High Availability for the Data Processing Server

Various processes are assigned to the gateway and data processing servers. Each process is responsible for running specific services. You can use the JMX console to view the services running on the OMi servers or on a specific server, such as the data processing server.

To view services via the JMX Web console:

1. In a web browser on the data processing server, open: https://localhost:29000

   When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

2. In the Topaz section, select service=hac-manager.

3. Under java.lang.String listAllAssignments() from the database, click Invoke.

   If you want to view the services of a specific server, such as the data processing server, enter the name of the server in the parameter value. If you want to view all services, leave the parameter value for the server name empty.

The processes running on the server are displayed in a table. The JMX online table contains the following columns:

The data processing server services that can be managed by HAC are described in the following table, including:

• Name of the process in JVM

• Name the High Availability Controller (HAC) uses for the process

• The services running on the process

• A description of the process

You can configure automatic reassignment of services running on a primary data processing server to a backup data processing server. To configure the automatic reassignment of services running on a primary data processing server to a backup data processing server, you must:

1. Define a backup data processing server in the JMX console:

   1. In a web browser on the data processing server, open: https://localhost:29000

      When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

   2. In the Topaz section, select service=hac-backup.

   3. Locate addBackupServer and enter the following values:

      • primaryServerName. The name of the primary server.

      • backupServerName. The name of the backup server.

      Use the machine name (not the FQDN) for both these parameters. If you are unsure of the machine name, you can use the listservers method described below to retrieve the name of the machines already configured.

   4. Click Invoke.

   To remove a backup server:

   1. In a web browser on the data processing server, open: https://localhost:29000

      When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

   2. In the Topaz section, select service=hac-backup.

   3. Locate removeBackupServer and enter the following value:

      primaryServerName. The name of the primary server for which you are removing the backup server.

   4. Click Invoke.

   To view your high availability configuration:

   1. In a web browser on the data processing server, open: https://localhost:29000

      When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

   2. In the Topaz section, select service=hac-backup.

   3. Locate listservers and click Invoke.

   The result displays a list of Servers and Backup Servers. If there are no backup servers defined or if high availability is not enabled, you get a message saying automatic failover is disabled.

2. Enable automatic failover.

   You enable automatic failover using the Infrastructure Settings or the JMX console.

   To enable automatic failover in Infrastructure Settings:

   1. Navigate to:

      Administration > Setup and Maintenance > Infrastructure Settings

      Alternatively, click Infrastructure Settings.

   2. Choose Foundations, select High Availability Controller, and locate the Automatic Failover Enabled entry in the General Properties table.

   3. Modify the value to true. The change takes effect immediately.

   4. Specify the other parameters in the table according to your needs. The details of each parameter are in the table.

   To enable automatic failover in the JMX console:

   1. In a web browser on the data processing server, open: https://localhost:29000

      When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

   2. In the Topaz section, select service=hac-backup.

   3. Locate void setAutomaticFailoverEnabled (), select True, and click Invoke.

   You can also use the JMX console to check whether high availability is enabled:

   1. In a web browser on the data processing server, open: https://localhost:29000

      When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

   2. In the Topaz section, select service=hac-backup.

   3. Locate void getAutomaticFailoverEnabled (), click Invoke.

   Note Once services are automatically switched to the backup server, the backup server becomes the new primary server. To prevent OMi services from automatically moving to the backup server after a restart, shut down the backup server before the primary server. When enabling OMi, enable the primary server and verify that all services have started before enabling the backup server. If your backup server takes over as primary server, but you want your original primary server to be reinstated as primary server (for example, because it has more resources), then you can manually switch them.

You can move services between data processing servers as server availability and resource issues arise. Reassigning services can also limit downtime during maintenance of the data processing servers.

You do not have to have high availability enabled to perform this procedure and the source and destination servers do not have to have been configured for high availability.

To use the JMX console to reassign services between data processing servers:

1. In a web browser on the data processing server, open: https://localhost:29000

   When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

2. In the Topaz section, select service=hac-backup.

3. Locate moveServices() and enter the following values:

   • customerId. The customer ID for an OMi installation is 1.

   • srcServer. The name of the source server from where you are moving services.

   • dstServer. The name of the destination server to where you are moving the services.

