The Performance Analyzer (PAL)
Analyzing application performance with the PAL tool
The Performance Analyzer (PAL) provides a view to all the performance statistics that Pega Platform™ captures. You can use PAL to understand the system resources consumed by processing a single requestor session.
PAL is available on the Performance landing page (Dev Studio > System > Performance) or from the Performance tool in the toolbar.
Measure performance
The first step to measuring your application performance is to take measurements. You start by clicking Reset Data to clear any data in the tool. Since the system is continuously monitoring performance, you are eliminating any previously recorded entries from your results by resetting data.
You have two options for adding a reading: Add Reading and Add Reading with Clipboard Size. The only difference between the two readings is the addition of the clipboard size, which takes extra time to calculate.
When adding a reading, the best practice is to define points that identify what occurred during that reading. For example, use one reading per flow action or screen render, depending on what process you are measuring.
Click Save Data to download the results to an Excel file.
Analyze performance data
The INIT row displays the totals from the first time the Performance tool made a reading. Each subsequent reading is labeled as a DELTA — this indicates the change from a previous reading. The FULL reading is the total sum of all the statistics from the last time the data was reset.
In the following two images, which represent a single reading, you can see the top delta has a reading of 1.61 for RA Elapsed. All values are in seconds. RA Elapsed represents the time spent in rule assembly. These results can skew performance readings as rule assembly, also known as first use assembly (FUA), is expensive but only occurs once. This is evidenced by the following results. The total elapsed time was 2.82 seconds, with 1.61 seconds of that time spent in rule assembly. Without the additional 1.61 seconds, the total time would be less than half the measured number. FUA also affects the other readings such as the total rules executed, the reads from the database, and various I/O counts.
To obtain results unaffected by FUA, run through the process once to ensure all rules have been assembled before taking any measurements. That was not done in the above example in order to demonstrate the impact this has on performance readings.
Clicking INIT, DELTA, or FULL displays more details about the reading. Many different results are available to you for analyzing the performance.
Results have no magic number. A result of 10 minutes may be acceptable in one situation, whereas a result over 100 milliseconds is considered too slow in another. You must work with the lead system architect and the business architect to determine an acceptable result for each step of the process.