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By combining mySAP Business Suite and the IBM eServer zSeries, companies can gain a competitive edge through the outstanding strengths of the implementation with zSeries.
With zSeries, the industry's top-rated platform for security, reliability, manageability, and availability, SAP environments can greatly benefit from advantages such as
Some of the major benefits are explained in more detail in the following sections.
Integration of SAP with legacy applications
On zSeries an additional connectivity module has been developed to enable application connectivity between customer specific legacy applications and SAP applications. Solutions based on CICS or IMS connect directly and synchronously to SAP applications entering the SAP transaction by business APIs. Customers relying on their proven COBOL or PL/I applications are enabled to easily interact with SAP applications, exchange data or continue operations in any SAP system. For details, see the subject "SAP Connectors" in SAPNet.
DB2 and data sharing
DB2 UDB for z/OS has been engineered to exploit the zSeries architecture and z/OS operating environment, with the fundamental design objective of meeting the most stringent customer requirements.
The SAP database server running on z/OS can fully benefit from the strengths of DB2 on zSeries such as
- Designed for high volume throughput
- Virtually unlimited scalability with data sharing in Parallel Sysplex
- Database server consolidation capabilities
- Optimized for zSeries architecture
- Highest availability with Parallel Sysplex
- Processor-based data compression
- Online backup/restore and online reorganization to reduce planned outages
- Highest level of security
Major improvements with DB2 UDB for z/OS Version 8
With Version 8, DB2 has implemented more than 50 feature requests specifically to optimize for SAP solutions on zSeries. These key improvements enhance scalability, application porting, security architecture, and continuous availability. Management for very large databases is made much easier. 64-bit virtual storage support relieves virtual storage constraints and improves scalability. DB2 V8 enables many new capabilities for online schema evolution and database administration. For easier management and better cost control, DB2 V8 supports workload management and accounting based on SAP transaction codes, SAP program names, SAP batch job names, and end user IDs. This allows customers to charge IT costs individually. Moreover, highest priority can be assigned to crucial units of work, such as vital SAP transactions.
Further information on DB2 V8 features can be found in the IBM Redbooks DB2 UDB for z/OS V8 - Technical Preview, SG24-6871, and DB2 UDB for z/OS: Through the Looking Glass and What SAP Found There, SG24-7088, or at www.ibm.com/software/data/db2/os390/db2zosv8.html.
64-bit virtual addressing increases virtual storage dramatically
One of the major improvements from which SAP solutions can heavily benefit is the 64-bit virtual addressing capability of DB2 V8. This relieves virtual memory constraints and supports significantly larger buffer pools of up to 1 terabyte and more concurrent threads. It also allows greater scalability of large DB2 subsystems or members of a DB2 data sharing group to meet the demands of increasing workloads in a dynamic business environment.
Highest availability for mission-critical applications
zSeries has an expected mean time between failures of nearly 30 years and is the ideal platform for mission-critical applications where high availability is key. Based on this bullet-proof hardware platform, IBM continues to invest heavily in extending the technology leadership of the zSeries Parallel Sysplex cluster architecture. DB2 Version 8 exploits new coupling facility commands that were developed specifically for DB2 to more efficiently write groups of data pages. It improves the efficiency of DB2 data sharing, especially for an application like SAP. In addition, DB2 V8 implements a new locking protocol for data sharing to reduce locking overheads in the coupling facility and to provide greater availability.
System-level point-in-time recovery for faster recovery of entire SAP databases
Enhancements to system-level point-in-time recovery for DB2 provide improved usability, more flexibility, and faster recovery times. With DB2 V8, you can recover your data to any point in time, regardless of whether you have uncommitted units of work. As a result, data recovery time improves significantly for large SAP DB2 subsystems with thousands of tables, and potential downtime for the SAP system decreases considerably.
Multiple Components in One Database (MCOD)
zSeries offers the capability to run SAP application components including online transaction processing (OLTP) with parallel, shared data access. The DB2 data sharing mode in a Parallel Sysplex allows best-of-breed scalability and highest availability, and also provides for a superb environment ideally suited to the concept of "Multiple Components in One Database" (MCOD).
The idea of MCOD is to put several logical databases of SAP components into one physical database in order to save administration cost and provide inherently for a consistent point-in-time recovery option for all SAP components within that database. Without MCOD, restoring several logically related, but physically separate, databases to a consistent point in time can be an administrative challenge.
Using Parallel Sysplex with data sharing in this context, DB2 provides the ability to completely isolate CPU, buffer and data structure resources of the different SAP components from each other, and this way successfully prevents conflicts among these resources.
To achieve the benefits of MCOD, SAP components can be mapped to DB2 subsystems in the following ways:
- A single DB2 subsystem, which is not involved in a data sharing group, manages multiple mySAP components.
- A DB2 data sharing group manages multiple SAP components (see diagram below)
Certainly, data sharing is not a prerequisite for MCOD. However, the second option provides more flexibility without incurring the cost of data sharing overhead. With a data sharing solution, the SAP components are managed independently and have no resource conflicts. This setup comes only with DB2 and is not matched by any other database on the market.
