How to deploy in a a load balancing environment?

[poorejc]

Moving question over from incubator-flagon-useralejs:

We have a proxy server that redirects user requests to different servers for load balancing. On the proxy side we have our UI application. Some analytics do need to track information about the host. That being said what is the advice wrt:

Capturing every user interaction with the application would eventually end up creating large volume of data relatively quickly. Is there a way to purge data that is “x” days old or some retention/deletion policy of some sort?
Is there a need to have a cluster of ELK or is one sufficient?

[brucearctor]

As a question would this be better for https://docs.github.com/en/discussions or on-list? Is this an issue [ to me that means a potential to-do item ]. I don't understand how to mark this 'issue' complete. But, we haven't yet established community practices around this.