[rabbitmq-discuss] Queue Ordering after restart

[John DeTreville]

On Dec 1, 2010, at 2:51 PM, rathi <riteshrathi at gmail.com<mailto:riteshrathi at gmail.com>> wrote:

From: rathi <riteshrathi at gmail.com<mailto:riteshrathi at gmail.com>>
Date: December 1, 2010 7:41:53 AM PST
To: rabbitmq <rabbitmq-discuss at lists.rabbitmq.com<mailto:rabbitmq-discuss at lists.rabbitmq.com>>
Subject: [rabbitmq-discuss] Queue Ordering after restart

I have only one consumer which should process messages in the order they are published. If my consumer gets M1 and crashes without acknowledging M1, then when I restart my consumer I want to process messages in the same order as they were published. Can this be achieved ?

I should first point out that I work in RabbitMQ's Pacific Rim office, 8 time zones away from London. I answer questions in the middle of their night. I may be trading off accuracy for promptness.

That said, I believe you cannot. I believe that if your application crashes (or closes its connection) without acknowledging a message, and the queue is persistent, then the message may later appear out of order.

More generally, if your application crashes K times without acknowledging messages, then those K messages may later appear out of order.

Cheers,
John