Server consolidation with zSeries
Server consolidation capabilities are very important, in order to increase manageability and lower the total cost of ownership (TCO) of an implementation. With zSeries, the industry leading platform for server consolidation, you have outstanding options to consolidate SAP systems through means of logical partitioning on zSeries, z/VM virtualization technology and intelligent workload management.
zSeries technology with z/VM allows customers to virtualize processors, communications, storage and I/O devices, thus helping to reduce the overhead of planning, purchasing and installing new hardware to support new workloads. z/VM based server consolidation solutions may provide significant TCO savings by enabling customers to
- Only pay for what they need
(zSeries provides on demand features to dynamically activate/deactivate additional processing engines)
- Reduce the need for additional hardware by deploying virtual servers
- Cut back administration effort and staff by lowering the number of physical servers
(shared operating system and application code among virtual servers)
- Drastically decrease set-up time for new SAP application servers by exploiting z/VM cloning mechanisms
- Reduce the stack of additionally required administration software by exploiting z/VM tools.
- Bring down network costs by replacing physical network components with virtual server communication using HiperSockets, virtual LAN, virtual switches and shared network adapters.
The virtualization capabilities of z/VM are best exploited by SAP with application servers on Linux for zSeries.
SAP on Linux
SAP Linux strategy
Open Source for SAP is a trend-setting development model that enables rapid and flexible responses to technological challenges. Linux has established itself as a platform on equal footing with other enterprise operating systems for SAP applications. Linux is (besides Windows) the reference platform for SAP development. Year after year, SAP has seen a significant growth rate for the Linux-based installations. Numerous customers operate Linux application servers in conjunction with database servers based on other operating systems.
Linux for zSeries
Linux for zSeries combines the strengths of zSeries with the flexibility and openness of Linux. With its support of 64-bit virtual addressability and J2EE, it is a well-suited platform for business critical applications today and in the future. Existing UNIX/Linux skills can be leveraged, and running Linux on the zSeries Integrated Facility for Linux (IFL) processors can provide significant cost advantages.
Linux for zSeries exploits the 64-bit eServer zSeries architecture and runs on the following models:
- IBM eServer zSeries 800 (2066)
- IBM eServer zSeries 900 (2064)
- IBM eServer zSeries 990 (2084)
For more information please see the IBM eServer zSeries mainframe server home page.
SAP Web Application Server on Linux for zSeries
The SAP Web Application Server on Linux for zSeries has been generally available since May 2002. It is SAP's and IBM's strategic 64-bit implementation on zSeries. Supporting SAP NetWeaver technology, the SAP Web Application Server on Linux for zSeries is the ideal solution for server consolidation and on demand provisioning, especially when combined with the zSeries virtualization technology z/VM.
Automation of systems management
The availability of a productive SAP system is business critical and therefore requires the highest level of availability. Continuous availability combines the characteristics of high availability (the ability to avoid unplanned outages by eliminating single points of failure) and continuous operation (the ability to minimize planned outages like administrative or maintenance work) in order to provide the ability to keep the SAP system running as close to 24x365 as possible.
The objectives of the SAP high availability solution are to address the common causes of planned and unplanned outages by:
- Providing continuous availability of the SAP system to end users
- Minimizing the effects of unplanned outages
- Reducing operator errors
- Monitoring the SAP application components
- Monitoring DB2 and the operating system(s)
This solution, based on IBM Tivoli System Automation, implements the self-healing aspect of IBM's Autonomic Computing concept. It provides the means for fully automating the management of all SAP components, platform components and related products running on z/OS, UNIX, Windows, or Linux.
Automation
By automating daily operations using System Automation, there is less opportunity for error when starting or stopping software components. System Automation provides the ability to define component dependencies. It ensures that basic operations like starting or stopping of the SAP system is accomplished without requiring the operator to understand all internal dependencies and structure. The result is clearly indicated to the operator.
This solution was first implemented and tested with IBM Tivoli System Automation for OS/390 and z/OS, which is used to automate the starting, stopping, and monitoring of SAP components, and control the restart and/or takeover of failing components, thereby ensuring nearly continuous availability of the SAP system.
In the meantime, the high availability and automation solution has been extended to the Linux environment. For details see the IBM Redpaper mySAP Business Suite Managed by IBM Tivoli System Automation for Linux, REDP-3717.
Continuous operation
Continuous operation requires systems without a single point of failure. DB2 data sharing is used to remove the database server as a single point of failure. SAP's new enqueue architecture has been introduced to remove the single point of failure of SAP Central Services. Dynamic Virtual IP Addressing and NFS Server enhancements are exploited. IBM Tivoli System Automation monitors these components and restarts them immediately in case they fail.
IBM Tivoli System Automation exploiting the SAP Central Services architecture
The Central Services are critical for an SAP system. To avoid situations with the failure of SAP Central Services, an SAP system offers replication services for the critical components. With System Automation the full benefits of the new architecture can be exploited.
The concept allows a takeover of the enqueue server to another system without losing the enqueue information. System Automation recognizes a failure of an SAP component instantly and restarts it automatically. In case of the enqueue server, it is restarted on the system where the replication server is running. The restarted enqueue server rebuilds the enqueue information in a table based on the replicated data.
The ABAP and J2EE instances reconnect to the enqueue server once it is restarted. Transactions do not fail but wait until the connection is reestablished. Similar reconnection behavior applies to the message server and the gateway. Thus a failure of the Central Services is transparent to the end user and the SAP business application.
Again, System Automation also handles the transfer of the enqueue replication server to another system in the cluster, in order to be prepared for the next failure.
 Implementation structure with IBM eServer zSeries
Implementation flexibility with zSeries
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