I've walked through the code to forward expiration actions to async
event listeners & don't see how to apply it to removal of queue entries
for WAN. The current implementation just queues the expiration
actions. If we wanted to remove any queued events associated with the
expired region entry we'd have to scan the whole queue, which would be
too slow if we're overflowing the queue to disk.
I've also walked through the conflation code. It applies only to the
current batch being processed by the gateway sender. The data structure
used to perform conflation is just a Map that is created in the sender's
batch processing method and then thrown away.
On 3/20/19 11:15 AM, Dan Smith wrote:
2) The developer wants to replicate _state_. This means that implicit
state changes (expiration or eviction w/ destroy) could allow us to
optimize the queue size. This is very similar to conflation, just a
different kind of optimization.
For this second case, does it make sense to allow the user to specify a
different TTL than the underlying region? It seems like what the user
wants is to not replicate stale data and having an extra TTL attribute
would just be another value to mis-configure. What do you think about just
providing a boolean flag?
This kinda jogged my memory. AsyncEventQueues actually *do* have a boolean
flag to allow you to forward expiration events to the queue. I have no idea
how this interacts with conflation though -
https://geode.apache.org/releases/latest/javadoc/org/apache/geode/cache/asyncqueue/AsyncEventQueueFactory.html#setForwardExpirationDestroy-boolean-
