I cannot find any documentation on best practices and guidelines to deploy Magento in multiple web front ends (multiple apache versions connecting to a single database).
In practice, I'm experiencing serious issues when it comes to upgrades and session storage (each frontend running redis on master/slave config.).
Are there restrictions that I'm not aware of that prevent this kind of setup? I'd like to have 2 or 3 magento web frontends behind a load balancer and while I can get it to work at first, it breaks after either upgrading magento, or taking the master redis server offline (maybe my redis backup config on env.php is wrong?
It is possible to do this. Requires some DNS and SSL cert setup as well as other tweaks. Happy to help if you would like to know more.