Re: [infinispan-dev] design for cluster events (wiki page)
On Oct 31, 2013, at 7:10 AM, Bela Ban <bban(a)redhat.com> wrote:
Just to clarify, can you comment on whether the statements below are
true ?
#1 When mode=repl is used, the event itself is never broadcast; it is
always local and no communication is needed
yes. for replicated caches we should handle this as a local listener.
#2 when mode=dist, is the event broadcast synchronously or
asynchronously, can this be configured ? I think it doesn't make sense
to broadcast the event synchronously in dist-async, for instance.
there are two levels of asynchronicity:
- the cluster is configured to be asyn
- the listeners can be configured to be notified in an async thread (@Listener
async=true)
In both situations the notification from the event should be broadcasted asynchronously
Regarding #2: if this mechanism is used unwisely, a user can destroy all
the advantages (perf) brought by DIST by causing a broadcast for every
update. Is there anything to prevent this (e.g. a sanity check at startup) ?
I guess we should expose a "filtering rate" statistics on every filter and log
INFO if the filtering rate is very low. That should at least give an idea on the amount of
traffic caused by the listener.
Thank you Bela, I'll update the doc with your suggestions.
Cheers,
--
Mircea Markus
Infinispan lead (www.infinispan.org)