DB2 for Linux, UNIX, and Windows – High Availability Disaster Recovery (HADR) 
High Availability Disaster Recovery (HADR) is a replication feature of DB2 to make the database server highly available (shared nothing approach).
In this scenario, you have two separate DB2 database servers:
Primary database server
Standby database server
Both servers are kept in sync. In the case of a failure, the standby database server takes over the workload.
Note
HADR is only a replication feature. There is no failure detection and no automation facilities.
Process
To monitor the database servers and to automate the takeover in case of a failure, you have to set up a cluster management software to monitor the database servers and to automate the takeover in case of a failure.
Note
For AIX, Linux, and Solaris SPARC, we recommend that you use SA MP as cluster management solution. For more information, see the document IBM DB2 High Availability Solution: IBM Tivoli System Automation for Multiplatforms at:
http://service.sap.com/instguidesnw 
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