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.
________________
