IBM Data Virtualization Manager for z/OS

Performance testing via the Command Line Program (Data Virtualization Manager for z/OS)

By Jonathan Sloan posted Tue July 14, 2020 11:54 AM


Identifying the root cause of a performance issue can be a thorny problem. Pinpointing a problem accurately takes lots of patience and requires measurement at every stage in a process. When it comes to data access and movement there are many factors to consider. Does the system have available resources? Is there a networking bottleneck? Is the requesting application ready and able to consume all the data?  Identifying performance bottlenecks used to be the same with Data Virtualization Manager for z/OS (DVMz), however not anymore.

As there was no other easy alternative, performance testing was accomplished through the Data Studio Eclipse add-in. Truthfully, this is just an inefficient approach. There were many issues that could interfere with actual performance measurement. In addition to Java heap size problems with large query result sets, often the Eclipse add in would reach a data capacity or number of row capacity limit.  This led to lots of false diagnoses.

Recently, the Data Virtualization Manager for z/OS development team released a new utility that can help determine if a performance bottleneck is associated with server performance or perhaps a downstream system.  The development team is making a utility available that allows you to run a query on a client environment and determine if performance associated with a query is due to the something other than the Data Virtualization Manager for z/OS server.

This new utility, the Command Line Program (CLP), is primarily used for evaluating performance for specific queries. It accepts a number of parameters including an SQL statement. The output of the utility is the time it takes for the server to produce a result set and the time it takes to move the data.  The resulting output can help you identify where in the execution process a bottleneck might occur.

Here is the command line program in action

Command Line Program in Action

 Some highlights of the CLP
- no limits on number of rows returned
- reports back the execution time for data movement
- was developed to help isolate performance issues from other tools, such as DataStage, Informatica, etc.
- It can flexibly output results
- command line driven

With the new CLP application, you can more quickly eliminate server performance as an underlying issue, identify the root cause and get your applications up and running faster. You can contact the support team for instructions on how to get access to and use this new utility.