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2.4 Rolling maintenance
Within one DB2 data sharing group, different DB2 maintenance levels can be contained
temporarily. Consequently, you can upgrade the DB2 servers of a data sharing group one
after the other without interrupting the SAP application. In addition to maintaining the DB2
levels this way, the z/OS release levels can also vary within one sysplex and, therefore, rolling
upgrades can be applied.
2.5 Single points of failure
Tivoli
Tivoli
System
Automation
Non-SAP
Non-SAP
(WebSphere,
(WebSphere,
CICS, IMS)
In an SAP environment, dialog instances can be added and removed without causing system
outages, because the load balancing mechanisms of the message server or the SAP
WebDispatcher automatically route requests to available servers. The database server and
the SCS are the SPOFs, which also apply to the storage subsystems.
To minimize the impact of outages concerning such SPOFs, redundancy must be established
for these components. Redundancy means running one or more (standby) servers that provide
the possibility for failover and restart of the SPOF services independently of another server.
Figure 2-5 shows the high-end business continuity configuration for an SAP environment.
Within this setup, redundant components are in two different data centers. The concepts and
techniques employed here ensure that every component has a backup in another data center
that can automatically take over if an individual component or a whole site fails.
Data Center 1 Data Center 2
SAP SAP NetWeaver
Application Server
SAP Business Suite
DS8000
primary
Flash
Copy
GPFS mirroring
GDPS
Disaster Recovery
IBM System z IBM
Coupling Facility
IBM System z
DB2
DB2
SAP SAP Central
Central
Services
Services
z/OS z/OSWorkload Workload Manager, z/OS Security
Server, Server, Network Network File File System,
System,
Tivoli Tivoli System System Automation
Automation
IBM Parallel Sysplex &
DB2 Data Sharing
(Global) Metro Mirror/
Remote Pair FlashCopy
Figure 2-5 High-end business continuity configuration for SAP
SAP Central
Services
18 Running SAP Solutions with IBM DB2 10 for z/OS on the IBM zEnterprise System
CF
SAP SAP NetWeaver
NetWeaver
Application Server
SAP Business Suite
DB2
DB2
z/OS z/OS Workload WorkloadManager, Manager, z/OS z/OS Security
Security
Server, Server, Network Network File File System,
System,
Tivoli Tivoli System System Automation
Automation
DS8000
secondary Flash
Copy
Tivoli
Tivoli
System
System
Automation
Non-SAP
Non-SAP
(WebSphere,
(WebSphere,
CICS, CICS, IMS)
IMS)