[squid-users] squid workers question

[Alex Rousskov]

On 03/20/2017 09:20 AM, Matus UHLAR - fantomas wrote:
> On 10.03.17 08:52, Alex Rousskov wrote:
>> Sorry, but that 2010 documentation is outdated. It was written before
>> Rock store, a 2011 feature that changed what "SMP mode" means. This is
>> my fault. Here is a replacement draft that I was working on until wiki
>> went down:
>>
>>> NAME: workers
>>> DEFAULT: 1
>>>     Number of main Squid processes or "workers" to fork and maintain.
>>>
>>>     In a typical setup, each worker listens on all http_port(s) and
>>>     proxies requests without talking to other workers. Depending on
>>>     configuration, other Squid processes (e.g., rock store "diskers")
>>>     may also participate in request processing. All such Squid processes
>>>     are collectively called "kids".
>>>
>>>     Setting workers to 0 disables kids creation and is similar to
>>>     running "squid -N ...". A positive value starts that many workers.

> The default of 1 (only) creates kids for each rock store configured.

What makes you think that? I believe "workers 1" in the presence of rock
cache_dirs should create one kid to handle HTTP transaction _plus_ one
kid for each rock cache_dir.


>>>     When multiple concurrent kids are in use, Squid is said to work in
>>>     "SMP mode". Some Squid features (e.g., ufs-based cache_dirs) are not
>>>     SMP-aware and should not or cannot be used in SMP mode.
>>>
>>>     See http://wiki.squid-cache.org/Features/SmpScale for details.

> very nice, thanks. However this is not meant for the wiki, but for:
> http://www.squid-cache.org/Doc/config/workers/

To be more precise, the text is meant for src/cf.data.pre, from which
squid.conf.documented (and Doc/Config pages) are generated from. Not
sure why you say "However" though.


> maybe that pages could be updated (all but 3.2 versions are the same).

Once the above worker documentation changes are polished and committed
to the Squid repository, the affected generated pages/files will be
updated automatically.

The documentation for earlier versions may never be updated though -- it
depends on whether the changes are going to be ported and committed to
the code branches corresponding to those earlier versions.


>> The final version will probably move and extend the terminology-related
>> text to the SMP section preamble -- it is kind of wrong to talk about
>> diskers when documenting workers. Improvements and constructive
>> suggestions welcomed!
> 
> compared to current version I'd change it to:
> 
>     1: start one main Squid process daemon (default)
>            "no SMP" when rock store is not used
>            "SMP" when rock store in use

I agree that we should add something like this as a common-case example
of general rules. Thank you.

Alex.