Speedier Web Services that involve CICS Applications with CICS TS 5.3 – CWXN Elimination

CICS TS 5.3 introduces a capability to eliminate the execution of the CWXN transaction for some web service applications.  As stated in the IBM Redbook IBM CICS Performance Series: Web Services Performance in CICS TS V5.3:

“For applications that use the CICS web support (either as a web application or as a web service), optimizations have been made to remove the CWXN transaction where it is no longer necessary. If an inbound request is received by CICS, the user transaction will be directly attached without an intermediate CWXN transaction, if the following conditions are met:

(see conditions below)

This removal of the CWXN transaction results in an improvement in the CPU consumed per web request.”

The Redbook goes on to quote CPU performance savings of 8-10% when specifically running a configuration that allows for CWXN elimination (HTTP, not HTTPS) and also documents a DASD savings due to the generation of less SMF records of type 110.  (Additional savings can be had for anyone using SSL encryption by taking advantage of new AT-TLS capability; see the Redbook for further details.)

As of  version 6.78, HostBridge has been enhanced to take advantage of this performance enhancement.

Here are the criteria for determining whether or not HostBridge requests can be run without the CWXN transaction:

  • You must be running CICS TS 5.3 or later.
  • You must be running HostBridge 6.78 or later.
  • You must define a set of URIMAPS and a new TCPIPSERVICE definition to allow CICS to realize that the incoming HostBridge request is eligible for CWXN elimination.
  • You must be issuing HostBridge requests to CICS using the HTTP protocol.  Any requests using the HTTPS protocol or other protocols than HTTP will not be considered for CWXN elimination.
  • You must indicate in your URIMAP definitions that there is no analyzer program to execute by setting the ANALYZER parameter to NO.
  • You may not issue HostBridge requests where HostBridge is defined as a trusted host.

In our testing, we have determined that the performance savings for HostBridge are equivalent to the results that IBM quotes in the previously mentioned Redbook.

Please contact HostBridge Technology if you have any questions about the ability to eliminate the CWXN transaction from HostBridge web service applications.

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