Performance Test Result Analysis is the most important and technical part of performance testing rather than scripting and execution. A performance tester requires his actual expertise to carry out the test result analysis phase and conclude the testing. This phase is also important because a performance tester has a list of dependent tasks to perform in this phase like to analyze the graphs, check the metrics, find-out the bottlenecks, compare the result with defined NFRs and at last, conclude the test result. A small mistake in result analysis may cause a big disaster in the live environment. That mistake could be due to lack of experience. Hence a senior performance tester or manager has to review the performance test results before concluding and out for the client.
In this phase, a performance tester determines the bottlenecks and remediation options at the appropriate level – business, middleware, application, infrastructure, network etc. and highlight them in the test report.
Now, the next question comes how to start performance test result analysis so that an accurate test report can be concluded?
This topic is divided into 3 levels to make it simple and easy to understand. The levels are:
- Basic Level describes the common graphs of performance testing.
- Intermediate Level shows how to analyse client, server and network side graphs.
- Advance Level describes the different approaches of analysis of performance test result
Before starting the Performance Test Result Analysis there are some Important Points which has to be kept in the mind:
- You should eliminate “Think Time” from graph/stats.
- You should eliminate “Pacing” (if tool considered) from graph/stats.
- No tool-specific error should occur like the failure of load generator, memory issue etc.
- No network related issue should occur during the test like network failure, LGs become disconnected from network etc.
- The test should run completely for the specified test duration.
- The result should be collated successfully at the end of the test.
- CPU and Memory utilization percentage should be noted down for pre-test (at least 1 hour), post-test (at least 1 hour) and during the test.
- Use proper granularity, so that peaks/lows can be correctly identified.
- Optional but helpful – the tool should have graph merging option available. The analysis of graphs in the separate windows makes the analysis work hectic and time-consuming. To make the task easy tool should have a graph merging option. Using this option you can merge different graphs and do the investigation to find the root cause of bottlenecks.
- Do not try to extrapolate the result on the basis of incomplete statistics.
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