From another thread Re: one word syncronize once more, new thread
created as I also don't believe the issues are related.
Greg Ames wrote:
if you have a hung server, I would do some more diagnosis and not get
sidetracked by MRPC. have you looked for unusual messages in the error
log, especially messages that mention MaxClients? have you gotten
samples of the server-status page with ExtendedStatus on? do you see a
pattern with certain URLs that hang and others that do not? are small
local static files always served quickly?
The hung apache runtime always occur after the leader apache process has
been given its signal to terminate. So talking in terms of what web
pages it serves makes no sense, since it has already shutdown all
further webpage processing. The fatal bug is that the apache leader
process does not terminate in good time and remains running. I believe
it also hang onto the bound listerning tcp sockets as well, obvious a
kill -9 gets rid of it.
I'm not sure without any extra information if this list will be able to
assist in the matter, maybe there is someway to have apache emit debug
logging information to stdout/stderr which I can capture to see where in
apache it is hung up and what it is waiting for, maybe a sledgehammer
approach of using a SIGALRM and new handler to be put in place as soon
as apache begins its shutdown. This new handler will raise a SIGKILL on
itself should it go off. Its unlikely I'd have chance to investigate
this matter in the short term anyway.
I was just using the previous thread as an example to get insight into
what actual real life problems may result from lost increment/decrements
due to SMP concurrent issues.
Darryl
