ok fair point, but again the limit of "app deadlock" and "load induced
timeouts" should be very cleanly separated for the simple reason that in the
first case the blame falls on the app developer in the second case the blame
will fall on us "hey jboss starts "exception throwing" when under load"...
not good right?
marc
|-----Original Message-----
|From: [EMAIL PROTECTED]
|[mailto:[EMAIL PROTECTED]]On Behalf Of Sebastien Alborini
|Sent: Friday, October 20, 2000 9:03 AM
|To: jBoss Developer
|Subject: Re: [jBoss-Dev] time-outs (what is their *real* use)
|
|
|Hi,
|
|Another timeout use: in case of an application deadlock (not our fault),
|tx timeout seems to be the only "clean" way out.
|
|Sebastien
|
|marc fleury wrote:
|>
|> So I see 2 usages of time out...
|>
|> one is a "time-out" because someone went to lunch and we don't
|want to tie
|> up resources on the server, passivation won't do since we are in a
|> transaction.
|>
|> the other one we see under test, is that under very heavy load (we are
|> doing the tests right now), like loads that puts a good lunix
|machine under
|> x5 CPU load, the server time-outs the transactions after awhile.
|>
|> BTW sebastien found a fix for that "timeout bug" that I
|described before and
|> it now works, the server doesn't lock at all. it runs *very* well.
|>
|> So now under very heavy load it throws many exceptions (timeout
|exceptions)
|> but it goes on very happily.
|>
|> My question is this
|> 1- can't we put a time out at 1hour or so. The reason is very simple. I
|> was always impressed by the "stability" of linux... ie. under very heavy
|> load, it swaps and goes slow and what not but it carries on and finishes.
|> If we put one hour, under the loads described (hey even the big
|SAP install
|> I know of don't go up to 1000 concurent clients all on the SAME
|instance),
|> then the server will surely take the time to answer (it will be
|slow) but at
|> least IT WON"T THROW EXCEPTIONS on timeouts.
|> 2- Ole, we have tried to change the time out time on your
|timeout factories,
|> but with no success whatsoever... how do you do it?????
|> 3- In case we go with 1, then the "load" should be done in a
|> "MetricsInterceptor" that can provide some feedback on the time
|it takes to
|> complete a call, the number of beans in the container, the
|number of threads
|> that are in etc etc... we can then provide an MBean that gives all that
|> information. (time in-time out etc etc)... hey the famous group
|77 s'got to
|> be good for something...
|>
|> open to opinions...
|>
|> stability? metrics? exceptions?
|>
|> my vote is clear: percieved stability is very important... and
|the fact is
|> that the container is super-stable even under very heavy load...
|so why give
|> a bad impression on timeout exceptions, people will see that it
|is slow and
|> that is all the information they need, or eventually a "mail"
|from the new
|> interceptor that says "buy some more hardware dude!" but not these nasty
|> "timeout exceptions".... I don't know, what do you think?
|>
|> regards
|>
|> ________________
|> Marc Fleury, PhD
|> CTO, Telkel Inc.
|> ________________
|
|
