Carsten,
I agree self-tuning single threadpool would be a very interesting
implementation. We should be able to adjust the maximum threads for a
pool over a given interval. I think making it a single thread pool
would be the tricky part since I think we could deadlock if the entire
active threadpool was filled with async threads. But perhaps a timeout
could be set to ensure that some of them get kicked out after a given
amount of time. I'll do some more research on that but in the mean time
I'll submit a jira for the config option.
- Bob
On 8/28/2014 8:25 AM, Carsten Ziegeler wrote:
Hi Bob,
this sounds good to me, however it would be even better if the event admin
could find out the ratio and adjust it accordingly. I'm not against making
this configurable, but it might be hard to know the good value upfront.
As a general node, it would be great, if we could simply have a single
thread pool :)
But +1 for a patch in any case.
Carsten
2014-08-28 15:00 GMT+02:00 Bob Paulin <[email protected]>:
Hi,
I'd like to propose adding an additional configuration variable to Event
Admin that controls the sync to async thread ratio. Currently the code
sets an intelligent default that sets the async threads at 50% of the sync
threads as long as there are more than 5 total sync threads.
final int asyncThreadPoolSize = m_threadPoolSize > 5 ? m_threadPoolSize /
2 : 2;
This assumes an even split between post and send operations. However this
is not the case with many applications leaning heavily one way or the
other. I'd like to replace the above code with:
final int asyncThreadPoolSize = m_threadPoolSize > 5 ?
Math.floor(m_threadPoolSize * m_asyncToSyncThreadRatio) : 2;
With m_asyncToSyncThreadRatio defaulting to 0.5. This leaves the
intelligent defaults but allows the admin to tune the application based on
the application usage. This tuning can show significant performance
improvements. From the EventAdmin StressTestIT:
Scenerio 100% Async events
Events sent 1050000
Producer Threads 15
@ 50% async to sync ratio
PAXEXAM-PROBE-8762bbe7-91d9-4ff1-8562-38096af676da[org.
apache.felix.eventadmin.ittests.StressTestIT] : Finished tests, received
1050000 events in 6551ms
@ 100% async to sync ratio
PAXEXAM-PROBE-02e70ff6-36ff-4bed-ab00-f2bcb9440109[org.
apache.felix.eventadmin.ittests.StressTestIT] : Finished tests, received
1050000 events in 4871ms
Thoughts? Happy to submit a patch if there are no concerns.
- Bob Paulin
