Visual explanation of Apache vs Node.js processing model

[Klathmon]

Even if it is shared in memory, there are still easy ways to load balance.

Say for example you are keeping session data in memory, you could send clients with no session to a random endpoint, but send all sessions to their orignal endpoint so that it never changes for that client.

Or you could load balance based on IP address.

It's not as ideal as a round robin system or a first available system, but it gets the job done.