You can protect your SAP data stored on DB2 UDB for z/OS against failure by setting up a replicated standby database with IBM solutions such as:
· Geographically Dispersed Parallel Sysplex (GDPS), also called "Geoplex"
· DB2 Tracker Site
The site where the database server is initially started is known as the "primary site" and the site where the database is replicated as the "standby site". In IBM documentation these sites are called:
· "Primary" and "tracker" (for DB2 Tracker Site)
· "Production" and "recovery" (for Geographically Dispersed Parallel Sysplex).
You can integrate all the replicated standby databases discussed in this section with the SAP system.
DB2 UDB for z/OS can be synchronously and asynchronously replicated to protect against database failure, as follows:
· Synchronous database replication provides a consistent copy of the data on the standby site. For SAP applications, this means that the database server on the standby site contains all updates until a specific point in time. Since the data on the standby site is consistent, the application can be emergency restarted in the standby location without having to perform time-consuming data replication. However, application performance can be affected by the replication.
Geographically Dispersed Parallel Sysplex uses synchronous database replication. For more information, see Synchronous Replication of DB2 UDB for z/OS.
· Asynchronous database replication has no performance impact on most applications, but updates that are not copied to the standby system before the failure are lost. Therefore, asynchronous recovery means that the database is less up-to-date than synchronous recovery.
DB2 Tracker Site uses asynchronous database replication. For more information, see Asynchronous Replication of DB2 UDB for z/OS.
For more information see the following IBM documentation:
· DB2 for z/OS Version 8 Administration Guide
· PLANNING FOR IBM REMOTE COPY (SG24-2595-00)
· RAMAC Virtual Array: Implementing Peer-to-Peer Remote Copy(SG24-5338-00)
· Geographically Dispersed Parallel Sysplex: the S/390 Multi-site Application Availability Solution (GF22-5063-00)