IBM Replication requires processor resources in support of the Capture and Apply programs and the Control Center for replication administration.
The CPU requirements for the Capture program are generally low. In a well-tuned environment, customers report that the Capture program does not impact the updating applications and requires a minimum of CPU capacity. Capture for MVS can be scheduled at a lower priority than the source applications. The Capture program will simply lag behind during periods where CPU resource is constrained.
The Capture program needs CPU resource during pruning, and this action can be deferred to times when system impact is low.
The Apply program CPU requirements can vary greatly. The main factor that affects CPU is the currency requirement of the target system. The more frequent the propagation, the higher the overhead per propagated row and the greater the CPU consumption.
The Apply program requires CPU on both the source and the target system, where they are different. For example, Apply for OS/2 could be a Distributed Database Facility (DDF) thread performing mainly SQL select, but some SQL update activity, on a DB2 for MVS system. Estimating the cost of remote threads in a planned large distribution scenario might lead to a design involving an interim staging platform, as described in "Staging Changed Data".
Replication administration can be planned for a time when impact to the source and target database systems will be minimal.
In general, the impact of the Control Center is not significant in terms of the local CPU. However, during times of intensive replication source and subscription definitions, the catalogs of the data server site are extensively searched. For large MVS sites, this can have a noticeable CPU or database system impact.
See the Hardware Requirements section in the DB2 Universal Database Quick Beginnings book for your platform to determine memory and disk requirements