RabbitMQ- Zed.CRITICAL- PhpAmqpLib\Exception\AMQPChannelClosedException - Channel connection is closed

Description

Events are not consumed or are consumed slowly. In RabbitMQ exception.log, the following exception can be found:

Zed.CRITICAL: PhpAmqpLib\Exception\AMQPChannelClosedException - Channel connection is closed.

Cause

The exact reason for the error is unknown, but we’ve noticed that it occurs predominantly in large Spryker environments with many product updates. We continue to explore the root cause.

Solution

We have discovered two options that helped to resolve the error:

1. Implementing RabbitMQ lazy queues One possible solution can be implementing RabbitMQ lazy queues to reduce RAM usage. This is already implemented for PaaS customers. Configuring RabbitMQ to put messages on disk and load them into memory only when they are needed (lazy queuing) can help. For instructions on how to do this, see the CloudAMQ article Stopping the stampeding herd problem with lazy queues.

2. Adjusting CHUNK_SIZE Using smaller chunk sizes for export and storage sync in RabbitMQ might also help to alleviate the issue. Include the following values in the config file used:

$config[SynchronizationConstants::EXPORT_MESSAGE_CHUNK_SIZE] = 200;
$config[SynchronizationConstants::DEFAULT_SYNC_STORAGE_QUEUE_MESSAGE_CHUNK_SIZE] = 200;
$config[SynchronizationConstants::DEFAULT_SYNC_SEARCH_QUEUE_MESSAGE_CHUNK_SIZE] = 200;
$config[EventConstants::EVENT_CHUNK] = 200;