RE: Clustered xPLHal

["Ian Lowe" <ian@xxxxxxxxxxxxxxxxxx>]

Absolutely - John B looked at this in some detail, and I believe that
some of the basic elements required have been added to the XHCP Protocol
(which uses TCP rather than UDP, same port) in preparation for this sort
of environment.

Ian.

-----Original Message-----
From: g8kmh [mailto:lehane@xxxxxxx]
Sent: 22 December 2004 18:10
To: ukha_xpl@xxxxxxx
Subject: [ukha_xpl] Clustered xPLHal



With xPLHal becoming more used and, therefore, more critical to the
operation of HA systems, does anyone think that a failover cluster
arrangement might be useful?

Some of the basics already exist - heartbeats, globals, etc.

I was thinking of an active/passive arrangement where the active
performs the tasks (scripts/determinators) and the passive is in
standby. Along with a heartbeat the active would send the current values
of the Globals. If after a preset period the standby has not seen the
heartbeats it takes over - at the same time announcing it has become
active. This is a typical 'shared none' arrangement with a single
heartbeat channel. Failback would be manual.

Any thoughts?

Merry Christmas!
Lehane