**************** ** APPENDIX B ** **************** This Appendix B describes significant RMF7130 updates to capping related information in the following MICS database files: o HARIPU - Individual Processor Activity File o HARCPU - CPU Activity File o HARVPA - PR/SM Logical Core Activity File o HARLPC - PR/SM LPAR Config/Activity File BACKGROUND ---------- At z/OS Version 2.4, IBM provides 6 different methods of capping the dispatch of logical cores for an LPAR. Some of the methods impact the dispatch of logical CP cores only. Others allow you to specify limits on the dispatching of all logical core types. Several of the capping techniques can be used simultaneously for a single LPAR. A seventh capping method, Resource Group Capping, used to control the CPU capacity available for Service Classes belonging to a Resource Group, is not discussed here. LPAR Core Related Capping Techniques ------------------------------------ The following six LPAR level capping techniques are available with z/OS Release 2.4: - Initial (hard) Capping - Defined Capacity (soft capping) - Group Defined Capacity (soft capping) - Absolute Capping - Group Absolute Capping - Absolute MSU Capping (ABSMSUCAPPING=YES/NO) Each of these capping techniques is discussed below, along with RMF7130 related updates, changes, or additions. - Initial (hard) Capping ---------------------- This was the first capping technique available, and was introduced when the only CPC core type was the general purpose CP core. Today there are many core types that can be assigned to an LPAR: CP, zIIP, IFL, and ICF. zAAPs are obsolete beginning with the z13 CPC, but because some MICS customers still have zEC12 CPCs, MICS still supports zAAP metrics. When you define an LPAR, you must specify a weight for each logical core type assigned to the LPAR. This weight determines the LPAR share of the physical cores in the CPC shared core pool, relative to other LPARs using that core type. If you choose to enable initial (hard) capping for any logical core type assigned to an LPAR, the LPAR will not be allowed to use more than its share, even when other LPARs are not fully utilizing their share of that core type. When initial (hard) capping is specified for a logical core type, no other capping techniques are allowed. Initial Capping Data Elements ----------------------------- o HARIPU and HARVPA files fffCPECT - Intvls with Partition Capping Enabled fffCPDCT - Intvls with Partition Capping Disabled fffCPCCT - Intvls with Part Capping Status Change where fff is IPU and VPA RMF7130 Updates: ---------------- fffCPECT - Intvls with Initial Capping Enabled fffCPDCT - Intvls with Initial Capping Disabled fffCPCCT - Intvls with Initial Capping Status Chg where fff is IPU and VPA - Labels updated to clarify "initial" capping - The six dictionary members (VPACP*** and IPUCP*** are obsoleted and replaced with three RMFCP*** members that describe the meaning in each of these two files. This dictionary member update does not impact reporting or analysis, it only impacts documentation. o HARCPU and HARLPC files Original "Initial Capping" Data Elements fffCPECT - Intvls with Partition Capping Enabled fffCPDCT - Intvls with Partition Capping Disabled fffCPCCT - Intvls with Part Capping Status Change where fff is CPU and LPC RMF7130 New "Initial Capping" Data Elements fffICECT - Intvls with Init CP Capping Enabled fffICDCT - Intvls with Init CP Capping Disabled fffICCCT - Intvls with Init CP Cap Status Change fffISECT - Intvls with Init zIIP Capping Enabled fffISDCT - Intvls with Init zIIP Capping Disabled fffISCCT - Intvls with Init zIIP Cap Status Change fffIZECT - Intvls with Init zAAP Capping Enabled fffIZDCT - Intvls with Init zAAP Capping Disabled fffIZCCT - Intvls with Init zAAP Cap Status Change LPCINECT - Intvls with Init IFL Capping Enabled LPCINDCT - Intvls with Init IFL Capping Disabled LPCINCCT - Intvls with Init IFL Cap Status Change LPCIIECT - Intvls with Init ICF Capping Enabled LPCIIDCT - Intvls with Init ICF Capping Disabled LPCIICCT - Intvls with Init ICF Cap Status Change where fff is CPU and LPC - Original data elements obsoleted - New data elements show initial capping status for each core type. ********************************************************* ****************** Important Note ********************* ********************************************************* * The three data elements fffCPECT, fffCPDCT, and * * fffCPCCT in the HARCPU and HARLPC file are obsoleted * * with RMF7130. If you have reports that make use of * * these three data elements, you must update the report * * code to examine the new data elements provided by * * RMF7130 to report on initial (hard) capping at the * * LPAR level. * ********************************************************** - Defined Capacity (soft capping) - Defined Group Capacity (soft capping) Defined capacity controls the dispatch of general purpose CP cores, relative to a "defined capacity" value specified in units of MSUs. Capping occurs when the 4-hour rolling