Db2 in a Parallel Sysplex environment

The Parallel Sysplex® is a key example of the synergy of Db2 and the IBM® zSystems environment.

Db2 takes advantage of the Parallel Sysplex environment with its superior processing capabilities. When you have two or more processors sharing the same data, you can:

  • Maximize performance while minimizing cost
  • Improve system availability and concurrency
  • Configure your system environment more flexibly
  • Grow your system incrementally

With data sharing, applications that run on more than one Db2 subsystem can read from and write to the same set of data concurrently. This capability enables you to continuously access Db2 data, even while a node is being upgraded with new software.

Db2 subsystems that share data must belong to a Db2 data sharing group. A data sharing group is a collection of one or more Db2 subsystems that access shared Db2 data. Each Db2 subsystem that belongs to a particular data sharing group is a member of that group. All members of a group use the same shared Db2 catalog. The following figure shows an example of a data sharing group with three members.

Figure 1. A Db2 data sharing group
Begin figure description. This figure shows a data sharing group with three members. End figure description.

With a data sharing group, the number of threads that can connect to a Db2 server multiplies by the number of subsystems in the group. For example, an eight-member data sharing group can have over a million simultaneous threads connect to a Db2 server.

With data sharing, you can grow your system incrementally by adding additional central processor complexes and Db2 subsystems to the data sharing group. You do not need to move part of the workload onto another system, alleviating the need to manage copies of the data or to use distributed processing to access the data.

You can configure your environment flexibly. For example, you can tailor each z/OS® image to meet the requirements for the user set on that image. For processing that occurs during peak workload periods, you can bring up a dormant Db2 to help process the work.