title: Is there any limitation on EC2 machine or network?
body: <p>I have 2 instances on Amazon EC2. The one is a <code>t2.micro</code> machine as web cache server, the other is a performance test tool.</p>
  
  <p>When I started a test, TPS (transactions per second) was about 3000. But a few minutes later TPS has been decreased to 300.</p>
  
  <p>At first I thought that the CPU credit balance was exhausted, but it was enough to process requests. During a test, the max outgoing traffic of web cache was 500Mbit/s, usage of CPU was 60% and free memory was more than enough.</p>
  
  <p>I couldn't find any cause of TPS decrease. Is there any limitation on EC2 machine or network?</p>