lvs sync, unusual load

[Sebastian Vieira]

This happens on my systems as well. Running one sync daemon results in an
increase of 1.00 load avg. Both daemons:  2.00 load avg. Some time ago Horms
created a patch for ip_vs_sync.c   It basicly involves changing:

- __set_current_state(TASK_INTERRUPTIBLE);
- schedule_timeout(HZ);

for

+ ssleep(1);

Recompile kernel (and ipvsadm?) reboot and the load will be normal again.
I've tested this on six lvs's and all of them perform normally after the
patch.

regards,

Sebastian



On 11/9/06, Dean Manners <deanm at ispone.com.au> wrote:
>
> > -----Original Message-----
> > From: Horms [mailto:horms at verge.net.au]
> > Sent: Thursday, November 09, 2006 5:47 PM
> > To: Dean Manners
> > Cc: lvs-users at LinuxVirtualServer.org
> > Subject: Re: lvs sync, unusual load
> >
> > Does the load go away if you turn synchronisation off again
> > (without rebooting).  Does top show the syncrhonisation
> > kernel threads doing anything particularly unusual?
> >
> > It certainly isn't what is supposed to happen. Though I'm
> > thinking that it is probably harmless. Or in otherwords
> > interesting if you want to poke in the code, less interesting
> > if you just want to config up your servers.
> >
> > --
> > Horms
> >   H: http://www.vergenet.net/~horms/
> >   W: http://www.valinux.co.jp/en/
> >
>
> Load goes up at a slow, but consistent pace as soon as I:
>
> director01:~# ipvsadm --start-daemon=master --mcast-interface=eth1
> --syncid=0
>
> Top doesn't even register ipvs_syncmaster in its top 20.  However Iv
> noticed
> the process is in 'D' state according to ps.  From man is; "D
> uninterruptible sleep (usually IO)."
>
> director01:~# ps ax |grep ipvs
> 20212 ?        D      0:00 [ipvs_syncmaster]
>
> Is this consistent to your systems ?
>
> After stopping the daemon, without a reboot, the load slowly drops back to
> 0.00~
> director01:~# ipvsadm --stop-daemon=master
>
> Have tried mcasting off both eth1 and eth0 - same symptoms..
>
>
> Regards
> __________________________________________
> Dean Manners
>
>
> _______________________________________________
> LinuxVirtualServer.org mailing list - lvs-users at LinuxVirtualServer.org
> Send requests to lvs-users-request at LinuxVirtualServer.org
> or go to http://www.in-addr.de/mailman/listinfo/lvs-users
>