v5.1.0

Enhancements

• #10858 A new utility function timezone_to_offset_seconds/1 has been added to the rule engine SQL language. This function converts a timezone string (for example, "+02:00", "Z" and "local") to the corresponding offset in seconds.
• #10754 The MQTT bridge has been enhanced to utilize connection pooling and leverage available parallelism, substantially improving throughput. As a consequence, single MQTT bridge now uses a pool of clientids to connect to the remote broker.
• #10782 Added a new deliver_rate option to the retainer configuration, which can limit the maximum delivery rate per session in the retainer.
• #10598 Provided a callback method of Unary type in ExProto to avoid possible message disorder issues.
• #10790 Reduced the overhead during configuration reads by optimizing the configuration read mechanism.
• #10910 The data bridge resource option auto_restart_interval was deprecated in favor of health_check_interval, and request_timeout was renamed to request_ttl. Also, the default request_ttl value went from 15 seconds to 45 seconds. The previous existence of both auto_restart_interval and health_check_interval was a source of confusion, as both parameters influenced the recovery of data bridges under failures. An inconsistent configuration of those two parameters could lead to messages being expired without a chance to retry. Now, health_check_interval is used both to control the periodicity of health checks that may transition the data bridge into disconnected or connecting states, as well as recovering from disconnected.
• #10929 Upgraded Erlang/OTP to 25.3.2-1.
• #10909 Removed the deprecated HTTP APIs for gateways.
• #10933 Added support for configuring TCP keep-alive in MQTT/TCP and MQTT/SSL listeners.
• #10948 Added live_connections field for some HTTP APIs, i.e:
  • /monitor_current, /monitor_current/nodes/{node}
  • /monitor/nodes/{node}, /monitor
  • /node/{node}, /nodes
• #10941 Improved the collection speed of Prometheus metrics when setting prometheus.vm_dist_collector=disabled and metric erlang_vm_statistics_run_queues_length_total is renamed to erlang_vm_statistics_run_queues_length
• #10985 Renamed emqx ctl command cluster_call to conf cluster_sync. The old command cluster_call is still a valid command, but not included in usage info.
• #10988 Improved log security when data bridge creation fails to ensure sensitive data is always obfuscated.
• #10926 Allowed enable as well as enabled as the state flag for listeners. Prior to this change, listener can be enable/disabled by setting the true or false on the enabled config. This is slightly different naming comparing to other state flags in the system. Now the enable flag is added as an alias in listener config.
• #10970 A query_mode parameter has been added to the Kafka producer bridge. This parameter allows you to specify if the bridge should use the asynchronous or synchronous mode when sending data to Kafka. The default is asynchronous mode.
• #10676 Added CLI commands emqx ctl export and emqx ctl import for importing/exporting configuration and user data. This allows exporting configurations and built-in database data from a running EMQX cluster and importing them into the same or another running EMQX cluster.
• #10961 Added support for unlimited max connections for gateway listeners by allowing infinity as a valid value for the max_connections field in the configuration and HTTP API.
• #11019 Improved log security for JWT, now it will be obfuscated before print.
• #11034 Hid the broker config and changed the broker.shared_subscription_strategy to mqtt.shared_subscription_strategy as it belongs to mqtt.
• #11045 The listener's authentication and zone related apis have been officially removed in version 5.1.0.
• #11062 Renamed config log.file.to to log.file.path.
• #10833 Only include enabled authenticators and authorizers in telemetry report, not all of them.

Bug Fixes

• #11018 Fixed multiple issues with the Stomp gateway, including:

  • Fixed an issue where is_superuser was not working correctly.
  • Fixed an issue where the mountpoint was not being removed in message delivery.
  • After a message or subscription request fails, the Stomp client should be disconnected immediately after replying with an ERROR message.

• #11051 Added validation to ensure that certificate depth (listener SSL option) is a non negative integer.

• #10884 Fixed an issue where trying to get rule info or metrics could result in a crash when a node is joining a cluster.

• #10887 Fixed a potential issue where requests to bridges might take a long time to be retried. This only affected low throughput scenarios, where the buffering layer could take a long time to detect connectivity and driver problems.

