Re: squid 5.1 gone stable

[Michael Tremer <michael.tremer@ipfire.org>]

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Hello,

> On 15 Aug 2021, at 08:53, Matthias Fischer <matthias.fischer(a)ipfire.org> wrote:
> 
> Hi,
> 
> On 13.08.2021 11:22, Michael Tremer wrote:
>> Hello,
>> 
>>> On 7 Aug 2021, at 17:13, Matthias Fischer <matthias.fischer(a)ipfire.org> wrote:
>>> 
>>> Hi,
>>> 
>>> ...for the records...: ;-)
>>> 
>>> Today I tested building 'squid 5.1' with our usual configure options:
>>> 
>>> ...
>>> --with-dl \
>>> --with-filedescriptors=$(( 16384 * 64 )) \
>>> --with-large-files \
>>> --without-gnutls \
>>> ...
>>> 
>>> No errors in '_build.ipfire.log' for this 'squid' - except:
>>> 
>>> ...
>>> checking for library containing log... none required
>>> configure: forcing default of 1048576 filedescriptors (user-forced)
>>> checking Default FD_SETSIZE value... 1024
>>> checking for getrlimit... yes
>>> checking for setrlimit... yes
>>> checking Maximum number of filedescriptors we can open... 32768
>>> configure: Default number of filedescriptors: 1048576
>>> ...
>>> 
>>> So the maximum number of filedescriptors which are possible for 'squid
>>> 5.1' are 32768!?
>>> 
>>> Ok then. I rebuilt the whole thing with the "maximum":
>>> 
>>> ...
>>> --with-filedescriptors=32768 \
>>> ...
>>> 
>>> But no change. During starting, 'squid 5.1.' still complains:
>>> ...
>>> NOTICE: Could not increase the number of filedescriptors
>>> With 4096 file descriptors available
>>> ...
>>> 
>>> This is the value reported by 'ulimit -n' on my IPFire / Core 158.
>>> 
>>> Currently, only 'squid 4.16' can increase this number under *exactly*
>>> the same environment.
>>> 
>>> What consequences could it have, respectively!?
>> 
>> This is the maximum amount of connections squid can open.
> 
> What makes me wonder: during build, 'squid' says it can open '32768',
> during start its '4096'. If someone knows why, please enlighten me... ;-)

4096 is the default maximum number of files any process can open at the same.

This is to protect the system from going crazy by having too many open files (because I think the file descriptor table used to be of a static size in older versions of the kernel).

>> I suppose this is enough and I can live with 32k. We should remove the field from the UI then.
> 
> Me too, but are 4096 enough?

No. I don’t know why the squid team isn’t handling this better. We are hitting this problem every time we update to a new version.

I suppose this is fine for testing.

You can try adding “ulimit -n 32768” to the squid init script and then it should be able to open up to 32k files.

-Michael

> Besides, I would wait to push '5.1' - I even didn't see an official
> annoncement yet.
> 
> Best,
> Matthias