SAP Basis Tech Supports

Symptom

This SAP Note describes how you can set up a DB2 data sharing group so that two or more members are running on the identical z/OS LPAR.

Other terms

HA Failover z/OS System z DB2 data sharing LPAR

Reason and Prerequisites

Your SAP system is running with DB2 in data sharing mode and DB2 Connect as database client. For remote clients that do not run on z/OS, DB2 clients use the DB2 location name, host name and port number to connect to the DB2 server. The location name and port number are identical for all members of a DB2 data sharing group.

Solution

This section describes the two approaches that you can follow to enable two or more DB2 members to run on the same z/OS LPAR and at the same time to make sure that the connections created by SAP app server are directed to the intended member.
First approach:
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You have to define a DDF location alias and DDF port alias that is unique for each DB2 member. For SAP ABAP, you then use the different port aliases in the connect.ini configuration file. For SAP Java, you use the different port aliases in the JDBC connection attribute clientRerouteAlternatePortNumber.
The following is an example how you can use the DB2 utility DSNJU003 to specify the DDF settings.
These are sample settings:
//DSNTLOG EXEC PGM=DSNJU003
//*
//STEPLIB DD DISP=SHR,DSN=
//SYSUT1 DD DISP=OLD,DSN=
//SYSUT2 DD DISP=OLD,DSN=
//SYSPRINT DD SYSOUT=*
//SYSUDUMP DD SYSOUT=*
//SYSIN DD *
DDF LOCATION=DDFDHA,ALIAS=DHAALIAS:8188,
LUNAME=SAPD0001,PORT=8162,RESPORT=8163
Second approach:
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Use the TCP PORT statement in the z/OS TCPIP profile to assign a different IP address to the DDF address spaces of the DB2 members. It is crucial to assign this IP address to both the SQL port (DSNJU003 option PORT) and Resync port (DSNJU003 option RESPORT) of DDF.
Example: PORT ……
8188 TCP DHA1DIST BIND 192.168.216.201
8188 TCP DHA2DIST BIND 192.168.216.202
Specify the unique IP address in the JDBC connection property clientRerouteAlternateServername.
For details on the TCP PORT statement, see
http://publib.boulder.ibm.com/infocenter/zos/v1r9/index.jsp?topic=/com.ibm.zos.r9.halz001/portst.htm