• #10871 Fixed an issue where the Dashboard shows that the connection still exists after a CoAP connection is disconnected, but deletion and message posting requests do not take effect.

• #10880 Added a new REST API POST /clients/kickout/bulk for kicking out multiple clients in bulk.

• #10923 Fixed a race-condition in channel info registration. Prior to this fix, when system is under heavy load, it might happen that a client is disconnected (or has its session expired) but still can be found in the clients page in dashboard. One of the possible reasons is a race condition fixed in this PR: the connection is killed in the middle of channel data registration.

• #10930 Added a schema validation for duration data type to avoid invalid values. Before this fix, it was possible to use absurd values in the schema that would exceed the system limit, causing a crash.

• #10952 Disallow enabling fail_if_no_peer_cert in listener SSL options if verify = verify_none is set. Setting fail_if_no_peer_cert = true and verify = verify_none caused connection errors due to incompatible options. This fix validates the options when creating or updating a listener to avoid these errors.

  Note: any old listener configuration with fail_if_no_peer_cert = true and verify = verify_none that was previously allowed will fail to load after applying this fix and must be manually fixed.

• #10951 Fixed the issue in MQTT-SN gateway where the mountpoint does not take effect on message publishing.

• #10943 Deprecated UDP mcast mechanism for cluster discovery. This feature has been planed for deprecation since 5.0 mainly due to the lack of actual production use. This feature code is not yet removed in 5.1, but the document interface is demoted.

• #10902 Avoid syncing cluser.hocon file from the nodes running a newer version than the self-node. During cluster rolling upgrade, if an older version node has to restart due to whatever reason, if it copies the cluster.hocon file from a newer version node, it may fail to start. After this fix, the older version node will not copy the cluster.hocon file from a newer, so it will use its own cluster.hocon file to start.

• #10911 The error message and log entry that appear when one tries to create a bridge with a name the exceeds 255 bytes is now easier to understand.

• #10983 Fixed the issue when mqtt clients could not connect over TLS if the listener was configured to use TLS v1.3 only. The problem was that TLS connection was trying to use options incompatible with TLS v1.3.

• #10977 Fixed the delay in updating subscription count metric and corrected configuration issues in Stomp gateway.

• #10950 Fixed the issue where the enable_qos option does not take effect in the MQTT-SN gateway.

• #10994 Redacted proxy-authorization headers as used by HTTP connector to avoid leaking secrets into log files.

• #10996 For any unknown HTTP/API request, the default response is a 404 error rather than the dashboard's index.html.

• #11005 Fixed the issue where the method field cannot be correctly printed in the trace logs of AuthN HTTP.

• #10955 Fixed the issue in MQTT-SN gateway where deleting Predefined Topics configuration does not work.

• #11030 Improved error messages when a validation error occurs while using the Listeners HTTP API.

• #11033 Deprecated the mountpoint field in AuthenticateRequest in ExProto gateway. This field was introduced in e4.x, but in fact, in e5.0 we have provided gateway.exproto.mountpoint for configuration, so there is no need to override it through the Authenticate request.

  Additionally, updates the default value of subscriptions_max, inflight_max, mqueue_max to infinity.

• #11042 Fixed crash on REST API GET /listeners when listener's max_connections is set to a string.

• #11028 Disallowed using multiple TLS versions in the listener config that include tlsv1.3 but exclude tlsv1.2. Using TLS configuration with such version gap caused connection errors. Additionally, drop and log TLS options that are incompatible with the selected TLS version(s).

  Note: any old listener configuration with the version gap described above will fail to load after applying this fix and must be manually fixed.

• #11056 Fixed the issue where newly created listeners sometimes do not start properly. When you delete a system default listener and add a new one named 'default', it will not start correctly.

  • Fixed the bug where configuration failure on certain nodes can cause Dashboard unavailability.

• #11070 Fixed the problem that the cluster.autoclean configuration item does not take effect.

• #11092 and #11100 Fixed problem when replicant nodes were unable to connect to the core node due to timeout in mria_lb:core_nodes() call. Relevant mria pull request: https://github.com/emqx/mria/pull/143

Breaking Changes

Known Issues