Re: [squid-users] Issues with squid-2.6.18 on FreeBSD/COSS/ZFS

As I've said before, COSS needs some fixes to rebuild from a method other than
reading the whole disk in at once.

If someone wants to do it let me know. If someone would like to help sponsor me the
month-odd it'd take then please let me know.

If a customer of mine decides they want it, I'll do it earlier. :)

Adrian

On Thu, Mar 27, 2008, Simonas Kareiva wrote:
> Dear all,
>
> I'm running several instances of squid at my university CAN and have
> recently discovered some annoying things about the cache, so I kindly
> ask for a little help on this.
>
> Every time the squid process is cleanly stopped and started again, it
> finds the cache dirty and starts to rebuild the COSS storage, which
> adds heavy load to the hard drive:
>
> squid2# squid -k shutdown
> squid2# tail -f /var/log/squid/cache.log
> ...
> 2008/03/27 11:16:40| COSS: /squid/coss: syncing
> 2008/03/27 11:16:40| Squid Cache (Version 2.6.STABLE16): Exiting normally.
>
> squid2# squid -Nd1
> ...
> 2008/03/27 11:17:38| Rebuilding storage in /squid/cache (DIRTY)
> 2008/03/27 11:17:38| Rebuilding COSS storage in /squid/coss (DIRTY)
> ...
> 2008/03/27 11:17:38| Done reading /squid/cache swaplog (255 entries)
> 2008/03/27 11:17:39| COSS: /squid/coss: Rebuilding (0 % completed -
> 1/8000 stripes)
>
> after some time:
>
> 2008/03/27 11:18:06| storeSwapMetaUnpack: insane length (67305986)!
> 2008/03/27 11:18:07| storeSwapMetaUnpack: bad type (-1)!
>
> after some more time:
> 2008/03/27 11:19:48| COSS: /squid/coss: Rebuild Completed
>
> For about two minutes (in the given example - between 11:17 and 11:19)
> the cache responds poorly to client requests due to heavy (near 100%)
> /dev/da2 load (from gstat). During that time, of course, several
> TCP_SWAPFAIL_MISS errors appear on the access.log. After the cache is
> rebuilt, the COSS engine significantly reduces the load on the system,
> when compared with simple ufs storage, so my preference would be to
> use COSS together with ufs. Under current deployment the cache
> receives an average of 160 requests/second with peaks of 500req/s.
> When additional coss files are introduced to the squid config, the
> period of cache rebuilding during startup is greatly extended.
>
> The question is - have I misconfigured anything? If yes, then what
> should I change to avoid the cache to be rebuilt at every startup? Any
> help or comments will be appreciated.
>
> squid 2.6.18 runs on FreeBSD 7.0-STABLE with the following additional
> options in the kernel:
>
> options SHMSEG=16
> options SHMMNI=32
> options SHMMAX=2097152
> options SHMALL=4096
> options MAXFILES=8192
> options VFS_AIO
>
> Cache configuration:
>
> squid2# grep ^cache squid.conf
> cache_mem 512 MB
> cache_replacement_policy lru
> cache_dir ufs /squid/cache 8000 16 256
> cache_dir coss /squid/coss 8000 block-size=512 max-size=131072
> cache_swap_log /squid/%s
> cache_access_log /var/log/squid/access.log
> cache_log /var/log/squid/cache.log
> cache_store_log none
> cache_effective_user squid
>
> squid2# zfs list
> NAME USED AVAIL REFER MOUNTPOINT
> squid 8,01G 23,2G 8,01G /squid
> squid2# ls -l /squid/
> total 8393870
> drwxr-xr-x 18 squid squid 18 Kov 27 10:12 cache
> -rw-r--r-- 1 squid squid 8589934592 Kov 27 11:04 coss
> -rw-r----- 1 squid squid 12688 Kov 27 11:08 squid.cache
> -rw-r----- 1 squid squid 4064372 Kov 27 11:08 squid.coss
>
> squid2# grep ^da2 /var/run/dmesg.boot
> da2 at ahc0 bus 0 target 4 lun 0
> da2: <SEAGATE ST336607LW DS04> Fixed Direct Access SCSI-3 device
> da2: 40.000MB/s transfers (20.000MHz, offset 8, 16bit)
> da2: Command Queueing Enabled
> da2: 34732MB (71132959 512 byte sectors: 255H 63S/T 4427C)
>
>
> --
> Simonas Kareiva

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