Graph of free memory on a node with a leaking piece of software.
This is a scary problem when you’re recovering from an outage of your database machines. If you’re running a Galera cluster and they all go offline, you’ll need to do a bit of work to restart the cluster and make it safe.
This is another one of those things that is pretty straightforward, but requires culminating information from a different sources in order to get things up and running. The goal here is to get Zabbix to monitor our MariaDB (MariaDB is a drop in replacement for MySQL, I’ll refer to either as MariaDB here) server’s status. There’s a built in template, but a few other files and settings need setup before you can get the juicy data flowing.
This is a problem that showed itself when upgrading our Proxmox 3.2 Nodes up to Proxmox 4. About halfway through the upgrade, our network adapters suddenly stopped being able to communicate with any local addresses, but could still ping outside addresses.
Setting up OpenVZ containers to be able to use a FUSE filesystem is pretty simple, but it takes a bit to figure out exactly which steps you need to follow. There are a myriad of tutorials online (and here’s yet another), but this one focuses specifically on Gluster, a distributed network file system.