EMQ X 4.2-rc.1 is released now, it mainly includes the following changes:

emqx

Enhancements:

• Allow multiple MQTT messages to be included in a WebSocket message to improve efficiency, or it can be configured to include only one MQTT message to be compatible with some clients

  Github Issue: emqx#3324

  Github PR: emqx#3673

• Allow independent configuration of topic rewrite rules for publishing and subscription

  Github PR: emqx#3676

Bug fixes:

• Fix the issue of abnormal memory growth caused by the topic metrics feature

  Github PR: emqx#3679

emqx-rel

Bug fixes:

• Fix the issue that losing old configuration after hot upgrade

  Github PR: emqx-rel#578

emqx-bridge-mqtt

Enhancements:

• Provide ${node} placeholder for clientid configuration item

  Github PR: emqx-bridge-mqtt#100

emqx-telemetry

Enhancements:

• The telemetry feature is officially launched. This feature is used to help us improve our products and is enabled by default. This feature does not collect any personally identifiable information. Users can query the data we report through the open API

  Github PR: emqx-telemetry#1

emqx-exproto

Bug fixes:

• Fix some bugs

  Github PR: emqx-exproto#11

emqx-management

Bug fixes:

• Fix the issue that RPM/Deb package cannot export data

  Github PR: emqx-management#257