[squid-users] 10 seconds delay squdclient delay

[Javier Barroso]

Hello,

On Fri, Dec 16, 2016 at 5:06 PM, Alex Rousskov
<rousskov at measurement-factory.com> wrote:
> On 12/16/2016 06:20 AM, Amos Jeffries wrote:
>> On 10/12/2016 12:55 a.m., Javier Barroso wrote:
>>> We are having trouble with cachemgr performance. Do you know why
>>> squidclient could delay 10 seconds on mgr:xxx queries ?
>>>
>>> I have looked about any timeout, or network error, or something, but I
>>> did not find nothing
>>
>> The idea that comes to mind (for me) is that it may be a queue delay in
>> the UDS kernel I/O subsystem if your Squid is processing much traffic
>> shared between workers. The SMP coordinator process that arbitrates all
>> that plus generates these reports may be heavily loaded with work.
>
> To test that theory, you can use mgr:xxx queries that target:
>
> * Coordinator itself (without forwarding to any other kids)
> * an idle kid (which can be created for the test if needed)
> * N idle kids (which can be created for the test if needed)
> * a busy kid
> * etc.

I had a case where squid (with the same configuration) hangs 20
seconds, and it have configured 4 workers, so may be this is what is
happening.
Unfortunaly I couldn't get the trace before that such instance was restarted.

Thank you very much