title: How to ease high SoftIRQ (si) CPU
body: <p>Using LVS or Nginx for load balancing on CentOS under high network volume.
  Network traffic is mainly small packets with a lot of connection and relatively low bandwidth.</p>
  
  <p>The only thing that seems to become the bottleneck is high SoftIRQ which come as no surprise on event based IO.</p>
  
  <p>Machine has 4 NICs but only one is enabled.</p>
  
  <p>Linux kernel experts should know whether connecting more NICs would ease some of the software interrupts on Multiprocessor.</p>