CA Datacom CICS performance WAIT EXTERNAL

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Article ID: 131683

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Products

CA Datacom CA DATACOM - AD CA Ideal CA CIS CA Common Services for z/OS CA 90s Services CA Database Management Solutions for DB2 for z/OS CA Common Product Services Component CA Common Services CA Datacom/AD CA ecoMeter Server Component FOC CA Easytrieve Report Generator for Common Services CA Infocai Maintenance CA IPC Unicenter CA-JCLCheck Common Component CA Mainframe VM Product Manager CA Chorus Software Manager CA On Demand Portal CA Service Desk Manager - Unified Self Service CA PAM Client for Linux for zSeries CA Mainframe Connector for Linux on System z CA Graphical Management Interface CA Web Administrator for Top Secret CA CA- Xpertware

Issue/Introduction



A  CA Datacom CICS transaction is having performance problems.
A CICS trace shows  lots of WAIT EXTERNAL commands coming from program DCCTRPR.
Is this a problem?
What can be done to improve CA Datacom CICS Services performance?

Environment

z/OS and z/VSE operating systems

Resolution

A WAIT EXTERNAL in CICS is normal for a CA Datacom CICS program.
It means the program has sent a request to the Datacom MUF and is waiting for a response.
 
There is a performance enhancement which replaces CICS WAIT EXTERNAL with MVS WAIT/POST API for programs running under OPEN TCBs, it was introduced in PTF RO92668 for  DBC15.0 or RO88191 for DBC 14.0. 

It is best to also apply the latest PTF which delivers performance enhancements and all their pre-reqs:
RO97469 for DBC 15.1
RO97508 for DBC 15.0
RO97640 for DBC 14.0

For best performance code DBCVTPR with the following options, then assemble and link DBCVTPR and recycle CICS : 

DBCVTPR SKPSYNC=YES,CICSTRA=NO,FLOWTRA=NO,INTLTRA=NO,OPENAPI=YES,PGMNAME=TASK 

The other thing to check is if the application is defined as threadsafe, the CICS program definition should have option CONCURRENCY(THREADSAFE). 

For CA Ideal, it is threadsafe only if using load modules. If using VLS object it cannot run threadsafe. 
The only programs that need to be defined with CONCURRENCY(THREADSAFE) are the VPE modules that interface with CICS, the VPEHJEnn and VPEHJNnn programs. 

Additional Information

See KB000019090 for more information on Threadsafe. 
Se DocOps section Specifying Generation Options (DBCVTPR)