In the February/March issue of z/Journal, we examined the Web Services support provided in CICS Transaction Server V3.1. In this issue, we provide guidance on the diagnostic capabilities and problem determination techniques appropriate to this new programming paradigm within CICS.
CICS Transaction Server V3.1 introduces a range of enhancements that improve access to CICS, enable the development and transformation of CICS applications, and also further enhance the systems management capability as provided by CICSPlex.
An important cornerstone of the enhanced access to CICS is provided by CICS Transaction Server V3.1’s support for Web Services. Web Service support is an evolution of the ideas and functionality initially provided by the “SOAP for CICS” optional feature. It provides the ability to integrate both new and existing CICS application programs within a Service-Oriented Architecture (SOA). This enables CICS applications to be exposed as Web Services, extending their use and furthering their business value.
There are two parts to this support, the CICS Web Services Assistant (CWA) and the run-time support. Our previous article examined this new capability. Both the CWA, which runs as batch jobs, and the CICS run-time produce useful diagnostic information that should be examined if you encounter problems setting up Web Services in CICS.
Diagnostics: From the CICS Run-Time
The traditional First Failure Data Capture (FFDC) mechanisms of system dumps, CICS standard and exception trace entries, and diagnostic and error messages are provided by the various components of CICS that work together to support Web Services.
The Pipeline domain (PI domain) provides diagnostic features for problem determination. Abend codes with the three-letter prefix “API” are used to identify transaction abends associated with problems in this area. Likewise, messages prefixed by “DFHPI” are provided to identify various informational and diagnostic situations. By default, these messages are directed to the MVS console or to the APIO transient data queue.
Formatting a CICS Transaction Server V3.1 system dump using the “PI” VERBEXIT under IPCS will display control blocks and summaries of the Pipeline domain environment at the time the dump was taken. The formatted dump summary shows the current number of PIPELINEs installed in CICS, and details attributes such as their name, type (i.e., service requestor or provider), pickup shelf, WSBind file directory, use count, etc. For each WEBSERVICE, the formatter describes its name, current and total use counts, and its status at the time of the dump (e.g., was it in service or not).
Likewise, a CICS system dump may be formatted using the “TR” VERBEXIT to display the system trace activity prior to the dump request. PI domain trace points are denoted by “PI” in the third (domain identifier) column of abbreviated trace output.
Pipeline domain modules adhere to the standard CICS naming convention prefix of DFH plus domain identifier; i.e., “DFHPI”. The Pipeline domain module names, functions, and the domain gates and responses are documented in the CICS Diagnosis Reference manual. There are no CICS Global User Exit points (GLUEs) within the Pipeline domain.