Hitachi

JP1 Version 12 JP1/Performance Management - Agent Option for Microsoft(R) SQL Server


3.2.1 Failover when a failure occurs on a PFM - Agent host

Organization of this subsection

(1) Overview of processing when failover occurs

The following figure shows the processing when failover occurs on a host that is running PFM - Agent for Microsoft SQL Server.

Figure 3‒3: Processing when failover occurs on the PFM - Agent host

[Figure]

If PFM - Web Console is used while PFM - Agent for Microsoft SQL Server is engaged in failover processing, the message There was no answer(-6) is displayed. When this message is displayed, wait until the failover processing is completed.

After PFM - Agent for Microsoft SQL Server has failed over, an attempt to use PFM - Web Console connects you to the PFM - Agent for Microsoft SQL Server that has started at the target node.

(2) Pending function during failover

(a) About pending function

The pending function delays processing the connection to Microsoft SQL Server for a fixed time period after PFM - Agent for Microsoft SQL Server starts.

Microsoft SQL Server recovery process on standby node can cause delay in connecting to PFM - Agent for Microsoft SQL Server databases. When pending function is used for failover, the PFM - Agent for Microsoft SQL Server connects to Microsoft SQL Server after transaction recovery process completes on the standby node.

The following figure shows the process flow when using the pending function:

Figure 3‒4:  Processing flow when the pending function is used

[Figure]

(b) Specify the pending time

To specify the pending time, you can use the following ways:

  • Set up the instance environment settings using the jpcconf inst setup command.

  • Use PFM - Web Console to change the STARTUP_PENDING property of Agent Configuration.

Specify a value in the range from 0 to 3600 (units: seconds). If you specify 0, pending is not performed. Values outside the valid range are ignored.

When failover occurs, the time needed for recovery processing on Microsoft SQL Server differs depending on the server configuration and the processing contents of the application accessing Microsoft SQL Server. Set a pending time longer than the time needed in the actual operating environment.

For information about using the jpcinssetup command to set the pending time, see 2.1.4(2) Setting up an instance environment.

(c) Precautions regarding use of the pending function

  • During pending, an attempt to connect or work with PFM - Agent for Microsoft SQL Server through PFM - Web Console will result in an error.

  • When you use the jpctool service list command during pending, do not set the status management function to disable, because the jpctool service list command will not return the status until the pending process completes

  • During pending, terminate PFM - Agent for Microsoft SQL Server from the cluster software in a cluster configuration, or from the Windows Start menu, Administrative Tools, and then Services in a non-cluster configuration. Note that regardless of whether a cluster configuration is used, executing the jpcscm stop command for a pending PFM - Agent for Microsoft SQL Server will result in an error.

  • If you change the pending value through PFM - Web Console while PFM - Agent for Microsoft SQL Server is running, your change will be applied to the operation after the next start.

  • When PFM - Agent for Microsoft SQL Server is pending, the jpctool service list command displays Starting as the status.