[squid-users] Is Squid can shutdown unused idle redirector's children?

[Yuri Voinov]

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13.02.15 0:49, Amos Jeffries пишет:
> On 13/02/2015 7:01 a.m., Yuri Voinov wrote:
>> Hi gents,
> 
>> subj.
> 
>> And, of course - question. How to do that? I've don't seen this,
>> if it exists.
> 
>> For example, for this config stub:
> 
>> url_rewrite_program /usr/local/bin/squidGuard -c 
>> /usr/local/squidGuard/squidGuard.conf url_rewrite_children 100 
>> startup=0 idle=1 concurrency=0
> 
>> After daily activity, at midnight, still remain near 60
>> processes. Absolutely idle.
> 
>> So, why?
> 
> The idle=1 parameter "Sets a minimum ..."
> 
> It actually is quite expensive to start them. At least one client
> is being held in a pause waiting for it, and others are slowed down
> while the CPU spawns the process.

I understand. But Apache-like model will be better. And so, it works
much years in web-front's. Timeout for idle - then shutdown all idle
processed.

> 
> Chances are high that the next day, or even a few seconds later
> you will need to use them again anyway. So its a bit better to have
> them idle than to discard completely.
> 
> *Particularly* since you have no concurrency for the helper. A
> single
SquidGuard was never been threaded.

> client loading a page with many objects can initiate many parallel 
> requests. Each of which will need to be processed by one of those
> helpers.

I understand. But will be better to have more weak instrumentation to
manage children. Either Apache-like, or default.

First query latency is important, but when I tun out of memory, this
query will never be executed in any case.

Moreover - some kernels - especially after swap out idle process, can
not return it quickly to CPU.

The system, which has permanently low memory, have hi risk to slow
down to deep swaping.

Amos, current mechanism is so ungainly. I want to have more powerful
control over rewriter processes.

Now they live their lives. By the end of the day I have a lot of
running processes that do not do anything. And can occupy more than 1
GB of RAM valuable. And there is no mechanism other than sporadic
displacement of the operating system. If you accidentally took the memory.

It's better than it was before, when I had 100 running redirectors
always and 1.5 GB of memory consumed with the threat of a swap, but
worse than the management of processes in Apache. And, therefore,
memory management.

> 
> Amos _______________________________________________ squid-users
> mailing list squid-users at lists.squid-cache.org 
> http://lists.squid-cache.org/listinfo/squid-users
> 
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