Manage message queues

You can manage message queues from the command line using cron jobs or an external process manager to ensure that consumers are retrieving messages.

Process management

Cron jobs are the default mechanism to restart consumers. Processes started by cron consume the specified number of messages and then terminate. Rerunning cron restarts the consumer.

The following example shows the crontab configuration for running consumers:

/app/code/Magento/MessageQueue/etc/crontab.xml

...
<job name="consumers_runner" instance="Magento\MessageQueue\Model\Cron\ConsumersRunner" method="run">
    <schedule>* * * * *</schedule>
</job>
...

You can also use a process manager such as Supervisor to monitor the status of processes. The manager can use the command line to restart the processes as needed.

Configuration

Behavior by default

• Cron job consumers_runner is enabled
• Cron job consumers_runner runs all defined consumers
• Each consumer processes 10000 messages and then terminates

Specific configuration

Edit the /app/etc/env.php file to configure the cron job consumers_runner.

...
    'cron_consumers_runner' => [
        'cron_run' => false,
        'max_messages' => 20000,
        'consumers' => [
            'consumer1',
            'consumer2',
        ],
        'multiple_processes' => [
            'consumer1' => 4
        ]
    ],
...

• cron_run - A boolean value that enables or disables the consumers_runner cron job (default = true).

• max_messages - The maximum number of messages each consumer must process before terminating (default = 10000). Although we do not recommend it, you can use 0 to prevent the consumer from terminating. See consumers_wait_for_messages to configure how consumers process messages from the message queue.

• consumers - An array of strings specifying which consumers to run. An empty array runs all consumers.

• multiple_processes - An array of key-value pairs specifying which consumer to run in how many processes. Supported in Commerce 2.4.4 or greater.

  INFO

  It is not recommended to run multiple consumers on a MySQL-operated queue. See Change message queue from MySQL to AMQP for more information.

  INFO

  If your Adobe Commerce store is hosted on the Cloud platform, use the CONSUMERS_WAIT_FOR_MAX_MESSAGES to configure how consumers process messages from the message queue.

See Start message queue consumers.