Re: [squid-users] running out of file descriptors

ons 2003-04-02 klockan 23.05 skrev Mike Rambo:

> > a) Is it swapping?
>
> Yes, a little anyway. Since we rebooted yesterday is is about 5MB into
> swap. Prior to the reboot it had reached almost 100MB swap after
> approximately 30 days or so uptime. The machine has either 1GB or 1.5GB
> ram installed but I noticed messages in the log that only 896MB would be
> used without a highmem kernel so more wouldn't do me any good anyway
> with the current kernel.

The amount into swap is not as important as the current swapping
activity.

If you use Linux see the output of

vmstat 5

If you see more than occasional activity in the "si" and "so" columns
then your system is swapping.

Other OS:es can be inspected similarly, but the columns may differ
slightly. See the documentation for vmstat, iostat or sar, depending on
platform and taste.
 
> cache_dir diskd /mnt/cache 11000 16 256

One single drive?

> I've also increased cache_mem to 128MB

Should not be needed.

> turned on buffered logs

Only makes a minimal difference. Even with this off your OS buffers the
writes.

> and turned off the store.log to try to minimize unnecessary disk access.

good. store.log is mostly a waste of resources.

> We have 15 redirectors running to squidGuard although after looking at the
> redirector stats I may reduce those to 10.

It is always good to have a few spare. In worst case this may use a
little extra swap space but not much more.

> client_http.requests = 69.485624/sec
> client_http.hits = 30.510768/sec

Fairly medium traffic then.

> File descriptor usage for squid:
> Maximum number of file descriptors: 1024
> Largest file desc currently in use: 930
> Number of file desc currently in use: 637
> Files queued for open: 0
> Available number of file descriptors: 387
> Reserved number of file descriptors: 100
> Store Disk files open: 0
>
> Seems like I am running out of descriptors just as the log says.

Maybe. Increasing the number of filedescriptors will probably help.

> What other things can I look at to see why?

You can look into cachemgr filedescriptor utilization to figure out what
all the filedescriprots are being used for.

It is also interesting to look into the service times. If your service
times for processing cache hits is high then there most likely is other
problems.

You can also try the following settings to reduce the amount of
filedescriptors used:

  half_closed_clients off

And if that does not help

  server_persistent_connections off

and finally if still a problem

  client_persistent_connections off

Regards
Henrik

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