[DRBD-user] Protocol A Pending

J.R. Lillard jlillard at ghfllc.com
Tue Jul 3 00:00:51 CEST 2012

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.


On Mon, Jun 25, 2012 at 2:10 PM, Lars Ellenberg
<lars.ellenberg at linbit.com>wrote:

> On Fri, Jun 22, 2012 at 02:38:07PM -0500, J.R. Lillard wrote:
> > Witnessed another bandwidth spike that slowed my stacked layer down.
> >
> > 10: cs:Connected ro:Primary/Secondary ds:UpToDate/UpToDate A r-----
> >     ns:192538032 nr:0 dw:599650316 dr:1701817080 al:4481613 bm:43214 lo:1
> > pe:2050 ua:0 ap:2049 ep:1 wo:f oos:0
>
> You want to increase your max-buffers.
>

I set max-buffers and max-epoch-size to 8000 but I'm still having issues.
 r1-U filled up almost 75% of it's 200M proxy buffer.  During that time the
pe for r1-U kept climbing and all the disk writes were put on hold until it
could start catching up.  I can tell this because my virtual machines all
freeze up and write latency reported from ESXi skyrockets as well.  I'm
still wondering if I'm not understanding some fundamental part of DRBD or
Proxy.  I am expecting my third node to never affect the performance of my
primary nodes unless the Proxy buffers filled up completely.  Is that not
the case?


> And have a look at the other hints on drbd performance tuning.
>

I did but nothing else seems to apply.


> Cheers,
>
>         Lars
>
>
> >         resync: used:0/61 hits:3274 misses:165 starving:0 dirty:0
> > changed:165
> >         act_log: used:135/3833 hits:788561 misses:25007 starving:0
> dirty:28
> > changed:24979
> >
> > On Fri, Jun 22, 2012 at 8:24 AM, J.R. Lillard <jlillard at ghfllc.com>
> wrote:
> >
> > > My starving count was pretty high.  I maxed out my al-extents and will
> see
> > > if that helps.  Thanks.
> > >
> > >
> > > On Fri, Jun 22, 2012 at 4:22 AM, Andreas Kurz <andreas at hastexo.com>
> wrote:
> > >
> > >> On 06/20/2012 11:51 PM, J.R. Lillard wrote:
> > >> > I have a lower-level setup on Protocol C and a stacked layer of
> Protocol
> > >> > A going through Proxy over a WAN.  There are times when my disk
> activity
> > >> > spikes causing the Proxy buffers to fill up a bit.  While this is
> > >> > happening the Pending count on my stacked resources goes up and
> causes
> > >> > my access to those resources to slow down.  Is this normal?  I
> thought
> > >> > with Protocol A as soon as my local write was finished things would
> > >> > continue.
> > >>
> > >> You checked that you are not running out of activity log extents for
> the
> > >> stacked resource?
> > >>
> > >> Do an: echo 1 >/sys/module/drbd/parameters/proc_details
> > >>
> > >> ... and have a look at "starving" counter in /proc/drbd ... should
> > >> ideally be 0 and definitely not increasing regularly. If it does,
> > >> increase the al-extents value for the stacked resource (max is 3833 in
> > >> drbd 8.3 ... IIRC)
> > >>
> > >> Regards,
> > >> Andreas
> > >>
> > >> --
> > >> Need help with DRBD?
> > >> http://www.hastexo.com/now
> > >>
> > >> >
> > >> > --
> > >> > J.R. Lillard
> > >> > System / Network Admin
> > >> > Web Programmer
> > >> > Golden Heritage Foods
> > >> > 120 Santa Fe St.
> > >> > Hillsboro, KS  67063
> > >> >
> > >> >
> > >> >
> > >> > _______________________________________________
> > >> > drbd-user mailing list
> > >> > drbd-user at lists.linbit.com
> > >> > http://lists.linbit.com/mailman/listinfo/drbd-user
> > >> >
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> _______________________________________________
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> > >> http://lists.linbit.com/mailman/listinfo/drbd-user
> > >>
> > >>
> > >
> > >
> > > --
> > > J.R. Lillard
> > > System / Network Admin
> > > Web Programmer
> > > Golden Heritage Foods
> > > 120 Santa Fe St.
> > > Hillsboro, KS  67063
> > >
> > >
> >
> >
> > --
> > J.R. Lillard
> > System / Network Admin
> > Web Programmer
> > Golden Heritage Foods
> > 120 Santa Fe St.
> > Hillsboro, KS  67063
>
> > _______________________________________________
> > drbd-user mailing list
> > drbd-user at lists.linbit.com
> > http://lists.linbit.com/mailman/listinfo/drbd-user
>
>
> --
> : Lars Ellenberg
> : LINBIT | Your Way to High Availability
> : DRBD/HA support and consulting http://www.linbit.com
>
> DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.
> __
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-- 
J.R. Lillard
System / Network Admin
Web Programmer
Golden Heritage Foods
120 Santa Fe St.
Hillsboro, KS  67063
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