The CICS Component of CPExpert

 
The CICS Component evaluates the performance of individual CICS regions, identifies potential constraints to improved performance, and suggests ways to eliminate the constraints. The CICS Component automatically applies most of the CICS analysis techniques documented in IBM's CICS Performance Guides.

The CICS Component analyzes CICS interval statistics for CICS Version 3, CICS Version 4, CICS/Transaction Server for OS/390 (Version 1.1, Version 1.2, and Version 1.3), and CICS/Transaction Server for z/OS (Version 2.1, Version 2.2, Version 2.3, Verson 3.1, and Version 3.2).

These interval statistics are automatically recorded by CICS and normally are placed in SMF Type 110.  Only SMF Type 110 (Subtype 2, and optionally Subtype 3, Subtype 4, and Subtype 5) interval statistics records are processed by the CICS Component.  Additionally, the SMF Type 88 (System Logger) records will be processed if you wish the CICS Component to analyze problems with CICS regions using system logger.  MXG must be used to process the CICS interval statistics and place the results into your performance data base.

The CICS Component analyzes the CICS statistics in the following major areas:

Virtual and real storage (task controls: MXT, AMXT, TCLASS).

VSAM and File Control (NSR files and LSR pool specifications).

Database management (CICS specifications for DL/I, IMS, DB2).

Journaling (system journal and user journal specifications).

Network and VTAM (RAPOOL, RAMAX).

CICS Facilities (temporary storage, transient data, dynamic backout).

ISC/IRC performance (MRO, LU6.1, LU6.2 modegroups).

System logger problems (from the view of CICS).

Shared temporary storage.

Shared data tables.

Coupling Facility Data Tables (CFDT).

CICS-DB2 Interface.

Open TCB pools.

TCP/IP internet connectivity (IPIC).

You can alter the analysis performed by the CICS Component by using guidance variables. Default values are provided for the guidance variables, but you can change the defaults to suit your management objectives or workload priorities.

After it analyzes the CICS statistics, the CICS Component reports problems or potential problems which restrict the performance of the CICS region. Sample findings by the CICS Component are: 
The MXT value may need adjusting.
The number of GETMAINs per task may be too high.
VTAM reached the maximum RAPOOL value too often.
The number of strings may be too low for VSAM NSR file.
The number of strings or buffers is too low for VSAM LSR pool.
The "look-aside" read hit ratio was low for VSAM LSR pool.
The LSR buffer sizes may be incorrectly specified.
The size of the temporary storage data set may be too small.
The number of Temporary Storage strings or buffers may be too low.
The number of DL/I Threads may be too low.
The DLTHRED specification may be too high.
The DMBPL specification may be too low.
The ENQPL specification may be too low.
The number of Transient Data strings or buffers may be too low.
The CICS journal buffer size is too small.
The CICS Dynamic Transaction Backout buffer size may be too small.
The ICV value may be inappropriate.
The MROBTCH value may be too large.
An APPC modegroup may have insufficient sessions defined.
Conflicting usage may exist between APPC modegroups.
Connection problems caused generic ALLOCATE requests to fail.
Balance between contention winners and losers may be inappropriate.
Insufficient sessions were defined for tasks which were using NOQUEUE option.
CICS waited for logger "structure full" condition.
Log stream structure offloads occurred: 90% full.
High data set activity for CICS-maintained shared data table.
DASD staging data set high threshold was reached.
Log stream caused structure to reach high threshold.
Peak open (H8 mode) TCBs in use was approaching MAXHPTCBS
There was excessive MVS storage constraint for JVM

Sample output from the CICS Component.

The CICS Component includes an extensive user manual. The CICS Component User Manual (1) indicates the likely effect of each finding on performance of the CICS region, (2) explains why the finding was made, (3) suggests alternatives to correct the problem, and (4) provides specific references in IBM documents where the problem is described.

Sample "rule" description from the CICS Component User Manual.

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Last updated by Don Deese on 10/26/08.