Re: [squid-users] Performance tuning Squid box for ISP traffic

Milind Nanal wrote:
>
> My squid cache (with WCCP2) is running on FreeBSD 5.2 operating system for
> an ISP. This is running fine but I want to tune it for better performance.
> I have used HP DL 140 hardware with 80 GB IDE hard disk & 512 MB RAM.

Hello Milind,
I am also trying to get the best performance of a Squid with WCCP2 for
an ISP, welcome aboard :-)

> 1) How do I check the HIT rate of my Squid BOX. Any utility. I have tried
> couple of access log analyzer but those are taking long time processing &
> scanning the log files ?

Use SNMP (configure --enable-snmp) and MRTG. It also gives you long term
median values.

I haven't tested calamaris, but it seems unsuitable for me, because my
access logs (with log_mime_hdrs on) grow to 3 GB during 5 hours, so I
have to rotate them several times a day. Even if I could store all day
logs, Calamaris would take some CPU to proceed, which could affect the
running Squid (since my Squid box is quite overloaded - load over 3
during peek times).

> 2) Any fine tune parameters for better performance rather than using default
> values in squid.conf ?
- diskd instead of ufs
- cache_mem 200 MB if you have enough of RAM
- maximum_object_size 200 MB (my config, because I want to save traffic)
- ipcache_size 100000 (so DNS does not slow you down)
- httpd_accel_with_proxy off (you are intercepting, right?)

- storage size max 85% of available disk space
   and reply_body_max_size 900000000 allow all (or so, to be a bit
protected agains no content-lenght attack)

> 3)would like to explore more on different cache replacement policies LUR,
> GDSF, LFUDA which one is suitable of an ISP class SQUID box ?
I am running LFUDA at the moment, because I need to save some traffic.
When I have enough stats, I am going to use GDSF and maybe LUR to
compare the results. According the info I have found, LFUDA should be
the best for traffic saving.

And one more remark. People in this list keep saing the reiserfs is the
best. I decided to use ext3, anyway.
According to the performance benchmark in the Duane Wessels book "Squid
the definitive guide", ufs with reiserfs(notail, noatime) has only 61%
Throughput of ufs with ext3fs(event without notaime option).
Does anyone have a comment to this?

The ext3fs is also handy because you can mount it as ext2fs when you
need better disk performance and you believe that your box is stable
enough :-)

Post your parameters here to the list, when your tunning is done, please.

Best regards,
Marji
Received on Wed Dec 08 2004 - 23:14:19 MST