CTDB ipreallocated event handling

[Bjoern Baumbach]

Hi Martin,

I would like to understand the handling and the of the ipreallocated
event and the things connected with it. I've a few notes and questions.

According to the README in the events.d folder, the event is triggered
after "releaseip", "takeip" and "updateip" events.
But at the end of the file I read the following:

* The "ipreallocated" event is run on all nodes.  It is even run if no
  "takeip", "releaseip" or "updateip" events were triggered.

This sounds for me, that one of the statements is not correct :-)

As far as I can see, the event is triggered every time, when the ip
address allocation could have been changed - and this is nice. We should
specify the exact behaviour in the 'ipreallocated' passage.


The next issue is the usage of the service_reconfigure() function in the
event scripts.
According to the README, "an explicit ipreallocated event handler is
usually not necessary", because the service_reconfigure() function "will
be implicitly run before the ipreallocated event".

Who does call the service_reconfigure() function and why this is done
before the ipreallocated event?

The 60.nfs event script has a ipreallocated handler which calls the
ctdb_service_reconfigure() function explicitly. Is this fine? Wouldn't
this call service_reconfigure() twice? The first time by the magic call
before the ipreallocated event and the second with the ipreallocated
event? Or is the ipreallocated event ignored, because the first magic
call un-sets the "need reconfigure"-flag?

I would be glad if you can help me to clarify this :-)

Best regards,
Björn

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