Managing parameters to improve IMS performance

You can use IMS Configuration Manager with IMS Performance Analyzer to improve IMS performance.

IBM® IMS Performance Analyzer for z/OS® (program number 5655-R03) is an ISPF application to assist with IMS system performance monitoring and tuning, resource utilization, transaction transit analysis, capacity planning, and management reporting.

IMS Performance Analyzer provides a comprehensive set of reports that help you identify performance problems. Some of the reports can highlight problems that can be solved by modifying IMS setup and performance parameters that are managed by IMS Configuration Manager. For example:

You can use IMS Configuration Manager to search across a system, group of systems, or a PROCLIB to quickly find and easily change parameters that can impact IMS system performance. For example, you can search for all VSAM BUFFER parameters.

Figure 1. Searching for VSAM BUFFER parameters in IMS Configuration Manager
   File  Help 
 ───────────────────────────────────────────────────────────────────────────────
 VIEW     USER.NEW.V13.PROCLIB                                       Row 1 of 62
 Command ===>                                                  Scroll ===> PAGE

 Search . . . VSAM BUFFER                                        

    Member 
 /             Prompt   Lib   Size  Created     ----- Changed -----  ID     
   DFSDFCOM              1     17  2013/04/10  2013/08/20 09:47:23  USER
     DBD=...           Assign the indicated subpool to a DBD data
     POOLID=...        VSAM shared resource pool subpool definiti
     VSAMXXX=...       Dynamic subpool definitions for VSAM secti
     VSRBF=...         VSAM subpool definitions for one subpool
⋮
 --------------------------------------------------------------------------- 
   DFSVSMIT              1     33  2013/01/10  2013/06/11 15:21:24  USER
     BGWRT=...         Activate background write
     DBD=...           Assign DBD data set to a shared resource p
     DEDB=...          Fastpath buffer pool definition
     DEDBMAS=...       Fast path buffer pool for multi-area struc
     INSERT=...        Buffer handler insert mode for new KSDS re
     RESVPOOL=...      Prevent IMS use of listed VSAM LSR pools
     VSAMFIX=...       Page fix buffer subpools and control block
     POOLID=POOL,FIXDATA=YES,FIXINDEX=NO,FIXBLOCK=NO,STRINGNM=1   
     VSRBF=32768,32767,I,HSR,HS3                                  
     VSRBF=32768,32767,D,HSR,HS3                                  
     VSRBF=2048,20     VSAM subpool definition
     VSRBF=4096,40     VSAM subpool definition
     VSRBF=2048,10,I   VSAM subpool definition
     VSRBF=2048,10,D   VSAM subpool definition
     VSRBF=4096,20     VSAM subpool definition
     VSRBF=4096,10,HS40,HSR                                       
     VSRBF=8192,10,HS50,HSRE                                      
     VSRBF=12288,4,HS12                                           
     VSRBF=16384,4,HS20,HSO                                       
     VSRBF=20480,4,HSOP,HS8                                       
     VSRBF=24576,4,HSOPTIONAL,HS8                                 
     VSRBF=28672,3,HS9,HSREQUIRED                                 
     VSRBF=32768,3,HSREQ,HS9                                      
     CFNAMES,CFVSAM=(YCCCCCCCCCCCCCCC)

You can then use IMS Performance Analyzer to provide an insight into the effect on system performance of particular parameter settings.