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Thread: Server Overload

Server Overload

From
"Arthur M. Kang"
Date:
I've seen brief posts regarding server loads, distrubution for heavy loads,
etc, but don't recall if there were any solutions...

Anyways...We are running a Postgres DB against multiple frontend
webservers.  For most of the time, everything runs fine.  Then, all of a
sudden, everything will start to go all funky.  Crashing...Errors...Etc...

When I log onto the DB server and try to do anything, I get "Too many open
files in system."  ulimit is set to unlimited and there is PLENTY of FREE
memory.
I shut down one of the frontend servers to clear some connections to the DB
and then start it back up and everything seems to be back to normal.

Has anyone experienced anything similar?  Does anyone have any suggestions
on what I could try to do to rectify this problem?

Any comments and/or suggestions are much appreciated!

Thanks.

Arthur

Re: Server Overload

From
Tom Lane
Date:
"Arthur M. Kang" <arthur@levelogic.com> writes:
> When I log onto the DB server and try to do anything, I get "Too many open
> files in system."

Sounds like you need to regenerate your kernel with larger NFILE and/or
NINODE parameters.  Can't give you details about how to do this since
every Unix platform has a different way to do it, but consult your
sysadmin documentation.

            regards, tom lane

Re: Server Overload

From
"Steve Wolfe"
Date:
> I've seen brief posts regarding server loads, distrubution for heavy
loads,
> etc, but don't recall if there were any solutions...
>
> Anyways...We are running a Postgres DB against multiple frontend
> webservers.  For most of the time, everything runs fine.  Then, all of a
> sudden, everything will start to go all funky.  Crashing...Errors...Etc...
>
> When I log onto the DB server and try to do anything, I get "Too many open
> files in system."  ulimit is set to unlimited and there is PLENTY of FREE
> memory.

  What OS are you running?  Despite ulimit being "unlimited", your kernel
may have a limit on either the number of open files, or the number of file
handles.

steve

Re: Server Overload

From
brianb-pggeneral@edsamail.com
Date:
Steve Wolfe writes:

> > I've seen brief posts regarding server loads, distrubution for heavy
> loads,
> > etc, but don't recall if there were any solutions...
> >
> > Anyways...We are running a Postgres DB against multiple frontend
> > webservers.  For most of the time, everything runs fine.  Then, all of a
> > sudden, everything will start to go all funky.  Crashing...Errors...Etc...
> >
> > When I log onto the DB server and try to do anything, I get "Too many open
> > files in system."  ulimit is set to unlimited and there is PLENTY of FREE
> > memory.
>
>   What OS are you running?  Despite ulimit being "unlimited", your kernel
> may have a limit on either the number of open files, or the number of file
> handles.

I'd also check on how your web server connects to Postgres. If you're using
a webserver that pools database connections (e.g. Apache with mod_perl and
DBI, AOLserver,IIS) you should be able to handle a large amount of web
traffic while maintaining only a few backend connections. If you're using
CGI, consider that each CGI program establishes its own connection to the
database and allocate resouces accordingly.

Brian
--
Brian Baquiran <brianb@edsamail.com>
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