Archive for January, 2010

We hold much of our server configuration within the office, which is restricted down by iptables. As such when spawning new instances on EC2 we need to allow access to our internal network via iptables, to allow nodes to connect to the office and configure themselves. The following script can be run within a crontab […]

I previously described how to configure HA Proxy and ucarp to load balance traffic between servers and share common IP addresses in the event of failure, however this still leaves holes in the availability of the application. The scenario only accounts for availability within a single data center and does not address how traffic and […]

Updated bash script 23/01/2010: The script was assumed to run from EC2 itself, however I have since modified this so its applicable to local environments and made a little more robust. There are quite a number of new tools from EC2, each requiring some form of setup on the server. As a result I have […]

I just read “How to use locks in PHP cron jobs to avoid cron overlaps” and I thought I would elaborate on this and provide some more examples. In order for a lock to work correctly it must handle, Atomicity / Race Conditions, and Signaling. I use the following bash script to create locks for […]

About this blog

I have been a developer for roughly 10 years and have worked with an extensive range of technologies. Whilst working for relatively small companies, I have worked with all aspects of the development life cycle, which has given me a broad and in-depth experience.