[Linux-cluster] dynamically reconfigure qdiskd heuristic: possible?

[Lon Hohberger]

On Mon, 2009-04-27 at 13:47 +0200, Gianluca Cecchi wrote:
> Is there any command for this? I'm on rh el 5.3
> For example if I want change the line
> 
> <heuristic interval="2" program="ping -c1 -w1 10.4.5.250" score="1" tko="3"/>
> 
> so that it becomes
> <heuristic interval="2" program="ping -c1 -w1 10.4.5.250" score="1" tko="30"/>
> 
> It seems that with
> 1) ccs_tool update /etc/cluster/cluster.conf
> 2) cman_tool version -r new_vers_number
> 
> it doesn't work dynamically....

Correct, heuristics and timings require a restart.  STABLE3 allows
reconfiguring some things dynamically, but not heuristics because
changing them is very hard to synchronize cluster-wide (particularly
when for example qdiskd is blocked waiting for a write or something).

Instead, start up the cluster (on all nodes) make the update, then
restart qdiskd on each node in turn.

-- Lon