average of MSU use exceeds the specified defined capacity, and the LPAR remains capped until the 4-hour rolling average drops below the defined value. Other than updating the labels of the 4-hour rolling data elements (replacing "Long-Term" with "Four-Hour"), RMF7130 did not change anything related to the data elements that characterize defined or defined group capacity. - Absolute Capacity With absolute capacity, you can specify the capacity limits of all LPAR core types in units of 1/100th of a core. Absolute Capacity Data Elements ------------------------------- o HARIPU and HARVPA files fffABSCT - Intvls with Core Use Abs Limit fffABCCT - Intvls with Core Use Abs Limit Chg where fff is IPU and VPA RMF7130 Updates: ---------------- - The data dictionary members are updated with additional information o HARCPU and HARLPC files fffCABSL - Absolute LPAR Limit for CP Core Use fffCAACT - Intvls with CP Core Use Abs Limit fffCACCT - Intvls with CP Core Use Abs Limit Chg fffSABSL - Absolute LPAR Limit for zIIP Core Use fffSAACT - Intvls with zIIP Core Use Abs Limit fffCACCT - Intvls with CP Core Use Abs Limit Chg fffSABSL - Absolute LPAR Limit for zIIP Core Use fffSAACT - Intvls with zIIP Core Use Abs Limit fffSACCT - Intvls with zIIP Core Use Abs Limit Chg fffZABSL - Absolute LPAR Limit for zAAP Core Use fffZAACT - Intvls with zAAP Core Use Abs Limit fffZACCT - Intvls with zAAP Core Use Abs Limit Chg LPCIABSL - Absolute LPAR Limit for ICF Core Use LPCIAACT - Intvls with ICF Core Use Abs Limit LPCIACCT - Intvls with ICF Core Use Abs Limit Chg LPCNABSL - Absolute LPAR Limit for IFL Core Use LPCNAACT - Intvls with IFL Core Use Abs Limit LPCNACCT - Intvls with IFL Core Use Abs Limit Chg where fff is CPU and LPC RMF7130 Updates: ---------------- - The data dictionary members are updated with additional information - Absolute Group Capacity Similar to absolute capacity, with absolute group capacity you can assign LPARs to "hardware groups", and can specify the capacity limits for each core type in units of 1/100th of a core. Managed as a group, the LPARs cannot exceed the defined capacity limits specified for each core type. RMF7130 provides initial support for absolute group capacity. Note that absolute group capacity is only available for z13 and later CPCs, so there are no absolute group capacity data elements for zAAP cores. Absolute Group Capacity Data Elements ------------------------------------- o HARIPU and HARVPA files fffABGCC - Intvls with Core Use Abs Group Change fffABGCT - Intvls with Core Use Abs Group Limit fffABGLM - Absolute Group Limit for Core Use where fff is IPU and VPA RMF7130 Updates: ---------------- - These data elements are new with RMF7130 o HARCPU and HARLPC files fffCABGL - Absolute Group Limit for CP Core Use fffCAGCC - Intvls with CP Core Use Abs Group Chg fffCAGCT - Intvls with CP Core Use Abs Group Limit fffSABGL - Absolute Group Limit for zIIP Core Use fffSAGCC - Intvls with zIIP Core Use Abs Group Chg fffSAGCT - Intvls with zIIP Core Use Abs Grp Limit LPCIABGL - Absolute Group Limit for ICF Core Use LPCIAGCC - Intvls with ICF Core Use Abs Group Chg LPCIAGCT - Intvls with ICF Core Use Abs Grp Limit LPCNABGL - Absolute Group Limit for IFL Core Use LPCNAGCC - Intvls with IFL Core Use Abs Group Chg LPCNAGCT - Intvls with IFL Core Use Abs Grp Limit where fff is CPU and LPC RMF7130 Updates: ---------------- - These data elements are new with RMF7130 - Absolute MSU Capping (ABSMSUCAPPING=YES/NO) With IBM APAR OA48688, IBM adds a new parameter for the active IEAOPTxx parmlib member for z/OS LPARs. The ABSMSUCAPPING parameter can be set to YES or NO (default is NO). ABSMSUCAPPING=YES activates absolute MSU capping. ABSMSUCAPPING=YES modifies the way defined capping and defined group capping is enforced on a z/OS LPAR. The ABSMSUCAPPING parameter only affects the dispatch of general purpose CP cores. With defined capacity (LPAR and GROUP), also known as "soft capping", LPAR capping only occurs when the 4-hour rolling average of MSU use exceeds the defined MSU limits. This allows for spikes in MSU utilization above the defined MSU limits as long as the 4-hour rolling average remains below the limit. When ABSMSUCAPPING=YES is specified, the defined capacity for an LPAR is always enforced, ignoring the 4-hour rolling average. This provides a means to strictly enforce MSU usage for an LPAR to a specific MSU limit at all times. Similarly, for LPARS participating in a defined capacity group, all LPARs in the group that have ABSMSUCAPPING=YES specified will enforce the capping at the specified group capacity limit, and ignore the 4-hour rolling group average MSU consumption. RMF7130 provides a new data element that contains the LPAR ABSMSUCAPPING parameter status: o HARCPU file CPUABMSU Intvls with LPAR Absolute MSU Capping CPUABMSU contains a one (1) in each DETAIL timespan observation where ABSMSUCAPPING=YES was specified for the z/OS LPAR. ****************************** ** CONCLUSION OF APPENDIX B ** ******************************