title: How to increase network bandwidth of AWS EC2 instance?
body: <p>We hosted a site in AWS EC2 of type c4.8xlarge. It is a fairly large system with lot of memory and compute resources. Thousands of users tried to access the system during a 2 hour timeframe this weekend. While it did not crash, it slowed down quite a bit and failed to perform at the expected level. Analyzing the stats showed that limited network bandwidth is the main cause of the slowdown. The CPU usage stayed below 6%, but NetworkIn and NetworkOut seem to have peaked at 60MB and 200MB respectively during that timeframe. While I'm not an networking expect, some reading online seemed to indicate that all the traffic going through one NIC could be the main cause of limited network bandwidth. Is this true? Would hosting the site on a different type of EC2 instance help increase the network bandwidth? Here is how the networkIn and networkOut metrics looked like under heavy load.</p>
  
  <p><img src="https://i.stack.imgur.com/KmLin.png" alt="networkIn and networkOut metrics chart"></p>