[Pacemaker] proper "dampen" value for ping resource
klaus.mailinglists at pernau.at
Fri Mar 11 07:59:02 EST 2011
I wonder what a proper value for "dampen" would be. Dampen is documented as:
# attrd_updater --help|grep dampen
-d, --delay=value The time to wait (dampening) in seconds further
So, I would read this as the delay to forward changes, e.g. to not
trigger fail-over on the first failed ping, but only after multiple
Now, the default values (and examples have):
primitive pingtest ocf:pacemaker:ping \
params host_list="..." dampen="5s" \
op monitor interval="10s"
This means, that the host is pinged 5 attempts (default), then 10
seconds pause, then another 5 pings , then again 10 seconds pause.
Thus, I would think that if pinging fails (5 of 5 fails), then this is
an "error", but failvoer happens 5 seconds later (dampen). Is this
correct? If yes, then it would make more sense to adapt the examples and
increase the dampen value to cover at least 2 failed ping attempts (5*2s
+ 10s + 5*2s = 30s) or shorten the attempts and interval, e.g.:
attempts=1, interval=2s, dampen=5.
If I am completely wrong, what behavior is really caused by "dampen"?
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