RabbitMQ - Python/Pika 如何知道队列是否为空？

Question

My idea is also described here if I express myself incorrectly ( Send images with their names in one message - RabbitMQ (Python 3.X) )

I currently have a problem with RabbitMQ --->

I made a working queue on which several consumers work at the same time, it is a containerized image processing that gives a str output with the requested information.

The results must be sent on another queue when the processing is finished, but how do I know if the queue containing the images is empty and there is no more work to do? I would like to know if a command like "if the queue is empty, then send the results..." to say it roughly.

Thank you for your time, have a good day.

Answer 1

You can do a passive declare of the queue to get the count of messages, but that may not be reliable as the count returned does not include messages in the "unacked" state. You could query the queue's counts via the HTTP API.

Or, whatever application publishes the images could send a "no more images" message to indicate no more work to do. The consumer that receives that message could then query the HTTP API to confirm that no messages are in the Ready or Unacked state, then send the results to the next queue.

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