RabbitMQ之tutorial-7
RabbitMQ之tutorial-7
Tutorial Seven
https://www.rabbitmq.com/tutorials/tutorial-seven-java.html
Publisher confirms are a RabbitMQ extension to implement reliable publishing.
confirmSelect
Strategy #1: Publishing Messages Individually
it significantly slows down publishing,as the confirmation of a message blocks the publishing of all subsequent messages.
Strategy #2: Publishing Messages in Batches
One drawback is that we do not know exactly what went wrong in case of failure, so we may have to keep a whole batch in memory to log something meaningul or to re-publish the messages.
Strategy #3: Handling Publisher Confirms Asynchronously
2 callbacks: one for confirmed messages and one for nack-ed messages
sequence number: a number that identifies the confirmed or nack-ed message. We will see shortly how to correlate it with the published message.
multiple: this is a boolean value. If false, only one message is confirmed/nack-ed, if true, all messages with a lower or equal sequence number are confirmed/nack-ed.
correlate messages:
- provide a way to correlate the publishing sequence number with a message.
- register a confirm listener on the channel to be notified when publisher acks/nacks arrive to perform the appropriate actions, like logging or re-publishing a nack-ed message. The sequence-number-to-message correlation mechanism may also require some cleaning during this step.
- track the publishing sequence number before publishing a message.
