3.8.10 - Rabbitmq Server

RabbitMQ 3.8.10

Important: this release has been superseded by 3.8.11 which addresses a couple of bugs specific to this release (3.8.10)

All users are advised to consult the set of changes in this release but then upgrade straight to 3.8.11 or a newer version if available and skip this release.

RabbitMQ 3.8.10 is a maintenance release. Besides containing several bug fixes, it introduces a couple new features for quorum queues.

This release no longer supports Erlang 21.3.

Erlang/OTP Compatibility Notes

This release requires Erlang 22 or Erlang 23.

Erlang 21.3 is no longer supported. 22.3 or 23.1 releases are recommended.

Provisioning Latest Erlang Releases explains what package repositories and tools can be used to provision latest patch versions of Erlang 22.3.x.

Upgrade and Compatibility Notes

Deprecations

This release deprecates boot time definition import build into the management plugin. The feature still exists but is no longer documented or tested. Please switch to the built-in definition import mechanism:

ini

# DEPRECATED, requires management plugin to be enabled,
# does not support import of definitions that depend on plugins
# (e.g. Shovels or custom exchanges)
management.load_definitions = /path/to/definitions/file.json

ini

# built-in feature, supports import of definitions
# that depend on plugins (e.g. Shovels or custom exchanges)
load_definitions = /path/to/definitions/file.json

Definition import in the management plugin (management.load_definitions) will be removed in a future RabbitMQ release.

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.

Upgrading to Erlang 22.x or Later Versions

When upgrading to this release from 3.7.15 or an older version, extra care has to be taken.

Because older RabbitMQ CLI tools can be incompatible with Erlang 22+ releases, RabbitMQ must be upgraded at the same time as Erlang.

Alternatively the node can be upgraded to 3.7.18 on Erlang 21.3 first, then Erlang 22.x or 23.x, then RabbitMQ to the most recent 3.8.x release.

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

Starting with 3.8.0, an unintentionally introduced assertion could prevent classic mirrored queue mirrors from starting successfully in case the primary replica changed concurrently with their startup.

GitHub issue: rabbitmq/rabbitmq-server#2449
Repeated polling of a quorum queue with basic.get that yielded an empty response could result in an unbounded growth of log segment files on on disk.

GitHub issue: rabbitmq/rabbitmq-server#2651
RabbitMQ core plugin activation was revisited to be closer to that of 3.7.x. This does not any related improvements w.r.t. definition import, e.g. those introudced in RabbitMQ 3.8.6.

GitHub issue: rabbitmq/rabbitmq-server#2656
Syslog dependency was not started correctly. This meant no log messages were sent to Syslog.

GitHub issue: rabbitmq/rabbitmq-server#2456
rabbitmq-diagnostics check_if_node_is_quorum_critical returned a false positive for a node marked for maintenance. Given the refinement to the rabbitmq-upgrade drain command in rabbitmq/rabbitmq-server#2474, rabbitmq-diagnostics check_if_node_is_quorum_critical now will unconditionally return a success if target node is under maintenance.

GitHub issue: rabbitmq/rabbitmq-server#2469
Queues could update their internal bookkeeping state incorrectly in some cases, leading to a file_handle_cache operation exception.

GitHub issue: rabbitmq/rabbitmq-server#2488

Enhancements

Quorum queues now can use the reject-publish max length overflow strategy.

GitHub issue: rabbitmq/rabbitmq-server#2407
Quorum queues now support consumer priority.

GitHub issue: rabbitmq/rabbitmq-server#2451

Per-user connection and queue limits. This is similar to per-vhost limits but, as the name suggests, these limits are associated for a given user.

The limits are controlled using CLI tools or the HTTP API:

# limits user "user-e8d3f85c" to up to five connections and ten channels
rabbitmqctl set_user_limits "user-e8d3f85c" '{"max-connections": 5, "max-channels": 10}'

# clears the maximum number of connections limit for the user
rabbitmqctl clear_user_limits "user-e8d3f85c" "max-connections"

# clears all limits for the user
rabbitmqctl clear_user_limits "user-e8d3f85c" "all"

Contributed by Erlang Solutions, sponsored by CloudAMQP.

GitHub issue: rabbitmq/rabbitmq-server#607, rabbitmq/rabbitmq-server#2380

TLSv1.3 is no longer considered experimental (on Erlang 23) and excluded from TLS listener configuration.

GitHub issue: rabbitmq/rabbitmq-common#415
When a node is put under maintenance, it will now stop all local quorum queue replicas after completing leadership transfer. This means that no quorum queue replicas on the node will be considered for leader elections.

GitHub issue: rabbitmq/rabbitmq-server#2474
Nodes now keep track of failed client authentication attempts and expose it as a metric via both the Prometheus endpoint and the HTTP API at GET /api/auth/attempts/{node}.

The tracking is done for every cluster node individually. The protocols that support authentication attempt tracking right now are AMQP 0-9-1, AMQP 1.0 and MQTT.

GitHub issue: rabbitmq/rabbitmq-server#2436
bypass_pem_cache is a new configuration key that makes it possible to disable the cache of PEM files used by the Erlang TLS implementation. This rotated certificates quicker to detect for nodes but can also increase latency for inbound TLS connections, e.g. under high connection churn scenarios.

GitHub issue: rabbitmq/rabbitmq-server#2686
Definition import now safely handles some missing queue object arguments.

