Using Application Primary/Backup Failover
Unified Assurance provides 1-1 failover capability within most applications. The documentation for each application can be checked to see if it supports failover. However, this capability is handled differently for scheduled jobs and services.
For scheduled jobs, the broker with the backup job checks to see if the primary broker is online, and if so, the backup job will not be started. If the primary broker is offline or otherwise unreachable, the backup job will be started. This means that disabling the primary job is not enough for a backup job to be started.
For services, the broker with the backup service will check to see if the primary service is running, and if so, the backup service will be left in a "sleeping" state. If the primary service is not running, the backup service will start processing data. This means that manually stopping the primary service will make the backup service start.
This chapter explains how to enable 1-1 failover configuration. The same procedure is used for both services and scheduled jobs.
Dependencies
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A Primary/Backup pairing will only work on servers that have been configured as a redundant pair.
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The application must be available on all servers that runs the paired application.
Create Failover
To create a failover job or service:
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Navigate to the Jobs or Services interface to add or clone a job or service and modify it to create the primary job or service for which you need to create failover.
To open the Services interface, from the main navigation menu, select Configuration, then Broker Control, and then Services.
To open the Jobs interface, from the main navigation menu, select Configuration, then Broker Control, and then Jobs.
Note:
While setting up the primary job or service, consider the following configurations:
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Set Failover Type to Primary.
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Set Status to Enabled.
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Ensure to set the correct amount of threads. Do not exceed 8 * total number of cores for total threads. The number of DB threads created will be 1/3 this number unless manually set to a different value.
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Start the primary application.
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Create a clone of the primary scheduled job or service with the following configurations:
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Set Server to the Unified Assurance server that runs the backup service or job.
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Set Failover Type to Redundant/Backup.
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Set Status to Enabled.
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Start the backup application.
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Navigate to the Failover Service States UI and validate the failover status on the Primary and Backup brokers.
To open the Failover Service States interface, from the main navigation menu, select Configuration, then Broker Control, and then Failover Service States.
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Navigate to the Logs UI and verify application functionality and review the application logs to see if any errors occur. The log files can be viewed in the CLI in the $A1BASEDIR/logs/ directory, or from the UI.