[squid-users] Question about shared memory in Squid 3.5

[Amos Jeffries]

On 8/03/2016 5:48 a.m., Alex Rousskov wrote:
> On 03/07/2016 04:49 AM, Silamael wrote:
> 
>> We're updating to Squid 3.5 under OpenBSD and have some issues with the
>> apparently new shared memory behavior:
> 
>> 1. Squid always creates three shared memory files and does not remove
>> these on shutdown
> 
>> 2. As we're running multiple complete different configuration on the
>> same machine on different ports, the shared memory files collide and
>> Squid does not start up properly
> 
> If Squid creates shared memory segments without you using SMP features,
> it is a Squid bug. I recall fixing one such bug in Squid v4/trunk
> recently. Perhaps it exists in v3.5 as well. I recommend filing a bug
> report while specifying exactly which files are being created.
> 
> If Squid does not remove shared memory segments on shutdown, it is a
> Squid bug. I recall fixing one such bug in Squid v4/trunk recently.
> Perhaps it exists in v3.5 as well. I recommend filing a bug report while
> specifying exactly which files are left behind.
> 

But note that this recommendation only applies if the files are left
after a single Squid is run then shutdown.

Having a second Squid fail to startup while the first is still running
is expected behaviour if they are running with identical service names.

> 
> FWIW, Squid v4 supports the "-n" command line option to assist with
> running multiple instances on the same box (with or without using SMP
> features). I do not remember whether v3.5 supports that as well but it

3.5 does.

> may. I do not remember whether "-n" support extends to shared memory
> segment names but it should.

It does. That was fixed in 3.5.7.

Amos