[ClusterLabs] how to disable pacemaker throttle mode

[Ken Gaillot]

On Mon, 2024-02-05 at 21:30 +0100, Vladislav Bogdanov wrote:
> IIRC, there is one issue with that, is that IO load is considered a
> CPU load, so on busy storage servers you get throttling with almost
> free CPU. I may be wrong that load is calculated from loadavg, which 

Yep, it checks the 1-minute average from /proc/loadavg (it also checks
the CIB manager separately using utime/stime from /proc/PID/stat)

> is a different story at all, as it indicates the number of processes
> which are ready to consume the CPU time, including those waiting for
> IOs to complete, but that is what my mind recalls.
> 
> I easily get loadavg of 128 on iscsi storage servers with almost free
> CPU, no thermal reaction at all.
> 
> Best,
> Vlad
> 
> On February 5, 2024 19:22:11 Ken Gaillot <kgaillot at redhat.com> wrote:
> 
> > On Mon, 2024-02-05 at 18:08 +0800, hywang via Users wrote:
> > > hello, everyone:
> > > Is there any way to disable pacemaker throttle mode. If there is,
> > > where to find it?
> > > Thanks!
> > > 
> > > 
> > 
> > You can influence it via the load-threshold and node-action-limit
> > cluster options.
> > 
> > The cluster throttles when CPU usage approaches load-threshold
> > (defaulting to 80%), and limits the number of simultaneous actions
> > on a
> > node to node-action-limit (defaulting to twice the number of
> > cores).
> > 
> > The node action limit can be overridden per node by setting the
> > PCMK_node_action_limit environment variable (typically in
> > /etc/sysconfig/pacemaker, /etc/default/pacemaker, etc. depending on
> > distro).
> > -- 
> > Ken Gaillot <kgaillot at redhat.com>
> > 
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> 
> 
-- 
Ken Gaillot <kgaillot at redhat.com>