Tracking IMS application response time within a Shared Queues environment
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The IMS shared queues environment allows customers to distribute their application workload over a set of connected IMS systems. Whether a front-end / back-end or a load balanced environment, messages are queued to one system and may be processed on another. This can lead to questions such as:
The Response Time Analyzer (RTA) component of OMEGAMON XE for IMS on zOS can help answer these questions. RTA has long tracked application response time within an IMS system, but as of v420, it can track application response time over an IMSplex.
RTA acquires it's information from the IMS log. As buffers are written out to the OLDS, a copy of the buffer is made and transferred to the OMEGAMON address space. The RTA data analyzer reads each log record and calculates application response time metrics. Each instance of RTA monitoring an IMS within the plex communicates via XCF with the other RTA instances. In this way, an message originating on IMS1 and processed on IMS2 can be tracked by RTA.
RTA analyzes and breaks down response time into the following components: Input and/or Program Input, Processing, and Output times. In addition, RTA creates two additional components R0 and R1. R0 represents the time the application spent on the queue to the time it completes processing (Input + Processing). R1 time is the summation of R0 and Output times (Input + Processing + Output).
The following chart shows, for a full-function transaction, the log records processed by RTA monitoring the Front-End (FE) originating and Back-End (BE) processing systems.
Each RTA monitoring instance will communicate, in real-time, with it's partner RTA on the originating and/or processing system and share response time information. In this fashion, each RTA will calculate the time spent on the shared queue (local + global) on both the input and output sides to present a unified view of response time over the IMSplex.
This has been a high-level overview of how RTA tracks IMS application response time over an IMSplex in real-time. The next blog will demonstrate the RTA real-time displays and how to enable and use OMEGMON XE for IMS Response Time Analysis.