Re: [OpenVMS V7.3-2] SYSGEN> SHOW EXPECTED_VOTES vs SDA> SHOW CLUSTER

From: Keith Parris (keithparris_NOSPAM_at_yahoo.com)
Date: 09/29/05 

Date: Thu, 29 Sep 2005 21:14:11 GMT

Peter 'EPLAN' LANGSTOEGER wrote:
> I just noted a situation which I can't explain, yet.
>
> Showing the SYSGEN (active, nondynamic) parameter EXPECTED_VOTES gives
> me another value than SDA SHOW CLUSTER does.
>
> Why ? I thought they both show the same memory location. Obviously not.
> I know SYSGEN current is different (because ALPHAVMSSYS.PAR file, not mem)
> but the active ? What is the background here ?

The values which SDA> SHOW CLUSTER (and $SHOW CLUSTER/CONTINUOUS with
ADD CLUSTER,EXPECTED,VOTES,QUORUM) are from the same source: the cluster
data structures: the CLUB, along with the CSBs for each node. The CLUB
holds the cluster-wide values for things like Expected_Votes and Quorum;
these are adjusted as nodes join (and leave with the REMOVE_NODE option
to SHUTDOWN) or manual adjustments are made with SET CLUSTER,
Availability Manager, etc.

The values which F$GETSYI() and SYSGEN/SYSMAN display are the system
parameters. The cluster code picks up values of the SYSGEN parameters
VOTES and EXPECTED_VOTES at boot time and put them into the CSB for the
node, and the values in the CSBs for all the cluster nodes in turn
influence what gets set in the CLUB. Changes to the SYSGEN parameters
after boot don't affect what's already gotten moved into the CSBs or the
CLUB.