Option A is correct because setting the consumers_wait_for_max_messages variable true in the deployment stage is the best way to meet the requirement. This variablecontrols whether the queue consumers should wait for a maximum number of messages to process before terminating. If this variable is set to true, the consumers will not terminate after processing the available messages in the queue, but will wait until they reach the max_messages limit or the cron job timeout. This way, the consumers can keep the TCP connections open and avoid delays in processing messages1.

Option B is incorrect because increasing the multiple_process limit to spawn more processes for each consumer will not solve the issue of queue consumers closing TCP connections too often. The multiple_process limit determines how many parallel processes can be run for each consumer. Increasing this limit may improve the throughput of message processing, but it will also consume more server resources and may cause conflicts or errors. Moreover, it will not prevent the consumers from terminating after processing the available messages in the queue2.

Option C is incorrect because changing the max_messages from 10,000 to 1,000 for CRON_CONSUMERS_RUNNER variable will worsen the issue of queue consumers closing TCP connections too often. The max_messages variable defines how many messages each consumer should process before terminating. Decreasing this variable will make the consumers terminate more frequently, which will result in more TCP connections being closed and reopened. This will increase the delays in processing messages3.

References:

1: Configure message queues | Adobe Commerce Developer Guide

2: Configure message queues | Adobe Commerce Developer Guide

3: Configure message queues | Adobe Commerce Developer Guide