RabbitMQ v4.2.7

RabbitMQ 4.2.7 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

• A virtual host could be falsely considered to be deleted in certain metadata store error and timeout scenarios.

  GitHub issue: #16422

• Passive queue and exchange declarations are now allowed for users that have any permission on the virtual host (configure, write, or read), not only configure.

  GitHub issue: #16272

• Classic queue message store: garbage collection is now stopped cleanly during node shutdown.

  GitHub issue: #15498

• Fixed a bug where quorum queue's at-least-once dead lettering could direct commands to the wrong member (replica).

  GitHub issue: #16203

• Stream queue argument validation was improved.

  GitHub issue: #16285

Enhancements

• channel_max was renamed to max_channels in rabbitmq.conf. The original name is still supported as an alias.

  GitHub issue: #16347

• connection_max was renamed to max_connections in rabbitmq.conf. The original name is still supported as an alias.

  GitHub issue: #16347

• The per-node max_connections limit is now enforced for AMQP 1.0 connections as well as AMQP 0-9-1 ones.

  GitHub issue: #16300

• The permission cache is now traversed less often during AMQP 1.0 management and AMQP 0-9-1 channel checks.

  GitHub issue: #16274

Stream Plugin

Bug Fixes

• Stream protocol: an open frame with empty properties is now handled correctly.

  GitHub issue: #16341

Enhancements

• It is now possible to cap the maximum number of concurrent Stream Protocol client connections using the stream.max_connections configuration key in rabbitmq.conf.

  GitHub issue: #16341

Management Plugin

Bug Fixes

• HTTP API GET /api/connections could return a 500 response when STOMP connections were present.

  GitHub issue: #16435

Enhancements

• It is now possible to cap the maximum number of concurrent HTTP API connections using the management.tcp.max_connections, management.ssl.max_connections configuration keys in rabbitmq.conf.

  GitHub issue: #16407

• The peer (client) certificate serial number is now exposed in the management UI and select CLI commands.

  GitHub issue: #16463

Prometheus Plugin

Enhancements

• It is now possible to cap the maximum number of concurrent HTTP API connections using the prometheus.tcp.max_connections, prometheus.ssl.max_connections configuration keys in rabbitmq.conf.

  GitHub issue: #16407

MQTT Plugin

Bug Fixes

• The MQTT connection process no longer fails and logs an exception when keepalive checks encounter socket errors on an already-closed connection.

  GitHub issue: #16391

Enhancements

• It is now possible to cap the maximum number of concurrent MQTT client connections using the mqtt.max_connections configuration key in rabbitmq.conf.

  GitHub issue: #16367

Federation Plugin

Bug Fixes

• Federation links could fail to start during rolling cluster restarts.

  GitHub issues: #16234, #16224

LDAP Plugin

Enhancements

• New rabbitmq.conf configuration settings for TLS cipher suites: auth_ldap.ssl_options.ciphers.*.

  GitHub issue: #16226

HTTP Auth Backend Plugin

Enhancements

• New rabbitmq.conf configuration settings for TLS cipher suites: auth_http.ssl_options.ciphers.*.

  GitHub issue: #16226

Auth Backend Cache Plugin

Bug Fixes

• The cache was not effective for reconnecting clients.

  GitHub issues: #16255, #16258

Trust Store Plugin

Bug Fixes

• A user-provided fail_if_no_peer_cert value in the plugin's TLS options is now respected. Previously, an internal default could override the configured value.

  GitHub issue: #16201

Enhancements

• New rabbitmq.conf configuration settings for TLS cipher suites: trust_store.ssl_options.ciphers.*.

  GitHub issue: #16226

Dependency Changes

• ra was upgraded to 2.17.3
• cuttlefish was upgraded to 3.7.0
• cowboy was upgraded to 2.15.0
• cowlib was upgraded to 2.16.1
• gun was upgraded to 2.3.0