Amazon SQS Delay Queues
Delay queues let you postpone the delivery of new messages to a queue for a number
of seconds. If you create a delay queue,
any messages that you send to the queue remain invisible to consumers for the duration
of the delay period. The default (minimum) delay for a queue is 0 seconds. The maximum
is 15 minutes. For information about configuring delay queues using the
AWS Management Console or the AWS SDK for Java (and the SetQueueAttributes
action), see Configuring an Amazon SQS Delay Queue.
Note
For standard queues, the per-queue delay setting is not retroactive—changing the setting doesn't affect the delay of messages already in the queue.
For FIFO queues, the per-queue delay setting is retroactive—changing the setting affects the delay of messages already in the queue.
Delay queues are similar to visibility timeouts because both features make messages unavailable to consumers for a specific period of time. The difference between the two is that, for delay queues, a message is hidden when it is first added to queue, whereas for visibility timeouts a message is hidden only after it is consumed from the queue. The following diagram illustrates the relationship between delay queues and visibility timeouts.
To set delay seconds on individual messages, rather than on an
entire queue, use message timers to allow
Amazon SQS to use the message timer's DelaySeconds value instead of the delay
queue's DelaySeconds value.
