How to interface to Zookeeper, etcd or Corosync ...

[Richard Sharpe]

I wanted to engage in some discussion around how to interface to those
three clustering engines.

My experience is that while etcd could be accessed from each smbd,
Zookeeper cannot be so easily accessed because its client places a
connection and this does not work across so well.

I think one could keep the smb.conf in either of those clustered
name-value stores but one could also keep some tdbs with some effort.

I suspect that I would need to use something like dbwrap as the
interface to all of this, and I have used dbwrap before to interface
to ZooKeeper, but it was done via a central ZooKeeper server on each
node.

That being the case, it would seem to be ideal to have a separate
process, perhaps the master smbd that interfaces to each of these
services and is accessed via Samba's messaging service.

It would seem to need to:

1. Monitor loss of connection to the quorum and kill all child smbds
if that occurs,
2. Provide the ability to read and set records in the key-value store
3. Provide a lock and read or lock and write service, with or without waiting.

Does this sound reasonable.

At the 10,650 foot level, I want something other than CTDB as the
cluster-wide key-value store ...

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)