Issue
Just curious to know if there are a list of steps that I can use as guidelines to debug performance issues to pinpoint what is taking the most time. There are a myriad of tools starting with logging, timing methods, load test tools, timing database queries and so on....
considering that there are so many different things, is there a list of things that are at the top of the list.
if so please let me
Solution
- Check the machine physically has enough RAM. Paging will kill applications.
- Check what proportion of the application's time is spent in garbage collection. A high proportion means you'll benefit from heap or GC tuning.
- Run the app in a profiler and put it through its paces, monitoring CPU usage. Look for those methods where the CPU spends all its time. A good profiler will let you roll up the time spent in third party code where you have no control, allowing you to identify the hot spots in your own code.
- For the top hot spots in your application, work out where the time is being spent. Is it all I/O? Calculations? Multi-thread synchronisation? Object allocation/deallocation? A poor algorithm with n-squared or worse complexity? Something else?
- Deal with the hot spots one at a time, and each time you change something, measure and work out whether you've actually improved anything. Roll back the ineffective changes and work out where the problem has moved to if the change worked.
Answered By - Bill Michell
Answer Checked By - Cary Denson (JavaFixing Admin)
