>>> Why does squid eat 100% of processor if the problem is in FS?
> How is your cache_dir defined? aufs (in general) is a better choice
> than ufs, diskd might still have some stability issues under load, and
> coss is a good supplement as a small object cache. Conceivably if Squid
> is set up with a ufs cache_dir mounted as NFS, it's spending a lot of
> time in a wait state, blocked while the I/O completes.
For 6 days uptime:
# vmstat
procs -----------memory---------- ---swap-- -----io---- --system--
-----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
2 0 92 104052 235704 2309956 0 0 3 43 24 33 10 16 73 1 0
As you can see system has spent only 1% of CPU time in I/O wait.
(cpu-wa column).
My cache dir directive looks like:
cache_dir ufs /var/spool/squid 16384 64 1024
# vmstat -d
vmstat -d
disk- ------------reads------------ ------------writes----------- -----IO------
total merged sectors ms total merged sectors ms cur sec
ram0 0 0 0 0 0 0 0 0 0 0
ram1 0 0 0 0 0 0 0 0 0 0
ram2 0 0 0 0 0 0 0 0 0 0
ram3 0 0 0 0 0 0 0 0 0 0
ram4 0 0 0 0 0 0 0 0 0 0
ram5 0 0 0 0 0 0 0 0 0 0
ram6 0 0 0 0 0 0 0 0 0 0
ram7 0 0 0 0 0 0 0 0 0 0
ram8 0 0 0 0 0 0 0 0 0 0
ram9 0 0 0 0 0 0 0 0 0 0
ram10 0 0 0 0 0 0 0 0 0 0
ram11 0 0 0 0 0 0 0 0 0 0
ram12 0 0 0 0 0 0 0 0 0 0
ram13 0 0 0 0 0 0 0 0 0 0
ram14 0 0 0 0 0 0 0 0 0 0
ram15 0 0 0 0 0 0 0 0 0 0
sda 50114 8198 1197972 239114 771044 986524 13061742 1616345 0 1239
sdb 125 1430 2383 100 3 20 184 43 0 0
sdc 547181 13909 6116481 6209599 2893943 6771249 77505040 42580590 0 8027
dm-0 6659 0 143594 45401 528574 0 4228592 1248409 0 269
dm-1 13604 0 408122 82828 883993 0 7071944 3118925 0 677
dm-2 150 0 1132 387 2 0 10 2 0 0
dm-3 36240 0 639146 173982 178529 0 1428232 540632 0 229
dm-4 164 0 1136 610 35 0 76 155 0 0
dm-5 216 0 1240 817 166439 0 332884 262910 0 185
hda 0 0 0 0 0 0 0 0 0 0
fd0 0 0 0 0 0 0 0 0 0 0
md0 0 0 0 0 0 0 0 0 0 0
If it's not an I/O wait problem then what can cause squid to use 100%
of CPU core? I tried to clear cache but after an hour or so squid
began to use as much CPU as usual (~100%).
I'm not sure but maybe it started after we enlarged our outer link
from 2Mbps to 4Mbps.
I will try to move squid cache to local disk but squid works in VMware
Virtual Infrastructure. So if I move any of virtual machine partitions
from shared to local storage I wouldn't have an ability to move squid
VM from one HA cluster node to the other ('cause local partitions on
cluster nodes are different from each other).
Regards,
Nikita.
