Memory blowout

This has only happened once, but I thought it might be worth mentioning.

Last night my squid process grew out of control until the lack of swap
space killed it off. I have no idea why it would do this. The only
symptom I could see in the logs were these reports:

97/08/25 00:10:00| WARNING: Exceeded 'cache_mem' size (265184K > 143360K)
97/08/25 00:10:00| Perhaps you should increase cache_mem?
97/08/25 00:10:00| storeGetMemSpace stats:
97/08/25 00:10:00| 12 objects locked in memory
97/08/25 00:10:00| 0 LRU candidates
97/08/25 00:10:00| 0 were purged
97/08/25 00:10:00| 0 were released

The amount exceeded just gets bigger and bigger.

97/08/25 03:20:19| WARNING: Exceeded 'cache_mem' size (561776K > 143360K)
97/08/25 03:20:19| Perhaps you should increase cache_mem?
97/08/25 03:20:19| storeGetMemSpace stats:
97/08/25 03:20:19| 0 objects locked in memory
97/08/25 03:20:19| 0 LRU candidates
97/08/25 03:20:19| 0 were purged
97/08/25 03:20:19| 0 were released

eventually it also started saying things like
97/08/25 03:22:05| Restarting ftpget server...
97/08/25 03:22:40| Restarting ftpget server...

The lack of swap finally killed the squid process itself. When
Runcache restarted it, it seemed ok, but took serveral
hours to load the log file, which is somewhat excessive to say the
least. However the OS by this stage was probably a bit upset :(

Most unpleasantly, it happened on 2 hosts at the same time, although one
seemed to start a bit later than the other on its downhill run. The 2
proxies are in a sibling relationship and are parents for a number of
other proxies. I doubt that the stereo effect was co-incidental.

(Squid 1.1.14 on Digital Unix 4.0.)
These boxes have 512M memory each and normally the squid process size is
around 300M mark. Cache_mem is set at 140M which is normally more
than enough.
---------------------------------------------------------------------
Julianne Weekers (J.Weekers@cc.uq.edu.au)
                            Prentice Centre, University of Queensland
                            ph(07-33654404) fax(07-33654477)
Received on Mon Aug 25 1997 - 00:56:10 MDT