High Availability Disaster Recovery for IBM Db2 for Linux, UNIX, and Windows
High Availability Disaster Recovery (HADR) is a replication feature of IBM Db2 to make the database server highly available.
Architecture and Capabilities
In this scenario, you have two separate Db2 database servers:
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Primary database server
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Standby database server
Both servers are kept in sync. In the event of a failure, the standby database server takes over the workload.
As of Db2 10.1, you can have up to three standby databases with Db2 HADR. You designate one of these databases as the principal HADR standby database; any other standby databases serve as auxiliary HADR standby databases.
HADR provides the following capabilities:
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Fast fail-over in the event of unplanned outages
You can configure one HADR standby server as the target for fast fail-over.
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Rolling Db2, hardware, and operating system maintenance
You can use the SAP tools "Graceful Maintenance Tool" (SAP Note 1530812
) and "Graceful Cluster Switch" (SAP Note 1443426
) to reduce the impact of planned take-over operations on your business operations. -
Protection against a disaster
You can place one or multiple HADR standby servers in far distant locations to protect yourself against a complete loss of a site.
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Protection against logical errors
You can operate one or multiple HADR standby servers with time delayed replay. In the event of undesired changes to your data, you can connect to the standby database server that has not yet replayed the error and retrieve the data from there.
HADR is a replication feature. You can combine HADR with cluster management solutions that automate the takeover in the event of a failure. For AIX, Linux, and Solaris SPARC, we recommend that you use IBM Tivoli System Automation for Multiplatforms (SA MP) as the cluster management solution. The license to use SA MP for HA of your Db2 database server is included in your Db2 license.
More Information
For more information, see the following:
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Installation guide IBM Db2 High Availability Solution: IBM Tivoli System Automation for Multiplatforms
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IBM documentation for IBM Db2 for Linux, UNIX, and Windows: HADR Multiple standby databases
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