The t1.micro instance comes with only 602MB of memory. Especially under high load, it is quite easy to deplete the available memory – and since no swap space is enabled by default, this can quickly lead to a server becoming unresponsive. Swap space can also allow the kernel to move unused data out of memory,… Continue reading Adding Swap Space to an EC2 Instance
Month: November 2011
Shrink EBS Root
My EC2 instances are setup to have only the operating system and program files on the root volume, with all other data (logs, mail, etc.) on a second EBS volume. This leads to a very stable root volume, which sees a minimum of changes. Fully configured, my root volume (using Amazon’s Linux) is 1.2GB. The… Continue reading Shrink EBS Root
Capturing Termination Signals in PHP
Consider the scenario of a PHP script which can be run for a period of time, stopped, and continue its task later on. A common necessity for such a script may be to detect when the script is terminated, and perform some functions at that time. This can be accomplished by having the script capture… Continue reading Capturing Termination Signals in PHP
Installing ApacheBench without Apache on Amazon’s Linux
Having recently switched to a setup with only nginx (and no apache), I found myself wanting to run some tests. As nice as siege is, I rather like ApacheBench (ab). However, I really didn’t want to install all of Apache just to get ab. Quick and Easy Way On Amazon’s Linux, the ab binary can… Continue reading Installing ApacheBench without Apache on Amazon’s Linux
Producing Hydrogen Gas using Sodium Hydroxide and Aluminum
One of my favourite chemistry demonstrations is the combustion of hydrogen in a balloon. It has all the qualities desirable in a flashy experiment, and the actual execution is exceptionally easy – the difficulty, however, comes down to obtaining the hydrogen gas if none is available. This procedure is meant to be conducted in a… Continue reading Producing Hydrogen Gas using Sodium Hydroxide and Aluminum