WebSphere MQ Component

IBM’s WebSphere MQ products enable programs to communicate with one another across a network of unlike components (unlike processors, operating systems, subsystems, and communication protocols), and allow the communication between programs to take place at different times.

This flexibility is possible because the programs use a consistent application programming interface. Applications designed and written using this interface are known as message queuing applications, as they use the messaging and queuing style:

Messaging. Programs communicate by sending each other data in messages rather than calling each other directly.

Queuing. Messages are placed on queues in storage, allowing programs to run independently of each other, on systems with different speeds and at different times, in different locations, and without having a logical connection between the programs.

WebSphere MQ for z/OS provides facilities that collect statistics and accounting information, and record the information to SMF.

The WebSphere MQ Component of CPExpert identifies common performance problems with WebSphere MQ for z/OS. The WebSphere MQ Component of CPExpert analyzes the standard WebSphere MQ for z/OS data, as written to SMF. CPExpert processes statistics data contained in Type 115 records and accounting data contained in SMF Type 116 records. SMF Type 74 (Coupling Facility Activity) records are optionally analyzed to identify performance problems with shared WebSphere MQ queues.

The SMF data must be processed by MXG (from Merrill Consultants, Dallas, TX) or processed by MICS (from Computer Associates), and placed into standard SAS files.

For comprehensive analysis of WebSphere MQ performance problems, the SMF Type 116 accounting records must reflect the "new" accounting data released in WebSphere MQ Version 5.2.

With the initial release of the WebSphere MQ Component, performance problems are analyzed in the following areas:

Queue Manager problems. This analysis identifies problems with basic queue manager parameter specifications, assignment of queues to page sets, assignment of page sets to buffer pools, applications commit activity, and incorrect queue index specifications.

Buffer Pool Manager problems. This analysis examines problems with the use and availability of buffers in each buffer pool, the size specified for specific buffer pools, the I/O activity to page sets on DASD, synchronous and asynchronous write activity (both exceeding thresholds and in-use pages during commit), and the characteristics of messages assigned to buffer pools.

Log Manager problems. This analysis examines problems with backout activity, allocation of active logs, messages written to active logs, messages written to archive logs, and checkpoint activity.

Server problems. This analysis examines problems with DB2 server calls, DB2 server delays, DB2 server deadlocks and ABENDs, and other areas that indicate DB2 performance problems.

Shared queue and shared queue cluster problems. While some of this analysis is done based on SMF Type 115 records, comprehensive analysis is done on SMF Type 74 records. This analysis examines coupling facility structure definitions and usage for WebSphere MQ shared queue structures.

After analyzing the data contained in SMF records, the WebSphere MQ Component produces a narrative report. This report identifies problems or potential problems that restrict the performance of the WebSphere MQ subsystems.

The analysis done by CPExpert’s WebSphere MQ Component can be controlled using guidance variables. Default values are provided for the guidance variables, but the defaults can be changed to suit management objectives or workload priorities.

The WebSphere MQ Component includes an extensive user manual. The WebSphere MQ Component User Manual:

Suggests the likely effect of each finding on the performance of the WebSphere MQ subsystem being evaluated.

Explains why the finding was made.

Suggests alternatives to correct the problem.

Provides specific references in IBM documents where the problem is described.

Initial users of the WebSphere MQ Component are encouraged to provide data for periods of poor WebSphere MQ performance, and free analysis of the data will be done. This will ensure that the WebSphere MQ Component can be enhanced to automatically identify new causes of performance problems.

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Last updated by Don Deese on 05/20/10.