rabbitmq/rabbitmq-server v3.8.12-rc.3

RabbitMQ 3.8.12-rc.3

on GitHub

RabbitMQ 3.8.12-rc.3

RabbitMQ 3.8.15-rc.3 is a maintenance release candidate.

Erlang/OTP Compatibility Notes

This is the first release in the post-Bintray era.
Because Bintray shuts down on May 1st, 2021, this version is not distributed via Bintray.
Instead, Cloudsmith and PackageCloud are used.

This release is the last release to support Erlang 22.3.
Erlang 23 is highly recommended
for best forward compatibility with future RabbitMQ versions.

Provisioning Latest Erlang Releases explains
what package repositories and tools can be used to provision a recent version of Erlang 23.x.

Upgrade and Compatibility Notes

Upgrade Doc Guides and Change Log

See 3.8.0 release notes upgrade and
compatibility notes first if upgrading from an earlier release series (e.g. 3.7.x).

See the Upgrading guide for general documentation on upgrades and
RabbitMQ change log for release notes of other releases.

Getting Help

Any questions about this release, upgrades or RabbitMQ in general are welcome on the RabbitMQ mailing list
and RabbitMQ community Slack.

Changes Worth Mentioning

Core Server

Bug Fixes

• Maintenance mode no longer transfers leaders of classic mirrored queue.

  The original transfer implementation was not guaranteed to be safe when only a
  subset of cluster nodes hosted replicas. In addition, the process could take
  a lot of time in environments with a lot of classic mirrored queues, more
  than in case of node shutdown.

  Quorum queue leadership transfer is still performed as it is dramatically more
  efficient and never suffered from any downsides of leadership transfer of CMQs.

  GitHub issue: #2749

• Exclusive queues that happen to be matched by classic queue mirroring policies
  will no longer be considered for rebalancing operations since they are not
  actually mirrored (the lifecycle is by design tied to a single client connection).

  GitHub issue: #2795

• Default replica count for quorum queues was using an incorrect configuration key name.
  The default value is now 3, so in a cluster of five or seven nodes, only three
  will host replicas for newly declared quorum queues. One replica is the node to which
  the declaring client is connected to, two others are selected randomly.

  Declaring connections can control the number of replicas using the x-quorum-initial-group-size
  optional queue argument at declaration time.

  GitHub issue: #2759

• Default runtime busy waiting settings were
  changed to none by default, which reduces CPU footprint on nodes that are mostly idle. The values
  can be overridden for workloads that benefit from different values.

  Contributed by @carlhoerberg (CloudAMQP)

  GitHub issue: #2803

• Definition import now imports runtime parameters after exchanges, queues, and bindings
  to reduce the likelihood of starting dynamic Shovels from racing with topology
  imports.

  GitHub issue: #2798

• Memory monitor could run into an exception if queried very early on node boot
  before it was fully initialized.

  Contributed by @tomyouyou.

  GitHub issue: #2733

Enhancements

• rabbitmq.conf validation of TLS certificate and private key paths is now more thorough:
  it checks if the files have read or read/write permissions instead of checking if it can read
  the file's metadata.

  GitHub issue: #2685

CLI Tools

Enhancements

• rabbitmqctl close_all_user_connections is a new command that closes all connections that
  authenticated using a specific username:

  rabbitmqctl close_all_user_connections "user-99fc15d3f" "closed to force reconnection"
  

  GitHub issue: #2715

Prometheus Plugin

Bug Fixes

• AuthN authentication attempts metrics produced duplicate TYPE and HELP strings in
  the scraping API endpoint output.

  Some metrics were renamed to avoid duplication. The new names are auth_attempts_detailed_total,
  auth_attempts_detailed_succeeded_total, and auth_attempts_detailed_failed_total.

  This issue is specific to RabbitMQ 3.8.10 and 3.8.11.

  GitHub issue: #2740

LDAP Plugin

Enhancements

• The plugin now supports two new configuration settings that control SNI and hostname verification
  behavior for TLS-enabled LDAP client connections:

  # leave out to keep the default behavior (exact hostname matching)
  auth_ldap.ssl_options.hostname_verification = wildcard
  
  # set to none to disable SNI
  auth_ldap.ssl_options.sni = a.rabbitmq.hostname.dev

  These changes are based on the research and suggestions from Patrick @patcable Cable.

  GitHub issue: #2805

Shovel Plugin

Enhancements

• Dynamic Shovels now can specify optional queue arguments for
  the queues they declare. Note that these settings will not have any effects for cases where the plugin
  uses already existing queues.

  This allows for the Shovel-managed queues to be quorum. For the arguments
  that must not be provided at queue declaration time, policies
  is the right approach.

  The arguments are specified using the "" and "" arguments for source and destination queues, respectively:

  {
    "src-protocol": "amqp091",
    "src-uri": ["amqp://localhost"],
    "src-queue": "src-queue",
    "dest-protocol": "amqp091",
    "dest-uri": ["amqp://localhost"],
    "dest-queue": "dest-queue",
    "src-queue-args": {
      "x-queue-type": "quorum"
      },
    "dest-queue-args": {
      "x-queue-type": "quorum"
      }
    }

  GitHub issue: #2799

AuthN/AuthZ Cache Plugin

Enhancement

• Cache operation timeout has been increased to 15s (same as the channel operation timeout in the core).
  This prevents sporadic timeouts in heavily loaded systems.

  GitHub issue: #2792

RabbitMQ Erlang Client

Bug Fixes

• The client performed hostname resolution twice even if IP version preference was specified by the user.

  Contributed by Pawel @haljin Antemijczuk.

  GitHub issue: #2748

Dependency Upgrades

No dependency changes.

Source Code Archives

To obtain source code of the entire distribution, please download the archive named rabbitmq-server-3.8.12.tar.xz
instead of the source tarball produced by GitHub.