Message Queue

What is the Message Queue

Shopware uses the Symfony Messenger component and Enqueue to handle asynchronous messages. This allows tasks to be processed in the background. Thus, tasks can be processed independently of timeouts or system crashes. By default, tasks in Shopware are stored in the database and processed via the browser, as long as you are logged into the administration. This is a simple and fast method for the development process, but not recommended for production systems. With multiple users logged into the administration, this can lead to high CPU load and interfere with the smooth execution of PHP FPM.

Message Queue on production systems

On a productive system, the message queue should be processed via the CLI instead of the browser in the administration (Admin worker). This way, tasks are also completed when no one is logged into the administration and high CPU load due to multiple users in the admin is also avoided. Furthermore you can change the transport to another system like RabbitMQ for example. This would on the one hand relieve the database and on the other hand use a much more specialized service for handling message queues. The following are examples of the steps needed. It's recommended to run one or more messenger:consume-workers. To automatically start the processes again after they stopped because of exceeding the given limits you can use a process control system like systemd or supervisor. Alternatively you can configure a cron job that runs the command periodically. Please note: Using cron jobs won't take care of maximum running worker, like supervisor can do. They don't wait for another worker to stop. So there is a risk starting an unwanted amount of workers when you have messages running longer than the set time-limit. If the time-limit has been exceeded worker will wait for the current message being finished.
Find here the docs of Symfony: https://symfony.com/doc/current/messenger.html#deploying-to-production
It is recommended to use a third party message queue to support multiple consumers and / or a greater amount of data to index.

Consuming Messages

The recommended method for consuming messages is using the cli worker.

Cli worker

You can configure the command just to run a certain amount of time and to stop if it exceeds a certain memory limit like:
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bin/console messenger:consume default --time-limit=60 --memory-limit=128M
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For more information about the command and its configuration use the -h option:
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bin/console messenger:consume -h
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Admin worker

If you have configured the cli-worker, you should turn off the admin worker in the shopware configuration file, therefore create or edit the configuration shopware.yaml.
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# config/packages/shopware.yaml
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shopware:
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admin_worker:
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enable_admin_worker: false
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The admin-worker, if used, can be configured in the general shopware.yml configuration. If you want to use the admin worker you have to specify each transport, that previously was configured. The poll interval is the time in seconds that the admin-worker polls messages from the queue. After the poll-interval is over the request terminates and the administration initiates a new request.
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# config/packages/shopware.yaml
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shopware:
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admin_worker:
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enable_admin_worker: true
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poll_interval: 30
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transports: ["default"]
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systemd example

We assume the services to be called shopware_consumer.
Create a new file /etc/systemd/system/[email protected]
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[Unit]
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Description=Shopware Message Queue Consumer, instance %i
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PartOf=shopware_consumer.target
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​
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[Service]
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Type=simple
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User=www-data # Change this to webservers user name
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Restart=always
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RestartSec=always
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# Change the path to your shop path
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ExecStart=php /var/www/html/bin/console messenger:consume --time-limit=60 --memory-limit=512M
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​
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[Install]
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WantedBy=shopware_consumer.target
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Create a new file /etc/systemd/system/shopware_consumer.target
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[Install]
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WantedBy=multi-user.target
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​
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[Unit]
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Description=shopware_consumer service
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Enable multiple instances. Example for three instances: systemctl enable [email protected]{1..3}.service
Enable the dummy target: systemctl enable shopware_consumer.target
At the end start the services: systemctl start shopware_consumer.target

Sending Mails over the Message Queue

By default Shopware sends the mails synchronously. Since this can affect the page speed, you can switch it to use the Message Queue with a small configuration change.
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# config/packages/framework.yaml
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framework:
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mailer:
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message_bus: 'messenger.default_bus'
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Transport: RabbitMQ example

In this example we replace the standard transport, which stores the messages in the database, with RabbitMQ. Of course, other transports can be used as well. A detailed documentation of the parameters and possibilities can be found in the enqueue symfony documentation. In the following I assume that RabbitMQ is installed and started. Furthermore, a queue, here called shopware-queue, should be created inside RabbitMQ. The only thing left is to tell shopware about the new transport. Therefore we edit/create the configuration file enqueue.yaml with the following content:
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# config/packages/enqueue.yaml
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enqueue:
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rabbitmq:
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transport:
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dsn: "amqp://guest:[email protected]:5672/%2F?connection_timeout=1000&heartbeat=100"
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client: ~
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Be sure to replace the login credentials, host and port with your correct parameters in the connection string. And now we activate that transport and replace the default one of shopware. This can be done by editing/creating the file framework.yaml.
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# config/packages/framework.yaml
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framework:
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messenger:
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transports:
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default:
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dsn: "enqueue://rabbitmq?queue[name]=shopware-queue"
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Notice that shopware-queue is the name of the previously created queue in RabbitMQ. Also rabbitmq matches the name of the new transport in the previously created enqueue.yaml.
Last modified 3mo ago