I’ve been building a larger version of my Banana Pi cluster. It was originally built with just four nodes, but I’ve extended it to 8. There are
now four database servers running MySQL which are synchronized using master/slave replication. There are four web servers with Nginx and uWSGI
I plan on adding another four Banana Pis as web servers. Pages are cached on the web servers, so most pages are served without needing to access
the database. There isn’t much load on the database servers, so it shouldn’t be a problem to have more web servers than database servers.
The web servers are synchronized using rsync. I’ve set up ssh keys so that I can use rsync over ssh without having to enter passwords. The web
root directory and the Pyplate directory are synchronized from a master web server to the workers in the web server cluster.
I’ve moved pyplate.com to the new cluster, and I’m working on new sites that will also be hosted on the cluster.
I’m using Ganglia to monitor both clusters. It’s almost set up the way I want, except the master web server doesn’t appear in the Ganglia UI.
I’ll check the settings in gmond.conf on the node I’m having problems with.