[Notice] DMS for RabbitMQ Will Discontinue the Delayed Message Plug-in

Affected Regions

All regions

Reason

If the delayed message plug-in is enabled for an instance, delayed messages may accumulate and raise the following risks:

• The delayed messages are stored in the Mnesia memory database. If many messages (from 10 thousands to millions) are stacked, the high watermark of the memory may block message production. For details, see Limitations.
• The more stacked delayed messages, the longer DMS takes to start a RabbitMQ node. In this case, services may not be restored in time after a node restarts.
• Delayed messages are stored in single replicas. If a replica is restarted, delayed messages on it cannot be consumed.

Mitigation

For instances with the delayed message plug-in enabled, configure memory usage alarms for every node. For example, set the alarm threshold to 30% if the high watermark is triggered when the memory usage reaches 40%. If an alarm is triggered, increase the broker flavor before the high watermark is reached. If the high watermark is already reached, accelerate message consumption.

Alternative

• If your RabbitMQ instances have not enabled the delayed message plug-in and you need to use the function, use delayed messages of RabbitMQ AMQP-0-9-1 or scheduled/delayed messages of DMS for RocketMQ instead.
• If your RabbitMQ instances have enabled the delay message plug-in, migrate your services that are using delayed messages to DMS for RabbitMQ AMQP-0-9-1 or DMS for RocketMQ. Then, disable the delayed message plug-in on your RabbitMQ instances. Migrate message consumption first and then the production, so services will not be affected.

Impact

• The delayed message plug-in will no longer be displayed for instances with this plug-in disabled.
• The delayed message plug-in is still available for instances with this plug-in enabled, but will no longer be displayed if you disable it on the console.

If you have any questions, please submit a service ticket.