Power Debugging Notes

[Scott Hickey]

What a fun metting! It great seeing so many people there and at the Old Chicago afterwards.

Below is a cut and paste of the notes had for my presentation. Please feel free to respond to the list or contact me directly if you have any questions,

Scott Hickey

Introduction

• The challenge
• long running processes
• complex object graphs
• need more output than is easily readable in the debugger
• need more power than the expressions window
• need more power than the custom formatter
• need to do exploratory coding with objects they way we’d use SQL on database

The Tools

• Groovy Console
• interactively execute groovy code
• code completion
• color-syntax highlighting
• create complex objects in Java, inject those objects into the Groovy Console context, and launch the Groovy Console
• embed the Groovy Console into a web application and launch a web console
• objects stay in the context, but objects created in the console don’t
• use inspect last to view last result
• Clojure REPL
• run from inside of Eclipse or Emacs
• Eclipse CounterClockwise plugin is getting better every month
• “Load File in REPL” - everything created is live
• easily run and save code a command at a time
• easily create and reference results of commands



Strategies for Development and Production Support

• Use snapshots of source data(base)
• xml or Java serialized files
• use a test harness to launch your process
• use a test harness to create your application context
• make the result available to the console or repl
• interactively use the application components to further understand how your app is behaving
• Use snapshots for interesting objects
• use AOP to serialize results a specific points in the process
• could be triggered automatically with exception handling advice
• trigger it on/off with logging setting
• use a test harness to run and write the result objects to disk
• write a Groovy or Clojure script to deserialize and pull the objects into the GroovyConsole context or the Clojure REPL
• Embed in TestHarness
• build out a custom GUI specific for your application
• build a library of useful methods for running processes or displaying/inspecting complex objects
• Embed in an Admin Console on a Running Application
• very useful interacting with system components