If you’re not running Amazon Linux with the built in network interface management tools, adding multiple ENIs on the same subnet can be a confusing experience. We use this sometimes to run multiple elastic IPs on separate network interfaces so we can bind to them separately. We worked through this with Amazon support recently and […]
We have a client that keeps encountering a tremendous load on their WordPress Mysql database despite a trivial amount of normal traffic on their blog and lots of tuning that eliminated most normal database access. We tracked this down to the AdRotate plugin, and specifically the tracking callbacks to the admin-ajax interface in WordPress. Each […]
If you use EC2 instances for tasks that only need to be performed during work hours, it can be challenging and annoying to manually start up and shutdown instances when you need them. There are services that can handle this for you (Skeddly, Ylastic, etc) but they cost money and are overkill for small companies […]
We use OpenVPN and OSSEC together regularly. Unfortunately, OSSEC doesn’t do any useful interpretation of OpenVPN events out of the box. Instead, you’ll wade through a stream of event id 1002s in your email to see what’s going on with OpenVPN. We recently sat down and drafted a custom decoder and a few custom rules […]
Journald – a contentious subject in the Linux community. On one side, proponents tout advanced features and security. On the other, die-hard *nix users decry yet another move away from the simplicity of text files and more towards the Windows way of obfuscated binary file based systems. After using journald (and systemd) for a couple […]