Obtaining Tuning and Capacity Planning Information

Note: The information in this topic is intended for use by system programmers in tuning and planning a sysplex. The programmer designing a multisystem application does not need this information.

Installations running multisystem applications that use the XCF signaling services need data for tuning the sysplex, and data for planning the capacity of the sysplex. XCF accumulates information during sysplex processing, and maintains that information. The Resource Measurement Facility™ (RMF™) collects, and produces reports based on, this data. For more information on the reports that RMF produces for tuning a sysplex, see z/OS MVS Setting Up a Sysplex and z/OS RMF User's Guide.

Authorized routines can also obtain tuning and capacity planning information by issuing the IXCMG macro. The information provided by the IXCMG macro is mapped by the IXCYAMDA mapping macro.

When you code the IXCMG macro, you specify what type of information you want (TYPE parameter), where you want the information placed (DATAAREA parameter), and which system in the sysplex you want to gather the information from (GATHERFROM parameter). When you code the DATAAREA parameter, you must also code the DATALEN parameter to tell XCF the size of the area that you provided. If you do not allow enough space, XCF does the following:

Fills up the space you did provide
Lets you know how much space you should have provided
Sets a reason code of X'4'.