there are hints in the SUPPORT doc on how to debug such problems. there
was also several "Hanging process" threads in the past weeks with more
tips, search in the archives for keywords gdb, .gdbinit, curinfo
if you can get more insight from those tips, we can help more.
On Sun, 9 Jan 2000, James Furness wrote:
> I'm looking for some help getting apache to run reliably. Apache 1.3.9 with
> mod_perl 1.21 and Perl 5.005_03 is running on a dual P500 with 1 Gb of RAM
> running Redhat 6.1. We run about 5 sites off the box, most of which are
> fairly high traffic, and use a lot of CGI and
> MySQL 3.22.25 is used with Apache::DBI.
>
> The major problem seems to be a memory leak of some sort, identical to that
> described in the "memory leak in mod_perl" thread on this list from October
> 1997 and the "httpd, mod_perl and memory consumption (long)" thread from
> July 1997.
>
> The server runs normally for several hours, then suddenly a httpd process
> starts growing exponentially, the swapfile usage grows massively and the
> server starts to become sluggish (I assume due to disk thrashing caused by
> the heavy swap usage). Usually when this started to happen I would log in
> and use apachectl stop to shutdown the server, then type 'killall httpd'
> several times till the processes finally died off, and then use apachectl
> start to restart apache. If I was not around or did not catch this, the
> server would eventually become unresponsive and lock up, requiring a manual
> reboot by the datacentre staff. Messages such as "Out of memory" and
> "Callback called exit" would appear in the error log as the server spiralled
> down and MySQL would start to have trouble running.
>
> To combat this, I created a script to monitor load and swapfile usage, and
> restart apache as described above if load was above 7 and swapfile usage
> above 150Mb. This script has kept the server online and we now have an
> uptime of something like 22 days (previously no more than 1 day), but the
> script is getting triggered several times a day and no more "Out of memory"
> messages are appearing, but the situation is not ideal.
>
> I have tried adding:
>
> sub UNIVERSAL::AUTOLOAD {
> my $class = shift;
> Carp::cluck "$class can't \$UNIVERSAL::AUTOLOAD!\n";
> }
>
>
> As recommended by the developers guide, which flooded the error log with the
> text below being printed roughly once a second in the error log:
>
> ---------
> Apache=SCALAR(0x830937c) can't $UNIVERSAL::AUTOLOAD!
> Apache=SCALAR(0x8309364) can't $UNIVERSAL::AUTOLOAD!
> DBI::DBI_tie=HASH(0x82dd16c) can't $UNIVERSAL::AUTOLOAD!
> IO::Handle=IO(0x820aabc) can't $UNIVERSAL::AUTOLOAD!
> DBI::DBI_tie=HASH(0x82dd16c) can't $UNIVERSAL::AUTOLOAD!
> IO::Handle=IO(0x820aabc) can't $UNIVERSAL::AUTOLOAD!
> DBI::DBI_tie=HASH(0x82dd16c) can't $UNIVERSAL::AUTOLOAD!
> IO::Handle=IO(0x820aabc) can't $UNIVERSAL::AUTOLOAD!
> DBI::DBI_tie=HASH(0x82dd16c) can't $UNIVERSAL::AUTOLOAD!
> IO::Handle=IO(0x820aabc) can't $UNIVERSAL::AUTOLOAD!
> ----------
>
> I've pretty much exhausted any ways I can think of to trace this problem,
> such as i've tried to eliminate memory leaks in code by removing some
> scripts from mod_perl and running them under mod_cgi and i've tried tweaking
> MaxRequestsPerChild both without any success.
>
> One thing that was mentioned in a previous thread was that using 'exit'
> could confuse perl, and exit() is used fairly heavily in the scripts since
> most are converted to mod_perl from standard CGIs, but i'd prefer not to
> have to remove these since the structure of the scripts is reliant on some
> form of exit statement. Is there some alternative to exit()?
>
> I've also had a look at some of the patches to Apache.pm and Apache.xs
> suggested in the previous threads, and these seem to have been incorporated
> into mod_perl 1.21.
>
> Are there any other solutions I could try to this problem? Does anyone know
> what might be causing this?
>
> The second problem I have is when loading pages, usually CGI, but I think
> this has happened on some static pages, what IE5 describes as "Server not
> found or DNS error" is experienced. Originally I thought this was the server
> hitting MaxClients (150) since it usually occurs at the same time as massive
> surges of hits, and /server-status usually shows 150 httpd processes have
> been spawned, however I increased MaxClients to 200 recently and the error
> has continued to happen, even though /server-status doesn't show any more
> than about 170 processes spawned. I have not ruled out DNS server troubles
> or backbone problems (We've had a few routing troubles recently that slowed
> things down, but not actually cut off traffic or anything like that), but I
> am at a loss as to what else could be causing this so I thought i'd ask
> whilst i'm on the subject of server problems :)
>
> Thanks in advance,
> --
> James Furness <[EMAIL PROTECTED]>
> ICQ #: 4663650
>
