[squid-users] squid workers question

[Amos Jeffries]

On 10/03/2017 5:14 a.m., Matus UHLAR - fantomas wrote:
>> On 10/03/2017 3:21 a.m., Matus UHLAR - fantomas wrote:
>>> I have installed squid 3.4.8 on linux 3.16/64bit (debian 8 / jessie
>>> version)
> 
>>> - does this version have known memory leaks?
>>> http://www.squid-cache.org/Versions/v3/3.5/ChangeLog.txt
>>> shows some leaks fixed but they all seem to be related to something we
>>> don't
>>> use (certificated, Surrogate capability), unless the:
>>>
>>> "Fix memory leak of HttpRequest objects" that is fixed in 3.5.16 applies
>>> to 3.4 too.
> 
> On 10.03.17 05:00, Amos Jeffries wrote:
>> IIRC that does, and there were some issues with CONNECT exceeding
>> configured limits.
>>
>> The Bug 3553 issue
>> <http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-13903.patch>
>>
>> can also cause nasty issues on busy proxy as the cache disk overflows
>> from too-slow purging.
> 
> seems that my memory problem is somehow related to 4g of "2K Buffers"
> whatever that means. This is cachrmgr output:
> 
> 
>         (bytes)    KB/ch    obj/ch    (#)    used    free    part   
> %Frag    (#)    (KB)    high (KB)    high (hrs)    %Tot    (#)   
> (KB)    high (KB)    high (hrs)    %alloc    (#)    (KB)    high (KB)   
> (#)        %cnt    %vol    (#)/sec
> 2K Buffer    2048                                1986398    3972796   
> 3972796        0.00        89.763    1986390    3972780   
> 3972796        0.00        100.000    8    16    198        10736355   
> 4.914    19.208    0.009
> 

Ah. So anything that is using a generic 2KB of memory. Tricky to track
down :-(.

I would look at the next few entries to see if there is a good clue
about what system might be worth a closer look (largest amount of things
active, or anything else not being released). Mostly it is I/O using the
various Buffer's, but some other things do as well.


> 
>>> cache_dir rock /var/spool/squid3/rock 1024 max-size=32768
>>> #cache_dir aufs /var/spool/squid3 8192 16 256 min-size=32769
>>>
>>> are those correct values? (bug 3411 says something about 256B metadata)
> 
>> Those 256 Byte will matter for Squid-3.4.
> 
> doesn't it for later squid versions?

Nope :-). Squid-3.5 'large rock' feature adds slots as needed to fit the
extra meta bytes. So 32KB is no longer an absolute limit.

Amos