emqx/emqx e5.10.2

EMQX Enterprise 5.10.2

on GitHub

Enhancements

Data Integration

• #16183 EMQX now logs messages about dropped expired messages (buffer_worker_dropped_expired_messages ) at the warning level, and throttles such messages per resource ID. This helps identify when specific external resources are not keeping up with incoming message rates, potentially leading to message drops.

• #16206 Added the allow_auto_topic_creation configuration option to the Kafka Producer Connector. When enabled, EMQX allows Kafka to automatically create a topic if it doesn’t exist when a client sends a metadata fetch request.

• #16209 Added support for specifying a custom timestamp column name (ts_column) parameter to GreptimeDB Connector.

Performance

• #15949 Changed the default value of the parse_unit option in listener configuration from chunk to frame. This change can significantly reduce CPU usage when the payload size exceeds the socket buffer (default is 4 KB).

  Note: With parse_unit = frame, if a PUBLISH packet exceeds the maximum allowed size, EMQX will close the connection instead of sending a DISCONNECT packet.

• #16165 Optimized the performance of the GET /clients_v2 API. Previously, when the cluster had around 50,000 clients or more, API calls to retrieve the client list could be extremely slow or even time out.

Bug Fixes

Core MQTT Functionalities

• #15884 Resolve an issue where, in rare cases, the global routing table could indefinitely retain routing information for nodes that had long left the cluster.

• #15518 Resolved a race condition that may lead to accumulating inconsistencies in the routing table and shared subscriptions state in the cluster when a large number of shared subscribers disconnect simultaneously.

Access Control

• #16081 Fixed an issue where clients using extended authentication and memory-based sessions could crash with a session_stepdown_request_exception caused by a calling_self error.

  Example error log

  2025-09-24T07:13:08.973954+08:00 [error] clientid: someclientid, msg: session_stepdown_request_exception, peername: 127.0.0.1:41782, username: admin, error: exit, reason: calling_self, stacktrace: [{gen_server,call,3,[{file,"gen_server.erl"},{line,1222}]},{emqx_cm,request_stepdown,4,[{file,"emqx_cm.erl"},{line,427}]},{emqx_cm,do_takeover_begin,2,[{file,"emqx_cm.erl"},{line,398}]},{emqx_cm,takeover_session,2,[{file,"emqx_cm.erl"},{line,384}]},{emqx_cm,takeover_session_begin,2,[{file,"emqx_cm.erl"},{line,305}]},{emqx_session_mem,open,4,[{file,"emqx_session_mem.erl"},{line,210}]},{emqx_session,open,3,[{file,"emqx_session.erl"},{line,263}]},{emqx_cm,'-open_session/4-fun-1-',4,[{file,"emqx_cm.erl"},{line,290}]},{emqx_cm_locker,trans,2,[{file,"emqx_cm_locker.erl"},{line,32}]},{emqx_channel,post_process_connect,2,[{file,"emqx_channel.erl"},{line,575}]},{emqx_connection,with_channel,3,[{file,"emqx_connection.erl"},{line,852}]},{emqx_connection,process_msg,2,[{file,"emqx_connection.erl"},{line,470}]},{emqx_connection,process_msgs,2,[{file,"emqx_connection.erl"},{line,462}]},{emqx_connection,handle_recv,3,[{file,"emqx_connection.erl"},{line,406}]},{proc_lib,wake_up,3,[{file,"proc_lib.erl"},{line,340}]}], action: {takeover,'begin'}, ...
  

Rule Engine

• #16028 Fixed rule engine jq function memory leak.

  Previously if jq built-in function index is used (e.g. .key | index("name")), it would result in memory leak.

Data Integration

• #16010 Fixed an issue where a Republish Fallback Action could fail with a function_clause error if the originating rule's SQL did not include the metadata field from the rule environment.

  Example error log:

  [error] tag: RESOURCE, msg: failed_to_trigger_fallback_action, reason: {error,function_clause}, fallback_kind: republish, primary_action_resource_id: <<"action:type:name:connector:type:name">>, republish_topic: <<"republish/topic">>
  

• #16043 Improved log details for Kafka data integration when not_all_kafka_partitions_connected event occurs.

• #16046 Fixed a potential out-of-memory (OOM) crash when loading or restarting a configuration containing a Connector with several hundred Actions.

• #16138 Fix a Redis cluster failover issue that could cause the Connector to remain stuck in a "connecting" state.

  Previously, EMQX’s Redis cluster client only refreshed the cluster topology when regular queries (such as GET) failed. However, failures in periodic PING commands did not trigger a refresh. As a result, after a failover, the connector could continue using the outdated cluster topology if no other commands were issued, preventing recovery.

  With this fix, failed PING responses now trigger a cluster topology refresh, ensuring that the connector can detect failovers and recover promptly.

• #16212 Removed Kafka producer linger time when the buffer queue is in memory mode.

Observability

• #15963 Reduced excessive audit log entries generated during looped evaluations in the remote shell (remsh).

• #15967 Fixed an issue where Mnesia transaction blocking during the cleanup of large volumes of audit logs could lead to rapid memory growth.

Breaking Changes

• #16062 Fixed an issue where RocketMQ actions ignored the configured payload template and sent the entire rule output instead.

  If you relied on the previous (incorrect) behavior, you may need to update your payload templates to ensure messages are formatted as expected.