Before you invest in load balancing

The gap between knowing this and actually doing it is where most teams lose ground. Before you spend anything on load balancing, it is worth confirming a few things are already true.

Cloud work rewards teams who automate early and punishes teams who click through consoles. Budget a little time for it every quarter and it never becomes a project of its own.

Prerequisites

• You can describe the outcome you want in one sentence
• Someone owns it after the work is done
• Health checks decide whether load balancing helps or hurts
• You have a way to tell whether it worked

Common failure modes

Sticky sessions quietly limit how far you can scale. In practice this is a scheduling problem more than a technical one. It rarely shows up as a line item, which is exactly why it slips.

Test what happens when one instance is slow rather than dead. In practice this is a scheduling problem more than a technical one. Doing this properly once is usually cheaper than doing it approximately three times.

In practice

The bill is a design document: it tells you exactly what your architecture actually does. Three things worth confirming about load balancing before you move on:

• Someone can say what the current setup is without going to look
• Test what happens when one instance is slow rather than dead — and you know whether that is true here
• There is a way to tell whether the last change to this helped

If any of that sounds like a description of your current setup, it is fixable.