[Linux-ha-dev] Cluster management thoughts

[Andrew Beekhof]

After a productive IRC chat with sunjd, I'd like to clarify my position 
on the management tool...

First up, I am not against having a daemon.  On the contrary, I think 
they are likely to be a necessity.  What I /am/ advocating however is 
that we first start with a higher level unification API/library that 
spans the CCM, CIB, HA, and whatever else is required.

By way of example, where the CIB API allows us to find out the status 
of all nodes in the cluster, the higher level API would process the 
CIB's result to tell you the active resources on a specific node.  Or 
where the CIB API allows you to update the CIB, the higher level would 
create a resource and add it to CIB.

My rationale here is that if we start with an API, then the number and 
types of admin clients are endless while still limiting the duplication 
of common functionality.  The same API that we use to build a SNMP 
notification daemon could also be used to build a daemon that web 
clients can connect to, or a local GUI application, or a GUI 
application that talks to a daemon, or, or... do people see where I'm 
going with this?

By going straight to the daemon I feel we are make life harder for 
ourselves... the type of daemon you need/want for a web based client 
isnt the same as for a desktop GUI application nor the same for a SNMP 
client.



The second thought is to think about migrating some of the 
configuration from ha.cf into the CIB.

Obviously there is the possibility for a chicken and egg situation here 
so not everything is appropriate to be moved, but everything that does 
is one less thing to get wrong.

Changing an option (such as the log level or whether sub-system X 
enables apphbd support) is then simply a matter of updating the CIB 
which pushes the change to all nodes.

Andrew

--
Andrew Beekhof

"No means no, and no means yes, and everything in between and all the 
rest" - TISM