Re: [squid-users] problem with loaded server

From: Marcus Kool <marcus.kool_at_urlfilterdb.com>
Date: Mon, 09 Apr 2012 10:46:31 -0300

free -m reports unused memory. Most likely a large part is used
by the large dynamic file system cache of the kernel.

Unless you have an extremely important reason to use the unsupported
Squid 2.5 it is better to upgrade to 3.1.

Marcus

On 04/08/2012 04:04 AM, Mustafa Raji wrote:
> thanks marcus for you reply
> according to your calculation 2 GB for the system + 12 GB for the cache directories + 1 GB is for the cache_mem (in my situation now)
> checking the process size with top command it shows that the squid process size is 12 GB (49%), now when i check the status of my server ram by using the free -m command the free amount of ram available is 400 MB, checking in the top and ps command to find another process takes the rest of my ram , not found, where does these amount of ram approximately 12 GB gone, and in situation with memory leak if exist does the size of squid is growing and can by noticed clearly in the top program,
> my squid is 2.5stable9, and the os is fedora
> thanks with my best regards
>
> --- On Sat, 4/7/12, Marcus Kool<marcus.kool_at_urlfilterdb.com> wrote:
>
>> From: Marcus Kool<marcus.kool_at_urlfilterdb.com>
>> Subject: Re: [squid-users] problem with loaded server
>> To: "Mustafa Raji"<mustafa.raji_at_yahoo.com>
>> Cc: squid-users_at_squid-cache.org
>> Date: Saturday, April 7, 2012, 10:33 PM
>>
>>
>> On 04/07/2012 04:37 PM, Mustafa Raji wrote:
>>> hi
>>> i have server which i think it's overloaded
>>> i checked the TIME_WAIT TCP connection status it's
>> normal and below the limits of the os, and file descriptor
>> is set for high value and no warning in cache.log about the
>> file descriptor, so i think it's memory issue or disk
>> bottleneck, the cache contain 6 hard disk for cache, with 12
>> cache_dir aufs directory, with 115 GB for each partition my
>> Ram is 26 GB, calculating that for each 1 cached GB i need
>> 32 MB, so this amount of ram is not enough, of course with
>> 2024 cache_mem, as a solution to the problem i disabled four
>> partition, and reduce cache_mem to 1024, the server works
>> find but with low memory in the peak hours it reaches to 400
>> MB , but no browsing suffering from my client, the problem
>> could be considered a disk bottleneck and when i disabled 4
>> partition the problem goes ? of i can consider it as a
>> memory issue, i realy can't check page fault in the cachemgr
>> because i don't have the right to install it in working
>> server, of course additionally
>>> cache.log file show me so many invalid
>> request, does the number of these invalid request slowing
>> the performance of the box,
>>> when i disabled my cache directory i put # sign after
>> my cache_dir directives, does that mean i cant make these
>> partition back to work, because of fresh object in that
>> partition not exist, and what squid will do if it caches
>> objects in the working cache directory and the same object
>> is exist in the disabled partition, does that effect the
>> performance of squid if partition enabled a gain, i hope i
>> was clear in my explanation,
>>> also i have test squid box, i have two squid installed
>> in the /usr/local/ directory when i start one of them it
>> does not take the squid.conf that exist in it's etc
>> directory so, i must start it with the -f option to force it
>> with the configuration file, what is the cause of these
>> problem please
>>> thank you with my best regards
>>
>> http://wiki.squid-cache.org/SquidFaq/SquidMemory:
>> 64-bit Squid needs 14 MB memory index per 1 GB disk cache
>>
>> Squid has best performance with one cache dir per disk, so
>> you should reduce the number of cache directories from 12 to
>> 6.
>>
>> The system needs RAM for OS, file system buffers, other
>> processes and network buffers.
>> Let's reserve 2 GB for that.
>>
>> Memory cache is much faster than disk cache, but the disk
>> cache is larger.
>> I suggest to set cache_mem to 8 GB and the total disk cache
>> to 690 GB (6*115) which requires 690*14=9.6 GB in-memory
>> index.
>>
>> Squid will than at least claim 17.6 GB memory. This is
>> a good starting point for finetuning.
>> You can probably add more disk cache and/or more memory
>> cache.
>>
>> If you run 2 squid proxies, they should have separate disks
>> for their disk cache and one cache dir per disk.
>> For 2 equally configured Squid proxies you could use this:
>> cache_mem 6 GB and total disk cache 345 GB (3*115) which
>> requires 4.8 GB in-memory index.
>> Each Squid will than at least claim 10.8 GB memory.
>>
>> Marcus
>>
>
>
Received on Mon Apr 09 2012 - 13:46:35 MDT

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