GitHub issue: rabbitmq/rabbitmq-server#2668
rabbitmq.conf schema now allows for peer certificate chain verification depth to be set to zero. When this value is used, peer certificate must be signed by a trusted CA certificate directly in order for the verification to pass.

GitHub issue: rabbitmq/rabbitmq-server#2493
RABBITMQ_IO_THREAD_POOL_SIZE will no longer be respected by RabbitMQ nodes. It is no longer relevant with supported Erlang versions and will simplify rabbitmq-diagnostics runtime_thread_stats output.

GitHub issue: rabbitmq/rabbitmq-server#2473
The +K runtime parameter is no longer used by RabbitMQ nodes as it has no effect with supported Erlang versions.

Contributed by Ayanda Dube (Erlang Solutions).

GitHub issue: rabbitmq/rabbitmq-server#2470

CLI

Enhancements

It is now possible to enable all feature flags in a single command:
sh
```
rabbitmqctl enable_feature_flag all
```
Note that this will only enable the flags supported by all cluster members.

GitHub issue: rabbitmq/rabbitmq-cli#455
rabbitmq-queues peek is a new command that allows for peeking at a queue position. It is only supported by quorum queues (and not classic queues):
sh
```
# peeks at the head of queue "qq.1" in virtual host "staging"
rabbitmq-queues peek --vhost "staging" "qq.1 1"
```
GitHub issue: rabbitmq/rabbitmq-cli#452
rabbitmq-queues reclaim_quorum_memory is a new command that forces Raft WAL compaction which in most cases should reduce memory footprint of a quorum queue:
sh
```
rabbitmq-queues reclaim_quorum_memory --vhost "staging" "qq.1"
```
GitHub issue: rabbitmq/rabbitmq-cli#453

Bug Fixes

rabbitmqctl rename_cluster_node failed with an error about a missing directory.

GitHub issue: rabbitmq/rabbitmq-cli#457
rabbitmqctl export_definitions exported optional binding arguments as blank.

GitHub issue: rabbitmq/rabbitmq-server#2500
Force removal of a node did not remove it from quorum queue member lists.

GitHub issue: rabbitmq/rabbitmq-server#2414
CLI tools now pick a unique identifier from a pool. Previously the pool of possible values was theoretically unbounded, which could result in an atom table exhaustion condition on long running nodes that had a lot of CLI tool invocations (e.g. CLI tools were used to collect monitoring data frequently).

Such use of CLI tools for monitoring is not recommended: there are better options such as Prometheus and Grafana.

GitHub issue: rabbitmq/rabbitmq-cli#461

MQTT Plugin

Bug Fixes

Raft-based client ID tracker is now significantly more efficient in handling failing or closed connections. This prevents potential high memory usage of tracking tables on the node.

GitHub issue: rabbitmq/rabbitmq-server#2692

Federation Plugin

Bug Fixes

Federation links that failed to connect due to a TCP connection timeout leaked resources. Other connection failure scenarios did not result in a leak.

GitHub issue: rabbitmq/rabbitmq-federation#119

Shovel Plugin

Bug Fixes

An autodeleted Shovel would re-appear on other cluster nodes after the node that hosted it originally was restarted.

GitHub issue: rabbitmq/rabbitmq-server#2655

Prometheus Plugin

Enhancements

GET /metrics/per-object is a new endpoint that always returns individual entity metrics, even if GET /metrics is configured to return aggregated results.

GitHub issue: rabbitmq/rabbitmq-server#2659

Management Plugin

Enhancements

Individual health checks are now available through the HTTP API.

GitHub issue: rabbitmq/rabbitmq-management#844

Bug Fixes

Quorum queue consumer counter on on the queue list page was not updated when consumers were cancelled or failed.

GitHub issue: rabbitmq/rabbitmq-server#2421
The aliveness check endpoint now responds with a 503 Service Unavailable instead of a 500 when it cannot publish a test message, e.g. because a policy with zero message TTL was applied to all queues.

GitHub issue: rabbitmq/rabbitmq-management#855

AWS Peer Discovery Plugin

Bug Fixes

AWS API request errors are now propagated. This means that should an AWS API request fail, the peer discovery subsystem will retry it a limited number of times.

Contributed by Stefan @stefanmoser Moser.

GitHub issue: rabbitmq/rabbitmq-peer-discovery-aws#40

RabbitMQ Erlang Client

Bug Fixes

amqp_channel:call/4 timeouts are now safly reconciled with connection-level timeouts.

Contributed by Ayanda Dube.

GitHub issue: rabbitmq/rabbitmq-server#2660

Windows Installer

Bug Fixes

Windows installer is now signed by a new (rolled) key.

GitHub issue: rabbitmq/rabbitmq-server#2666
The installer now correctly creates directories when RabbitMQ is installed to a different drive from the shell (cmd.exe).

Contributed by Jiahao @Y2Nk4 Guo.

GitHub issue: rabbitmq/rabbitmq-server#2682

Dependency Upgrades

credentials_obfuscation was upgraded from 2.2.3 to 2.3.0
ranch is no longer a dependency of rabbit_common

Source code archives

Warning: The source code archive provided by GitHub only contains the source of the broker, not the plugins or the client libraries. Please download the archive named rabbitmq-server-3.8.10.tar.xz.