[squid-users] Async I/O with RH 9 (NPTL) problem ?

Hi everyone !

I'm testing squid-2.5STABLE4 on a compaq ProLiant DL380 G3 (2 Xeon 2.4
with hiperthread) and 2 Gb memory running Red Hat 9 .
My compile options was :

configure options: --host=i386-redhat-linux --with-aufs-threads=32
--build=i386-redhat-linux --target=i386-redhat-linux-gnu
--enable-removal-policies=heap,lru --with-pthreads
--enable-storeio=aufs,coss,diskd,ufs --enable-snmp
--disable-hostname-checks --enable-underscores --disable-ident-lookups
--prefix=/opt/squid-2.5.STABLE4

I'm using squid as a transparent proxy (http accelerator) and I set my
cache_dir as aufs (with 32 threads set on compile) on ext2 partition
that is mounting a 36Gb ultra-scsi disk. Nothing access this disk except
squid.
Now the problem is :

"squidaio_queue_request: WARNING - Queue congestion"

I'm getting this messages a lot on cache.log and after some time squid
eventually freezes after showing the following messages :

2003/09/25 17:56:26| squidaio_queue_request: WARNING - Queue congestion
2003/09/25 11:57:43| ctx: enter level 0:
'http://humortadela1.uol.com.br/h/piad/im/pia
f'
2003/09/25 11:57:43| squidaio_queue_request: WARNING - Disk I/O
overloading
2003/09/25 11:57:43| squidaio_queue_request: Queue Length: current=787,
high=787, low=3
2003/09/25 11:57:59| ctx: exit level 0
2003/09/25 11:57:59| ctx: enter level 0:
'http://humortadela1.uol.com.br/h/piad/im/piaf'
2003/09/25 11:57:59|squidaio_queue_request: Async request queue growing
uncontrollably!
2003/09/25 11:57:59|squidaio_queue_request: Syncing pending I/O
operations.. (blocking)

I benchmark the disk with IOzone and got 50Mb/s of throughput!
I didn't have this problem at all (not even the warnings) when using Red
Hat 7.3.

So I'm wondering if squid Async I/O have problems using NPTL (native
posix thread library) implemented within RH9....
I'm now trying to disable NPTL on RH9. I found out that exporting
LD_ASSUME_KERNEL=2.2.5 should disable it , but I didn't overcome the
problem doing it on squid compilation and putting on RunAccel script.
I'm almost downgrading my linux installation to RH 7.3 now ...
Does anyone have successfully run squid-2.5STABLE4 on RH9 that handles
good traffic on it (like 80 Mbs) ?

Thanx everyone.
Bruno Marcondes
UOL Sysadmin.
www.uol.com.br
Received on Mon Sep 29 2003 - 19:16:42 MDT