Queues

Queues

Message queues receive, hold, and deliver messages. If an operation is too slow to perform inline, you can use a message queue with the following workflow:

• An application publishes a job to the queue, then notifies the user of job status
• A worker picks up the job from the queue, processes it, then signals the job is complete

The user is not blocked and the job is processed in the background. During this time, the client might optionally do a small amount of processing to make it seem like the task has completed. For example, if posting a tweet, the tweet could be instantly posted to your timeline, but it could take some time before your tweet is actually delivered to all of your followers.

Benefits

• Better Performance – Producers can add requests to the queue without waiting for them to be processed.
• Increased Reliability – Queues make your data persistent, and reduce the errors that happen when different parts of your system go offline.
• Granular Scalability – Message queues make it possible to scale precisely where you need to.
• Simplifed Decoupling

Task queues

Tasks queues receive tasks and their related data, runs them, then delivers their results. They can support scheduling and can be used to run computationally-intensive jobs in the background.

See also

• Limit message queues Reliability