[squid-users] Why Squid on CentOS is faster than Debian ?

[Amos Jeffries]

On 3/04/19 11:00 am, David Touzeau wrote:
> 
> Le 02/04/2019 à 18:06, Alex Rousskov a écrit :
>> On 4/2/19 1:23 AM, David Touzeau wrote:
>>> Le 01/04/2019 à 23:22, Alex Rousskov a écrit :
>>>> Do your Squids use shared memory for the memory cache? See
>>>> memory_cache_shared (even if you do not set it explicitly).
>>>> http://www.squid-cache.org/Doc/config/memory_cache_shared/
>>> The test did not use workers
>> That does not answer my question. Do you use Rock cache_dir(s)?
>>
>>
>>>> Any significant difference in mgr:info and mgr:counters output after a
>>>> test that only has memory hits?
>> The question still stands. I would recommend testing this with a single
>> URL and a fixed/same number of requests submitted by a reliable proxy
>> benchmarking tool or at least a wget/curl script.
>>
>>
>>> Do you know why CentOS objects are 34 bytes smaller than Debian ?
>> Something in your test setup or environment results responses (or
>> response delivery statistics) that differ in size between the tests. I
>> do not know what it is, and the number of possible options is too large
>> to guess correctly: It could be anything from 32-vs-64 bit OSes, to
>> locale differences, to Squid host name, to Cookies, to test setup
>> imperfections, to Squid statistics collection bugs, etc., etc.
>>
>> Have you compared the responses received by the client (headers and
>> all)? Do they differ by 34 bytes? I suggest testing with a single URL
>> that produces different results and then digging down to identify the
>> difference (starting with comparing responses).
>>
>> Alex.
> 
> Thanks Alex for these ways to investigate.
> 
> We will try to get more precise for the tests
> 
> We have reduced the squid.conf to the minimal way in order to be sure
> that nothing can disturb testing.
> 
> Only one cache, no rock, no workers, no tuning
> 
> Amos says that perhaps the C++ version can make some tweaks in this case
> we will start to do the same tests with Ubuntu that uses the most recent
> kernels and C++
> 
> But for the moment
> 
> - without intelligence
> - Without investigations efforts
> - Just by compiling squid
> 
> To resume
> 
> Centos 7 is 10 times faster than Debian 7
> Centos 7 is 400%  faster than Debian 9
> 
> Debian 9 is a  little faster than Debian 7
> 


Can you provide the same numbers for Deb 7 that you did for Deb 9 ? so
we can see what exactly "a little faster" means.

PS. your first post which said "10 times faster" also said it was for
"Debian 9 net install" - no Debian 7.


> We will keep updated for Unbuntu.
> 

Thanks.


Amos