Unbalanced total requests of execute thread

Question

Hi,
I am in wls7.0sp1 running on win2k with 4 processors. when I monitor the managed
servers, I found out the total requests of the thread in default thread queue
varies a lot. the The servers were started couples days ago, the throughput are
around 200,000.
First, Socket Reader. There 2 of them have over 5000 requests, and couple less
than 100, and the rest just have 1 request.
Second, there is a thread always has "Read Multicast Msg Fragment" as the request,
my guessing is that this thread is dealing with the multicast, but it only has
less than 20 total requests. But from the monitor - cluster I can the fragment
received is over 50000.
Third, the rest of the threads are used by application. I have only one web application,
no stand alone app. so the requests are all from servelt/jsp. some threads have
more than 50000 requests, some only have 2 digits. one of the servers has some
threads have 0 requests.
why the usage of thread are not balanced?
Thanks

Answer 1

See answers inline
--dejan
Jen wrote:
what's the algorithm to hand the request to the threads? some are busy some are
starving.
I don't know what the algorithm for the dispatching of the requests is
-- you can ask someone from BEA about it.
Why do you think that some of the threads are starving? All idle threads
should be waiting on a lock and this only means that the are not
currently executing any requests. When a thread is waiting for a lock it
cannot be starving since it is not even scheduled for execution.
>
If i start my own threads on start up, and calls the ejb in the threads, does
the ejb be in my thread or use the default thread?
It's called in your thread. Although on the server BEA does not
recommend doing that, but we're using it and haven't seen any issues
with that.
"Deyan D. Bektchiev" <[email protected]> wrote:
The threads in the execute queue only wake up if there is a request that
has to be processed and until the thread is to process a request it is
not even scheduled for execution so there are no unnecessary context
switches.
The threads do consume some memory and the JVM has some overhead
associated with the number of threads to manage but this is probably
not
too much if you are creating a reasonable number of threads (we've run
in some cases with up to 200 threads for I/O bound applications).
Regards,
Dejan
Jen wrote:
If it always use that has been used thread, then if I add more threads
to the execute
queue it should not add extra context switch and decrease the performance,
that
way I won't need to worry about there is not enough threads during the
peak time.
"Deyan D. Bektchiev" <[email protected]> wrote:
This just means that your server is not under very heavy load and it's
just using some of its resources.
What advantages do you see in the balancing of the requests between
different threads in the same JVM?
If you had a cluster and the number of requests was not balanced on
a
server by server basis then it might be something to concerned of.
Dejan
Jen wrote:
Hi,
I am in wls7.0sp1 running on win2k with 4 processors. when I monitor
the managed
servers, I found out the total requests of the thread in default thread
queue
varies a lot. the The servers were started couples days ago, the throughput
are
around 200,000.
First, Socket Reader. There 2 of them have over 5000 requests, and
couple
less
than 100, and the rest just have 1 request.
Second, there is a thread always has "Read Multicast Msg Fragment"
as
the request,
my guessing is that this thread is dealing with the multicast, but
it
only has
less than 20 total requests. But from the monitor - cluster I can
the
fragment
received is over 50000.
Third, the rest of the threads are used by application. I have only
one web application,
no stand alone app. so the requests are all from servelt/jsp. some
threads
have
more than 50000 requests, some only have 2 digits. one of the servers
has some
threads have 0 requests.
why the usage of thread are not balanced?
Thanks