On Thu, 2021-10-14 at 20:51 +0000, martin doc wrote: > > > From: Andrei Borzenkov <[email protected]>, Friday, 15 October > 2021 4:59 AM > ... > > Dampening defines delay before attributes are committed to CIB. > > Private attributes are never ever written into CIB, so dampening > > makes no sense here. Private attributes are managed by attrd > > itself and you see the latest value. > > > If you change transient attribute (without -p option) value you > > will see different values reported by > > > attrd_updater -n my_ping -Q > > > and > > > cibadmin -Q -A "//nvpair[@name='my_ping']" > > > until dampening timeout expires. > > > This applies even to deleting attribute. > > Ok, now I understand what the dampen function does. > > If I understand this correctly then this probably makes every > documented example of using ocf:pacemaker:ping with a colocation > statement wrong because the only way to see the effect of dampen is > to use a rule that references the value of pingd directly. That or > the script for ping has a major flaw with respect to dampen.
Basically ping has 2 modes of operation, with and without failure_score. Without failure_score, a rule must be used. I only recall examples showing it without failure_score and with a rule > That is when I do this: > > pcs resource create myPing ocf:pacemaker:ping host_list=192.168.1.1 > failure_score=1 > pcs resource create database ocf:heartbeat:pgsql > pcs group add pgrp myPing database > > PCS will move everything to a new node if there is even 1 ping > failure because monitor in ping doesn't look at the dampened value, > only the value of the immediate returned value. If you use failure_score. If you don't use failure_score, then the ping monitor does not fail if a ping fails. The ping monitor only sets a node attribute, which then is used in a rule. With this setup, the ping resource should be cloned on all nodes, and usually not involved in any group or constraints. > The same is true with colocation statements - if a constraint is made > with a ping resource without using a rule that references pingd then > the dampen behaviour is ignored completely. > > Is the ping'er missing something that does this: > > score=`cibadmin -Q -A "//nvpair[@name='ping']" | sed -e > 's/.*value="\([^"]*\)".*/\1/'` > > before it checks if $score is less than $OCF_RESKEY_failure_score? > > Thanks -- Ken Gaillot <[email protected]> _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
