All stable feature flags must be enabled after completing an upgrade
Article ID: 395469
Updated On:
Products
Issue/Introduction
After upgrading RabbitMQ cluster from version 3.13.7 to 4.0.7, a yellow notification appears on the management UI, stating: "All stable feature flags must be enabled after completing an upgrade." Following this, the rabbitmq_4.0.0 feature flag is observed to be disabled post-upgrade.
Environment
RabbitMQ version: 4.X
Cause
RabbitMQ 4.0 introduces a new feature flag that controls multiple features and changes, including new quorum queue features and the AMQP-1.0 flow control mechanism. When you upgrade from RabbitMQ 3.x to 4.0, the system will run in a backwards-compatible mode until the rabbitmq_4.0.0 feature flag is explicitly enabled. As a result, the feature flag remains disabled after the upgrade and must be manually enabled.
Resolution
To resolve the issue and enable the rabbitmq_4.0.0 feature flag:
1. Verify the current feature flag status:
rabbitmqctl list_feature_flags
2. Then enable the rabbitmq_4.0.0 feature flag:
rabbitmqctl set_feature_flag rabbitmq_4.0.0 true
Or you can toggle this in the management UI, by selecting - "Enable"
3. Restart each RabbitMQ node one at a time to apply the changes. Ensure that you do not restart all nodes simultaneously to avoid downtime.
4. Verify that the flag is enabled after restarting each node by running the following command on the restarted node:
rabbitmqctl list_feature_flags
Additional Information
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