Thursday, December 12, 2013

Recording ADF BC View Object Instance Activation Time

Probably you already now - if there are too many Passivation/Activation events happening in the system, this may slow down your ADF application significantly. There are ways how to minimize number of Passivation/Activation occurrences by tuning Application Module settings. This post is about how to track actual time that takes to activate View Object instances - SQL execution and data fetch times during activation.

We need to use several overridden methods from ADF BC API, to track each View Object instance activation time. We are interested in View Object instance activation time, as this is where actual SQL execution and data fetch happens during activation - most of the time during activation is consumed here. Activation happens in following order:

1. Application Module instance is activated
2. View Object instance executes SQL statement
3. View Object instance fetches records from DB
4. Next View Object instance executes SQL statement
5. Next View Object instance fetches records from DB

As you can see, Application Module finishes activation before View Object instances are starting activation. This is the reason, we need to override several methods from ADF BC, to properly track activation time for each View Object.

Sample application - is using similar concepts as implemented in our ADF performance audit tool - Major Release for Red Samurai Performance Audit Tool v 2.0. Generic Application Module Implementation class overrides activateState method, we are using it to set activation event identifier, remember - Application Module is activated before View Objects. We are able to group later all View Objects activated during the same activation event by this identifier - stored temporary in ADF BC memory scope of user data:

Activation start time for each View Object instance is recorded in prepareForActivation method. End time is logged in activateCurrentRow method - this method is invoked after SQL query execution and data fetch, it makes it perfect place to log end time per individual View Object instance:

Application Module Pooling for sample application is disabled - this allows to test how activation time is logged:

This sample application UI - Jobs and Departments View Objects are exposed, both of them should participate in activation events:

Here we can see the log - activation events for Jobs and Departments are started right before Application Module activation ends. Jobs View Object activation ends after Jobs SQL query was executed and data was fetched, activation for this View Object is completed in 16 milliseconds:

Departments View Object is activated next - SQL query is executed, along with data fetching in 47 seconds. Keep in mind - last View Object activation time always will be the longest - as all View Objects instances are prepared for activation before the first View Object instance was activated. Activation process is sequential, each View Object instance one by one. Last View Object instance activation time will show total activation time for all View Objects:

No comments: