The InstanceDestruction event is fired whenever the Application Runtime Environment destroys an instance of a script.

The InstanceDestruction event is provided for developers to execute logic which is needed immediately before an instance is unloaded. Because scripts can end in any number of locations due to EndScript usage, Forward usage, application unloading, and by unexpected errors causing script crashes, the InstanceDestruction script is an ideal way to ensure that any resources that need to be cleaned deterministically occur. A good analogy to help understand InstanceDestruction is the try/catch/finally pattern, where scripts are the code in the try block, application crashes occur in the catch block, and the finally block corresponds to the code in the InstanceDestruction-triggered script.

The InstanceDestruction event provides the ErrorCode and ErrorText event parameters to indicate under what circumstances did the script instance unload.

Implementing the InstanceDestruction event is completely optional.

InstanceDestruction occurs whenever a script is ended with EndScript, Forward, abnormal exit due to unhandled exception or script error, or if the application server is unloading the application. Refer to ErrorCode regarding more information on specific reasons for script instance termination.

The InstanceDestruction event handler has up to 30 seconds to finish, by default. This amount is configurable on an application server-wide basis.

If an application is being unloaded due to the application server service stopping or if the application is being uninstalled, the script has excecution stopped immediately and then the InstanceDestruction event handler is executed.