RabbitMQ 3.9.4

[michaelklishin]

RabbitMQ 3.9.4 is a maintenance release in the 3.9.x release series.

Please refer to the Upgrading to 3.9 section from v3.9.0 release notes if upgrading from a version prior to 3.9.0.

This release requires at least Erlang 23.2, and supports the latest Erlang 24 version, 24.0.5 at the time of release. RabbitMQ and Erlang/OTP Compatibility Matrix has more details on Erlang version requirements for RabbitMQ.

Changes Worth Mentioning

Release notes are kept under rabbitmq-server/release-notes.
Contributors are encouraged to update them together with their changes. This helps with release automation and more
consistent release schedule.

Core Server

Enhancements

• New Prometheus metrics for alarms:

  • rabbitmq_alarms_file_descriptor_limit 1|0
  • rabbitmq_alarms_free_disk_space_watermark 1|0
  • rabbitmq_alarms_memory_used_watermark 1|0

  While some of the alarms have cluster-wide effect, these metrics are node-local.

  GitHub issue: #2653

• Nodes will now use four more environment variables, if set: RABBITMQ_DEFAULT_USER (overrides default_user in rabbitmq.conf), RABBITMQ_DEFAULT_PASS (overrides default_pass), RABBITMQ_DEFAULT_VHOST (overrides default_vhost) and RABBITMQ_ERLANG_COOKIE (sets shared authentication secret value).
  These variables are not recommended to be used in production but can be the only realistic option in some environment, such as service containers, ECS, and so on.
  Most users should continue using rabbitmq.conf and a securely generated local cookie file.

  GitHub issue: #3299

• Definitions now can be imported from different sources, including those provided by plugins. Original local filesystem source is still supported in a backwards-compatible way.

  The following rabbitmq.conf example uses a local file as the source:

  # equivalent to the classic load_definitions configuration key   
  definitions.import_backend = local_filesystem
  
  definitions.local.path = /path/to/definitions.json

  This rabbitmq.conf example uses a local directory with definition files:

  # equivalent to the classic load_definitions configuration key   
  definitions.import_backend = local_filesystem
  
  definitions.local.path = /path/to/rabbitmq/definitions.d

  In this example config file, definitions are loaded from a URL accessible over HTTPS:

  # downloads definitions over HTTPS
  definitions.import_backend = https
  
  definitions.https.url = https://rabbitmq.eng.megacorp.local/env-1/definitions.json
  
  # client-side TLS options for definition import   
  definitions.tls.versions.1 = tlsv1.2
  definitions.tls.log_level  = error

  GitHub issue: #3249

Dependency Upgrades

No dependency changes in this release.

Source Code Archives

To obtain source code of the entire distribution, please download the archive named rabbitmq-server-3.9.4.tar.xz instead of the source tarball produced by GitHub.

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This discussion was created from the release RabbitMQ 3.9.4.