Network engineers should know by now that hardware load balancers are not a long term career option. In addition to virtual appliances and Open vSwitch (included in VMware NSX) replacing them, there are a number of application load balancers like HAProxy that make them obsolete. Here is Twilio taking about their implementation:
This is the state we got into with our HAProxy settings in the olden days of Twilio. All of our HAProxy configs were copies of each other, with some of the timeout values changed. In our quest for five nines of reliability, we tightened up our HAProxy configs and made sure they were appropriate for the service and traffic being carried. Let’s walk through a sample configuration.
I think it’s important to realise that many newer applications are implementing their own application load balancing solutions and no longer require network load balancing. A few years ago, NLB was the primary solution for load balancing but tomorrow it will be different. DevOps and automated deployment is much harder (if not quite impossible) when using a load balancer / application delivery controller.
It makes much more sense to build something in Linux today that is free and open. Sadly, network load balancing as we know it will stop being useful in the years ahead.
Twilio – Getting the most out of HAProxy.
Hat tip to High Scalability