Data sharing problem diagnosis

Problem diagnosis in the data sharing environment is similar to diagnosing problems that occur in a single Db2 subsystem. The key difference is that the actions required to identify and resolve problems must be applied to more than one Db2 subsystem.

Data sharing environment

Data sharing requires a z/OS sysplex, a group of central processor complexes (CPCs) running z/OS that are connected through channel-to-channel (CTC) communications or through a coupling facility.

Data sharing uses IBM® zSystems Parallel Sysplex® technology. The sysplex technology is supported by the z/OS Cross-System Coupling Facility (XCF) and Cross-System Extended Services (XES). Cross-System Coupling Facility services allow authorized applications on one system to communicate with applications on the same system or on other systems. Cross-System Extended Services allow authorized applications or subsystems that are running in a sysplex to share data by using a coupling facility.

In Db2 data sharing, Db2 subsystems belong to a Db2 data sharing group. Each Db2 subsystem, or group member, has the same direct access to the same data as any other member of the data sharing group.

Group members share databases, a single Db2 catalog and directory, and a single z/OS ICF catalog. Each member has its own IRLM, buffer pool, EDM pool, workfiles, log, and local BSDS. The sysplex provides support for other facilities that are required for data sharing that include a global lock manager, and shared storage.