
etcd authentication failures.GitHub issue: #15191
HTTP Auth Backend Plugin
Bug Fixes
-
The
customize_hostname_checkTLS option was unintentionally ignored.GitHub issue: #15184