Angela Burrell wrote:
Squid users,
I am running Ubuntu Edgy 6.10 for AMD64 which is Kernel 2.6.17. I have squid
2.6.STABLE9 that I installed from source.
This is not a production server yet, so it was just kind of sitting there
for the past few days, today when I turned on the screen I saw messages
similar to the following:
(numbers) Out of memory: Kill process XXX (apache2) score XX and children.
(numbers) Out of Memory: Killed process XXX (apache2).
(...)
(numbers) Out of memory: Kill process XXX (squid) score XX and children.
(numbers) Out of Memory: Killed process XXX (squid).
I don't know too many linux commands, but I looked on google and found the
free command. My computer has 1 GB of RAM and I only had 10 MB free, but I
had about 75% of my swap space left. (I have about 3 GB of swap).
Free memory in Linux (and BSD, and Solaris, etc.) is a funny thing if
you are used to the Windows world. The Gentoo Wiki has a nice
explanation on this
(http://gentoo-wiki.com/index.php?title=FAQ_Linux_Memory_Managementoldid=97182).
Stop after the first paragraph as the rest is a bit irrelevant. The
short answer is use free -m and look at the +/- buffers/cache line.
But by the time processes start to get killed, there is a real problem.
I did /etc/init.d/squid stop which replied [ok] but then when i look in
top I see that I still only have 10 MB free memory, and most of the pid's
on the list belong to squid. Why are 30,000 squid processes running after I
type squid stop.
That depends entirely on what the initialization script does. If it
just runs /path/to/squid -k shutdown and checks the result of that call,
any open connections will be given a certain amount of time (default is
30 seconds last time I checked). But 30,000 processes sounds like a lot
(to put it mildly). Why are there 30,000 processes related to squid
would be the question I would want answered.
According to ps aux, /usr/sbin/squid -D -sYC has 9486 entries (AFTER I typed
squid stop.)
Yikes. If I'm not mistaken (which happens a lot more frequently than I
would like) that means that squid was started over 9,000 times without
any of them dying. I'm not even sure how that would be possible. Any
time I try to start more than one instance of Squid the second one dies
complaining that the port it wants to use can't be opened
Assuming that it would be possible to start squid 9000 times that would
explain the number of processes. Each parent Squid process usually
kicks off the child process (that handles the requests) and an unlinkd
process (which gets rid of expired cache objects). Optionally
authentication processes and external_acl processes are also started.
On our production server we have 512 MB of RAM and squid 2.4.STABLE7 and
this has never happened.
What can I do?
Note that during the last 5 days this computer was unplugged from the
network so, it's cache cannot be full!
Monitor the cache.log. Make sure the pid file is successfully written.
Check for any other funny business. Figure out how multiple thousand
squid processes were started without interfering with each other and dying.
Chris
