Re: [squid-users] optimizing squid and FreeBSD

Michel Santos wrote:
>> You can add kern.maxfilesperproc=8192 in /etc/sysctl.conf to increase your
>> squid file descriptors to 8192.
>> You may also have to change your kern.maxfiles parameter to say about 8192
>> or 16384.
>>
>>
>
> all this sugestions are kind of high, hardly you get over 2000 open files
> unless you have a heavy loaded server, this starts somewhere over 6-10mb/s
> sustained http througput when you may need more open files
>

High bandwidth, high latency connections (satellite links) also eat file
descriptors quite quickly.

> when you use coss you do not get even close to half of it
>
> on FBSD you ever should query your system as with sysctl kern.openfiles to
> see what is going on and then when *really* coming to the limit you might
> like to raise it a little and otherwise not
>

Good advice for any setup.

>> Well if your proxy serves less than 30 requests per second, then ufs
>> storage is fine. However if your demands are above 30 requests per second,
>> then either diskd and aufs will be good. However you may need to tweak
>> your kernel to implement diskd for FreeBSD.
>>
>
> you say it so easy as if were that easy, firstable what your machine
> supports and needs is relative to the machine's processing power. There is
> no such 30 req/sec limit or switch-over-rule ...
>

For what it's worth, the 30 requests/second suggestion is straight from
the most active developer on the Squid-users mailing list:
http://www.squid-cache.org/mail-archive/squid-users/200701/0433.html
(see close to the bottom of that message).

> but I agree, on FreeBSd you might consider diskd but the difference is
> small and depends on the machine and the throughgoing http-traffic and if
> your HD can really take the load (or better: answer the requests in time)
>

 From what I understand, FreeBSD 5 and up does quite well with aufs.
Obviously a number of people are experiencing great success using COSS.

> so my opinion hear is using ufs is good and stable and fits high load for
> whom is not a specialist in system fine tuning, if you are knowing nasty
> kernel stuff *and* have really nasty hardware and like to get the most out
> of it then you should go diskd - but - better having a perfect UPS and a
> server which never crashs, you may loss your cache content, anyway it's a
> long way to get this 5-10% more (in comparism to ufs)
>
> aufs? hands off
>

See the above linked message. There is almost no reason to use ufs.

> if you want to tune diskd read first a lot of postgres sql tuning matter
> which are the only lonly guys which seem ever having worked serious
> (except me of course ;) ) with this IPC stuff on FreeBSD. What you find on
> squid's website regarding FreeBSD makes diskd work on old versions but not
> tuned.
>

Suggested settings are always welcome, but the most general advice is
available from http://wiki.squid-cache.org/BestOsForSquid. Note there
are not much in the way of OS tuning tips. Unless you are really
pushing the boundaries of what Squid is capable of, they just won't buy
you much.

>
> michel
>
> ...
>
>

Chris
Received on Mon Mar 19 2007 - 23:53:42 MDT