     Use the machine name for both these parameters. If you are unsure of the machine name, you can use the listservers method described above to retrieve the name of the machines already configured.

   • groupName. Leave this parameter value blank.

4. Click Invoke. All services running on the source server are moved to the destination server.

5. Restart the online engine (MARBLE) processes after moving them to the destination server to ensure that the model remains synchronized.

   To restart the Marble processes, run the following command:

   Linux: /opt/HP/BSM/bin/marble_supervisor_shutdown.sh

   Windows: <OMi_HOME>\bin\marble_supervisor_shutdown.bat

   The Marble processes then automatically restart after being shut down. This can take a few minutes.

• Manually Reassigning Services. You can manually reassign services running on a primary data processing server to a backup data processing server should it be necessary. Since a service can only be active on one data processing server, you must either remove the existing assignment, or make it inactive, before reassigning the service to a different data processing server.

  To reassign a service, you can either add a new assignment, or activate a previously defined, but inactive, assignment.

  Tip You can check that services have been reassigned, activated, or inactivated correctly by viewing the service status in the JMX web console. For details, see Services Assigned to the Server.

• Removing a Service’s Assignment. Removing a service’s assignment deletes the entry from the HA_TASKS table in the management database so that it must be added as a new assignment if you wish to use it again in the future.

  To remove a service’s current assignment:

  1. In a web browser on the data processing server, open: https://localhost:29000

     When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

  2. In the Topaz section, click service=hac-manager.

  3. Under removeAssignment(), enter the following data:

     • customer_id. The customer ID for an OMi system is 1.

     • serviceName. The name of the service for which you are removing the current assignment.

     • serverName. The name of the data processing server to which the service is currently assigned.

     • processName. The name of the process; see also Services Assigned to the Server.

  4. Click Invoke. The assignment for the service is removed from the specified data processing server.

• Changing the Status of an Assigned Service. You can leave the assignment of a service to a specific data processing server in the HA_TASKS table in the management database, but make it active or inactive by changing its assigned value.

  To change the assigned value of an existing assignment:

  1. In a web browser on the data processing server, open: https://localhost:29000

     When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

  2. In the Topaz section, click service=hac-manager.

  3. Under changeAssignment(), enter the following data:

     • customerId. The customer ID for an OMi installation is 1.

     • serviceName. The name of the service for which you are changing the assignment value.

     • serverName. The name of the data processing server to which the service is assigned.

     • processName. The name of the process; see also Services Assigned to the Server.

     • assignValue. The assigned value for the assignment. Any number between -9 and 9 is valid. The value 1 makes the assignment active and any other number makes it inactive.

  4. Click Invoke. The assignment for the service is changed according to the assignValue entered.

• Adding an Assignment for a Service. You can add an assignment for a service to a specific data processing server and either activate it immediately, or keep it inactive until needed. This is useful when working with a primary and a backup data processing server. Assignments for all the services can be created for each server, with the assignments to the primary data processing server being active, and the assignments to the backup data processing server being inactive.

  To add a new assignment for a service:

  1. In a web browser on the data processing server, open: https://localhost:29000

     When prompted, enter the JMX console authentication credentials (if you do not have these credentials, contact your system administrator).

  2. In the Topaz section, click service=hac-manager.

  3. Under addAssignment(), enter the following data:

     • customer_id. The ID of the customer for which the service is to be assigned. The customer ID for an OMi system is 1.

     • serviceName. The name of the service you are assigning.

     • serverName. The name of the new data processing server to which the service is being assigned.

     • processName. The name of the process; see also Services Assigned to the Server.

     • assignValue. The assigned value for the assignment. Any number between -9 and 9 is valid. The value 1 makes the assignment active and any other number makes it inactive.

  4. Click Invoke. The assignment for the service is added for the specified data processing server.

If both of the data processing servers are stopped, or crash, the server that was stopped last must be restarted first. If the server that was stopped last cannot be restarted, you can use the following command to switch the live bus to the other server, and then start that server. Run the following command on the live bus server (the server that was stopped last):

<OMi_HOME>/opr/support/opr-support-utils.[bat|sh] -resetserver

After using this option, the other data processing server will start as the live bus server, and will continue with buffered JMS messages from the last backed up data that had been replicated. Any data not yet replicated is lost.