[Linux-cluster] RHCS resource agent: status interval vs. monitor interval

[Ofer Inbar]

My questions last month were:

1. Why do we have both "monitor" and "status" actions in the meta-data

2. How are the "timeout" and "interval" attributes actually used by rgmanager?

> > I tried to find the answer in:
> >   https://fedorahosted.org/cluster/wiki/ResourceActions
> >   http://www.opencf.org/cgi-bin/viewcvs.cgi/*checkout*/specs/ra/resource-agent-api.txt?rev=1.10

... at the time, those docs didn't help much in answering these questions.

Today, I found lon on #linux-cluster on freenode IRC and asked about
it.  He updated the ResourceActions page on the wiki.  It now contains
a lot more information about this.

BTW, the answer to #1 is that the monitor action is part of the OCF
standard, but rgmanager ignores it and uses the status action instead.
That's now explained on that wiki page.

One thing that isn't yet explained there: the status interval clock
begins after the most recent status action has *completed*, so add
the time taken by a status check to the interval.  Also, rgmanager
checks about every 10 seconds whether any status intervals have expired
and need re-checking, so every interval is effectively rounded up to
the next multiple of 10.

For example, if:
 - status interval = 40
 - status check takes 15 seconds to complete

You'll get a new status check every 60 seconds.
  -- Cos