[jboss-user] [JBoss Cache Development] Document updated/added: "Extracting jbosscache async listener stats"
User development,
The document "Extracting jbosscache async listener stats", was updated Feb 9,
2010
by Daniel Cullender.
To view the document, visit:
http://community.jboss.org/docs/DOC-14766#cf
Document:
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We are currently using jbosscache core 3.2.1.GA and currently push literally millions of
records into it. We have asynchronous listeners processing the data as it is put into the
cache.
The problem is that the listeners cannot process the data quickly enough and this causes a
backlog in the async queue size (which is set to a number in the millions). Increasing the
Async pool size over 250 does not help either based on the various (but necessary) locks
we have in place.
In order to successfully manage the backlog, we needed to monitor the cache's Async
Listener's Queue size to see when it grows to large. Unfortunately, we could not find
a way to access these type of stats from the cache, so we downloaded the source code and
exposed these stats ourselves.
*Code Modifications*
1. We created a new immutable VO called org.jboss.cache.notifications.NotifierRuntime
which holds the various statistics relating to the async listener queue and pool
2. in the org.jboss.cache.notifications.NotifierImpl class, keep a reference to the
ThreadPoolExecutor which the BoundedExecutor assigns to the asyncProcessor since this
contains all the information you need to extract the queue size (along with other useful
stats)
3. expose a method on the org.jboss.cache.notifications.Notifier interface and the
org.jboss.cache.Cache interface to expose a method which returns this immutable object
(org.jboss.cache.notifications.NotifierRuntime) which is populated with delicious data
(Our object contains minimal info, but could easily be extended to expose a whole lot more
data).
These statistics have helped us manage the backlog and keep our application afloat.
I have attached the source code and built jar for anyone who has a similar requirement.
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