Performance Testing

This is a rough outline of my post, will be improved..

Goal: Performance test a Java application - Rest API, load balanced on linux nodes.

1. 1. Generate requests i.e. the load for performance test through JMeter or Silk (simulating 1000s of client requests)
2. 2. Take one or 2 server nodes as sample and extrapolate.
3. 3. Monitoring tools can be  - Jconsole (comes with JDK) and vmstat - available in Linux.
4. 4. Metrics to be measured are - 
1. CPU usage
2. Number of threads
3. Memory saw tooth
5. Example of unnecessary high CPU usage in code 

while(true)

{

 if(some-externally-flag){

}

}

This will cause an extraordinary amount of churn.