I've been having this problem with my production setup, and we are currently down because I can't seem to rectify it. Everything points to a cache issue, for which we use redis. I've tried restarting our redis server, as well as our MariaDB install and even nginx on both web servers. So far, I have yet to make the site usable. Can anyone at least point me in the right direction of how to start debugging? The site was working just fine and was actually running pretty quickly up until a few hours ago, when this error suddenly appeared and took down the site. This is with a load-balanced server setup including two web servers with nginx, a PHP-FPM server, a MariaDB server, a redis server, and an NFS file server which contains the codebase. All of them run on Ubuntu 14.04. Any help is greatly appreciated. ---- Justin Folvarcik