Re: [squid-users] limit squid memory ram use - squid becomes slow when ram full

 On Mon, 11 Apr 2011 07:52:41 -0400 (EDT), rpereyra_at_lavabit.com wrote:
> Hi
>
> How I can limit the ram memory use in my squid/tproxy box ?
>
> I have a fast server with 16Gb ram. The average bandwidth is about
> 60-70
> Mb/s.
>
> The bridge works well but when the cache and memory becomes full its
> goes
> slow and becomes unusable.
>
> The cache is 10G size.
>
> I see that a few hours to be working and have used the 16 GB of RAM
> starts to run slow.
>
> Any help ?. I have configured some memory optimization options but
> looks
> don't help for me.
>
> Thanks in advance
>
> roberto
>
> This is my config:
>
> -------------------------------------
>
> cache_mem 10 MB
> memory_pools off
> cache_swap_low 94
> cache_swap_high 95
>
 <snip>
> # Example rule allowing access from your local networks.
> # Adapt to list your (internal) IP networks from where browsing
> # should be allowed
> acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
> acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
> acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
> acl localnet src fc00::/7 # RFC 4193 local private network range
> acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged)
> machines
>
> acl net-g1 src 200.117.xxx.xxx/24
> acl net-g2 src 200.xxx.xxx.xxx/24
> acl net-g3 src 190.xxx.xxx.xxx/24
>
 <snip>
>
> http_access allow net-g1
> http_access allow net-g2
> http_access allow net-g3

 Being "allow" you can grab some extra speed by combining these all
 under one ACL name. "localnet" being the standard one for local network
 ranges.

 <snip>
>
> # Uncomment and adjust the following to add a disk cache directory.
> cache_dir ufs /var/spool/squid 10000 64 256
>
 <snip>

 Given those cache sizes, your Squid box should be using around 110 MB
 of RAM for index plus a little. Even assuming a worst-case of a minutes
 traffic accumulated in transit buffers comes nowhere close to filling 16
 GB up.

 Some questions that may help narrow down where the slow is coming from:
  What version of Squid is this?
  What are your avg object size?
  How many concurrent client connections?
  "slow" and "normal" response speeds?
  Do you notice any change in the Squid->Internet request types during
 the slowdown? (ie a move to extra MISS/HIT/IMS/REFRESH)

 And like Michael said the disk IO stats are important to look at. When
 the cache_dir gets to 94% full it will start spending CPU and disk
 cycles on erasing objects. If it reaches 95% a larger portion of cycles
 get used until it drops down below 94% again.

 Amos
Received on Mon Apr 11 2011 - 23:26:36 MDT