Here is a subject that does not get enough attention. With RHCS/CMAN, the heartbeat of a node, by default, uses broadcast to let the other nodes know that it is alive and well, and is a member of the cluster. So, in turn, by default we are restricted to using a single network for our heartbeat, and in most cases this is fine… But, what if we want to cluster across multiple networks? Say I have node01 on 10.1.1.0/24 and node02 on 10.1.2.0/24, and I want them to be able to communicate with each other? Well, this is not as trivial a feat as you might assume… In fact, I had to employ some of the finest network technicians (well, not really — but they are pretty smart!) in the south-east to get this to work… Continue reading »

I manage a site that uses Google Apps for hosting their domain services (email, calendar, etc…), and they had a requirement to have the ability to email images to an inbox and have those images automatically inserted into a mysql database, where a forward-facing web application would later display the upload date/time, a comment about the image, and the image itself. The process needed to be fairly simple, but it also needed to use GMail’s SSL ports for pulling down the information (is there even another way to do it nowadays?)… Continue reading »

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