Load Balancer Briefly Explained

A load balancer is a hardware or software unit that intercepts and distributes network traffic to a group of servers. It allows the application to scale up or down by being aware of which servers are under- or overutilized, and routes user traffic accordingly.

For instance, if a server were to drop out, the load balancer would be responsible for redirecting traffic to servers that are capable of serving them.

The importance of load balancers becomes particularly important during traffic spikes.

Traffic distribution

The distribution of traffic happens with the use of algorithms, with each having their own pros and cons. Common examples of algorithms are:

• Distributing traffic load sequentially on every server (Round Robin),
• Using the IP address of the client (IP Hash), or
• Randomizing the distribution (Power of Two Choices).