TTL - Message Expiry check on the queue..

giri

If TTL on a message is set to 180secs (say), wondering when the expiry is checked and removal of expired events occur?
Just curious how the following scenarios are handled:
a) If DMQ is enabled, the dequeue from current queue and enqueue on the DMQ has to occur at the exact time when the message expired, right?
b) If no DMQ, for a durable queue how long will the messages be held in the queue? The expiry check is automatic (back-ground ops) or triggered by some action (like request)?

TomF

Hi @giri,

Expiry checking is an asynchronous, background process, so it isn't triggered by anything external, such as a bind to a queue or an admin command. That should answer b).

For a), it's important to remember Solace's spool based architecture: the message data is held in an abstracted view of persistent storage called "the spool." Queues are a view of the spool: messages in a queue are actually stored as references to the original message. So when a message is "moved" from a queue to a DMQ, what's actually happening is the reference is deleted from the original queue and added to the DMQ. For our purposes, that's instantaneous.

Hope that helps!

TomF

Hi @giri,

Expiry checking is an asynchronous, background process, so it isn't triggered by anything external, such as a bind to a queue or an admin command. That should answer b).

For a), it's important to remember Solace's spool based architecture: the message data is held in an abstracted view of persistent storage called "the spool." Queues are a view of the spool: messages in a queue are actually stored as references to the original message. So when a message is "moved" from a queue to a DMQ, what's actually happening is the reference is deleted from the original queue and added to the DMQ. For our purposes, that's instantaneous.

Hope that helps!

giri

Thanks Tom, as always pretty explanative 👍