Re: [squid-users] Could this be a potential problem? Squid stops working and requires restart to work

> Amos Jeffries wrote:
>> On Mon, 07 Dec 2009 14:47:22 -0900, Chris Robertson <crobertson_at_gci.net>
>> wrote:
>>
>>> Asim Ahmed @ Folio3 wrote:
>>>
>>>> Hi,
>>>>
>>>> I found this in cache.log when i restarted squid after a halt!
>>>>
>>>> CPU Usage: 79.074 seconds = 48.851 user + 30.223 sys
>>>> Maximum Resident Size: 0 KB
>>>> Page faults with physical i/o: 0
>>>> Memory usage for squid via mallinfo():
>>>> total space in arena: 7452 KB
>>>> Ordinary blocks: 7363 KB 285 blks
>>>> Small blocks: 0 KB 1 blks
>>>> Holding blocks: 14752 KB 94 blks
>>>> Free Small blocks: 0 KB
>>>> Free Ordinary blocks: 88 KB
>>>> Total in use: 22115 KB 297%
>>>> Total free: 88 KB 1%
>>>>
>>> This is not likely the source of your trouble...
>>>
>>> http://www.squid-cache.org/mail-archive/squid-users/200904/0535.html
>>>
>>> Chris
>>>
>>
>> That would be right if they were negatives or enough to wrap 32-bit back
>> to positive.
>>
>> Since its only ~300% I'm more inclined to think it's a weird issue with
>> the squid memory cache objects.
>>
>> The bug of this week seems to be a few people now seeing multiple-100%
>> memory usage in Squid on FreeBSD 7+ 64-bit OS. Due to Squid memory-cache
>> objects being very slightly larger than the malloc page size. Causing 2x
>> pages per node instead of just one. And our use of fork() allocating N time
>> the virtual-memory which mallinfo might report.
>>
>> Asim Ahmed: does that match your OS?
>>
>>
>> Amos
>>
Asim Ahmed @ Folio3 wrote:
> I am using Red Hat Enterprise Linux Server release 5.3 (Tikanga) with
> shorewall 4.4.4-2 and Squid 3.0 STABLE20-1. My problem is kind of wierd.
> Squid stops working after like a day and i need to restart it to let
> user browse or use internet. Any parameters to look for? Out of 2 GB RAM
> only 200 MB RAM is left free when i find squid halted (before
restrting it).

Look out for the cache_mem, and 10% of the cache_dir size worth of RAM
is also gobbled by Squid for indexing the cache_dir contents. Then a
pile of other RAM for other transactions.

If you can please grab as much info about the memory situation on the
box as possible when Squid hangs up like this. It might be helpful in
tracking down whatever is happening.

An strace of Squid child worker process to find out exactly what Squid
is processing can be very useful.

>
> One more question i have is: In just two days my squid cache has grown
> to 500 MB. I've set cache_dir as 10GB ... I believe it will not take
> long before it will reach this limit! what happens then? does it start
> discarding old cache objects or what?
>

Yes, it starts discarding objects that are too old or unused for long
periods. To make as much space as needed for the new incoming ones. You
will see it reach a peak and level off just under the 10GB mark,
(leaving space in case you get a sudden burst of large cacheable items).

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE7 or 3.0.STABLE20
   Current Beta Squid 3.1.0.15