I've seen several questions posted but they either blow passed this specific item or go unanswered.
Basically, I have a load balance set up between two instances of the same wordpress website with nginx
out front. In order to successfully login I have to pin all requests for /wp-admin
or /wp-login.php
to a particular server. It doesn't seem to matter which server, as long all the requests go to the same server.
At first I thought one server was saving session data, but I clustered my PHP sessions only to find it not saving anything. I've checked cookies but nothing server-sensitive appears there (just the WP test cookie which has static value). I continuously monitored the file system to see if maybe a file was being created on one of the backend application servers but to no avail. I've even checked the login form which seems about as basic as they come.
I just literally have no idea why WP would even care which server actually got the POST
request.
I can supply the nginx config if you want but it's pretty straightforward and I don't want to clutter this post.