Development, Analysis And Research

After attaching an EBS volume and rsyncing files to the EBS device the server had a load average of 6 before the server became unresponsive to ssh connections and complained of a broken pipe for ssh.
The server was still responding to http requests and ping, however trying to establish a ssh connection, it connected and [...]

I wrote a few munin plugins to monitor memory, CPU and IO usage per process. After collecting the stats for a few days I noticed that MySQL CPU usage had a constant value of 9.1, however all other processes collected CPU usage correctly..
CPU usage

proc=mysqld
value=$(ps u -C $proc | awk ‘BEGIN { sum = 0 } [...]

We have re-written parts of the default configuration for ucarp & haproxy to run several VIPs on the same interface. This works on debian, however some minor modifications maybe needed for other distributions.
Ucarp implementation
/etc/network/if-up.d/ucarp

#!/bin/sh

UCARP=/usr/sbin/ucarp
EXTRA_PARAMS=”"

if [ ! -x $UCARP ]; then
exit 0
fi

if [ -z "$IF_UCARP_UPSCRIPT" ]; then
IF_UCARP_UPSCRIPT=/usr/share/ucarp/vip-up
fi

if [ -z "$IF_UCARP_DOWNSCRIPT" ]; then
IF_UCARP_DOWNSCRIPT=/usr/share/ucarp/vip-down
fi

if [ -n "$IF_UCARP_MASTER" [...]

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 created [...]

I recently came across a peculiar issue that meant dates and times were causing issues with a product we had developed within Australia. The issue being that within “Red Hat Enterprise Linux Server release 5 (Tikanga)” the date within PHP was being read as EST instead of AEST/AEDT, however running “date” from the terminal or running “SELECT NOW()” from MySQL displayed the correct time.