CARP performance tuning question.
peterjeremy at optushome.com.au
Thu Nov 6 02:53:46 PST 2008
Whilst I don't doubt that you have a problem, your comments don't
correlate particularly well with the data you have provided and
this makes it difficult to immediately suggest a solution.
On 2008-Nov-05 16:40:32 +0300, pluknet <pluknet at gmail.com> wrote:
>AT work we use device carp(4) under high load:
carp(4) is solely a failover mechanism. It either generates or receives
somewhat under 1pps per carp interface and the state it maintains is
basically 'master' or 'backup'. I suspect the 'load' is being caused
by pf(4), possibly in conjunction with pfsync(4).
>The problem is that the server experiences a bad interactivity (from
>70k states and very bad from 120-150k)
>i.e. when a network workload (and interrupts count) begin to increase.
>CPU states: 0.0% user, 0.0% nice, 0.4% system, 76.3% interrupt, 23.3% idle
> PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND
> 13 root 1 -44 -163 0K 8K WAIT 407:43 57.86% swi1: net
I agree that swi1 is using a significant amount of CPU but top is
still reporting >23% idle so you shouldn't be getting poor interactive
>ATM pfctl -s info shows such numbers:
>State Table Total Rate
> current entries 153972
> searches 6052078938 4800.8/s
> inserts 120373545 95.5/s
> removals 120219573 95.4/s
That shows the load on pf(4) but doesn't really reflect what the
system is doing as a whole.
>It works currently under UP, but could be rebuilt to work under SMP
>(Xeon 5130) if that helps.
Unfortunately, I don't know if this will help or not because I'm not
sure what bottleneck you are hitting.
>Can someone give hints to decrease interrupt count and to help with
>the server stability at all?
Well, you haven't actually reported what the interrupt count or
what instability you are seeing so this is a bit difficult.
Can you please provide some more information:
- output from 'uname -a'
- output from 'vmstat -i; sleep 10; vmstat -i' under load
- output from 'netstat -i'
- 10-15 seconds of output from 'netstat -i 1' under load
- What is the box doing? Is it a straight filtering router? Does it
handle NAT? Is it running apps itself (eg web, ftp, mail)?
- What speed are the interface(s) running at?
- What instability problems are you seeing?
- Please provide more details on what you mean by 'bad interactivity'.
- How complex is your pf ruleset? How many rules? Anything unusual?
- What scheduler are you using?
- What is the full output of 'pfctl -s info'?
Please excuse any delays as the result of my ISP's inability to implement
an MTA that is either RFC2821-compliant or matches their claimed behaviour.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Size: 195 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-net/attachments/20081106/b6f78398/attachment.pgp
More information about the freebsd-net