Re: [infinispan-dev] RejectedExecutionException
On 06/12/2010 10:36 PM, Sanne Grinovero wrote:
Hello,
I've noticed the forum post about the RejectedExecutionException
experienced under load [1]. In Hibernate Search we had a similar issue
where the producers where quicker than the consumption of tasks; while
I agree about defining a larger queue it's still possible to
experience the error.
What we did there is to customize the ThreadPool factory to have the
caller block waiting for space in the queue when it's full [2].
This seems to me a sane approach, not sure why there's no such policy
by default in j.u.concurrent. am I missing something obvious?
I have implemented this same policy in the same way, however I abandoned
this solution when I discovered subtle problems which occur in certain
cases where there's work in the queue and suddenly no threads to run the
work, or work is enqueued and the thread pool is below the max size, but
the work sits in queue because no new thread is started to process it, or
tasks are accepted after the thread pool is shut down (this is a problem if
you take acceptance of a task to be any sort of guarantee that it will be
executed; granted I see that in your example the ultimate fallback policy
is to discard the task in case of interruption, a policy I happen to
disagree with because of the indeterminate results that it may cause).
In the end, I decided that TPE was just not designed to solve this problem
in this way, so for JBossAS 6+ I ended up writing an alternative thread
pool implementation for the specific case where you want the caller to block.
--
- DML ☍