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Hello,
On 11 Oct 2001, Andreas J. Koenig wrote:
> The CPU usage of my LVS director worries me and I'd ask for advice for
> tuning parameters. Or any other advice what might be causing the high
> CPU usage. ipvsadm shows the number of connections isn't really high
> (250 active, 2100 inactive), but vmstat shows system's CPU usage is
The number of connections is not so meaningful but the traffic
is.
> >50%. The CPU is a 700MHz Celeron. I'm running DR, kernel 2.4.5-ac8
> and I haven't upgraded for a while. Would upgrading improve the
> situation?
>
> # ipvsadm -Ln # IP addresses censored
> IP Virtual Server version 0.8.0 (size=131072)
> Prot LocalAddress:Port Scheduler Flags
> -> RemoteAddress:Port Forward Weight ActiveConn InActConn
> TCP XX.XX.XX.190:443 wrr
> -> XX.XX.XX.181:443 Route 100 0 0
> TCP XX.XX.XX.190:80 wrr
> -> XX.XX.XX.182:80 Route 7 25 151
> -> XX.XX.XX.181:80 Route 7 14 153
> -> XX.XX.XX.180:80 Route 86 208 1836
>
> # vmstat 3
> procs memory swap io system
> cpu
> r b w swpd free buff cache si so bi bo in cs us sy
> id
> 1 0 1 43496 11256 184536 38580 1 0 1 0 655 100 6 53
> 41
> 0 0 0 43496 11248 184536 38580 0 0 0 63 729 110 1 57
> 42
> 0 0 0 43496 11236 184536 38580 0 0 0 9 685 107 2 56
> 42
> 0 0 1 43496 11232 184536 38580 0 0 0 0 592 97 1 57
> 42
> 0 0 0 43496 11228 184536 38580 0 0 0 16 586 108 1 56
> 42
> 0 0 0 43496 11220 184536 38580 0 0 1 9 705 102 1 56
> 43
> 0 0 0 43496 11208 184536 38580 0 0 0 0 729 104 3 57
> 41
And what I see is a low number of interrupts, something like
500 packets/sec ? And there is mostly system time, no user time. Check
for processes dealing with many files in one dir (ext2) or similar.
But there is no block i/o. May be there are processes that waste too
much system time, for example, cycling in syscalls. Check with top.
The last step is to update the kernel or to change the hardware. If the
most suspected is LVS then your CPU does not behave like a 700MHz one,
may be as 486. Or may be you have ISA NIC(s) :)
> # uptime
> 9:11am up 40 days, 17:14, 3 users, load average: 0.00, 0.00, 0.00
It is possible one running process (not detected in loadave)
to make the problems.
> Thanks,
Regards
--
Julian Anastasov <ja@xxxxxx>
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