Intermittent HTTP 502 error with Amazon (AWS) load balancher and Apache

Solution 1:

I came across this forum post: AWS Developer Forum

The last entry actually gave me the answer:

Ensure you're not using Apache's event MPM module (default) when behind a ALB/ELB. It dynamically closes connections. Try worker MPM.

I changed my Apache config to use worker MPM and as far as it goes, I did not had any 502 errors.