SAP R/3 on DB2 for OS/390: Database Availability Considerations
An IBM Redbooks publication
Note: This is publication is now archived. For reference only.
This IBM Redbooks publication describes availability procedures for the database of an SAP R/3 4.6B installation that uses DB2 UDB for OS/390 as the SAP R/3 database server. The book is one of a series that focuses on SAP R/3 when DB2 UDB for OS/390 is used as a database server.
This book reflects the considerable development effort, both by SAP AG and by IBM, that has been focused on the area of database availability due to the reliance on SAP R/3 by customers who expect a high degree of availability, in some cases 24 hours per day, every day of the year.
Since the subject of this book is database availability, we concentrate on the database that applies to this solution, DB2 UDB for OS/390. Much effort was spent on looking at data sharing with DB2 to see how that improves availability of the database, and to investigate how it is defined and used. We also review database administrative activity that must be periodically run, to see how that can be done with as little disruption as possible.
We also investigate the Split Mirror Backup Facility as defined by SAP R/3 and implemented with DB2 UDB for OS/390. A particular area of interest is the minimizing of time to perform a backup, since this regularly scheduled activity can be disruptive. Obviously, no discussion of backup is complete without a discussion of using the backups for recovery, so we address the subjects of full and partial recovery as well.
Our environment included an OS/390 installation on Parallel Sysplex, so we also document specific Parallel Sysplex configuration examples and functions that apply to SAP R/3, and present the results of the limited testing we performed on those functions.
Ch. 1 Introduction
Ch. 2 SAP R/3 availability benefits from S/390
Ch. 3 Database high availability for SAP R/3
Ch. 4 Database administration - reducing unplanned outages
Ch. 5 Creating database backups
App. A Availability test scenarios
App. B SAPNet R/3 - Notes (OSS) & Informational APARS
App. C Tracefile of the work processes after adapter failure