3.6.0 MxDB for SQL Server Installation and Administration Guide (5697-7088, December 2007)

Chapter 5: Configuration and Operation 68

SERIAL. This is the default setting. When a Virtual SQL Server moves

from one node to another, The following strict ordering sequence for

running Post Start and Post Stop scripts is enforced:

1. The Post Stop script is run on all nodes where the virtual server

should be inactive.

2. ClusterPulse waits for all Post Stop scripts to complete.

3. The Post Start script on the node where the virtual server is becoming

active.

PARALLEL. The strict ordering sequence for Post Stop and Post Start

scripts is not enforced. The scripts run in parallel across the matrix as a

virtual server is in transition.

The

PARALLEL configuration can speed up failover time for services that

do not depend on strict ordering of Post Start and Post Stop scripts.

Assuming that it is safe to run the scripts in parallel (which depends on

your application), this setting can also increase the chances of a successful

failover because ClusterPulse does not have to wait for the failing node to

finish running its Stop script.

Configure SQL Clients

To connect to a SQL database on a PSFS filesystem, SQL clients must

specify the fully qualified name or the IP address of the Virtual SQL

Server, plus the static TCP port number of the SQL instance associated

with the SQL database. For example, if VSQL1\Default listens on port

1433 and has the virtual IP address 99.11.14.2, clients could specify either

VSQL1\Default,1433 or 99.11.14.2,1433.

NOTE: MxDB for SQL Server needs to know the port that SQL clients will

use to access the SQL database. This means that SQL clients

cannot use dynamic port assignment.

Certain SQL applications provide their own method to specify this

information. If this is not the case for your application, you can create an

alias to simplify the amount of information that needs to be entered.