Dynamic Diagnostics Auto Instrumentation (DDAI)

Auto-Instrumentation feature auto-detects instrumentation profiles of relevant methods. It works on below algorithm:

  1. Start an instrumentation session for some duration.
  2. Find all executing methods in active threads at regular interval.
  3. Instrument top executing methods.
  4. Monitor methods after instrumentation for some time.
  5. If methods are cluttering the flow path without significant execution time, remove instrumentation for those methods.
  6. At the end of instrumentation session, create instrumentation profile as an output with relevant methods.

This whole process is time consuming, as it has to take in-memory thread dump at regular interval and find out all methods in active threads. During this session, CPU consumption is also high.

To tackle this problem, Dynamic Diagnostics auto instrumentation is implemented. It is a light weight solution of finding problems in business transactions. Dynamic Diagnostics instrumentation is triggered only on specific Business transaction, and stack dump is considered only for those threads, which are executing that transaction.

DDAI is supported from following screens of DDR:

  1. FlowPath Report

An icon is provided in Filter Criteria at Right side to Start Instrumentation.

Select any one row and click on icon to Start Instrumentation. This feature works when the test is running otherwise a message prompts “Could not Start Instrumentation as Test is not Running”.

Case 1: When Test is not running

Case 2: When Test is running

On clicking the icon, a pop-up is displayed which shows following information: BT, Tier, Server, Instance, duration, etc.

Click the Start button to start instrumentation.

User can see the running processes in “ND-CONFIG GUI” by clicking on “Instrumentation finder” icon on left side bar. User can stop the process and click on refresh icon to see time interval for how much time it is running.

Similar approach is used from Method Calling Tree and BT Trend.

  1. Method Call Details

To go to Method Calling Tree report, click on Methods column in Flowpath Report.

Click  icon to Start Instrumentation.

  1. BT Trend

In this report, Start Instrumentation option will appear only at Instance level not Tier Level.

To go to Instance level, first select the “Show Tier Info” option.

Go to Health tab and select Instance:

After Selecting Instance, following screen appears:

To view BT Trend report, click on Total Count or Transaction Score Board or Normal / Slow / Very Slow / Error.