by Andrew Johnstone
I Spent a little while yesterday investigating why memcached causes problems with multigets returning results and ended up comparing debian vs ubuntu. I tested from virtual machines and physical hardware of relative specs. I have also tried a combination of libmemcached libraries and tuned the tcp stack, however here are some of the results from […]
Currently I have been trying to migrate a 4 node production MySQL database to a blade G5/G7 with vmware ubuntu instances on top of netapp. Typically I would not use a virtual machine nor try to run MySQL on top of NFS, however this needs to fit within the clients infrastructure. Baseline Base line performance […]
One of our clients Gorkana was bought by Durrants. As such I have been working on integrating and merging data. As a result I wrote a script to synchronize data between MySQL and Oracle, which is presently a one way synchronization. The implementation The script(s) to synchronize data was broken into a few scripts. Automatically […]
One of our servers was hacked, 5 days after a Debian Security Advisory. The exploit was executed in two phases, the first to gain access to the system and the second to escalate privileges. The exploit used targeted Exim with a memory corruption issue that allowed a remote attacker to execute arbitrary code as the […]
In: General
16 Jan 2010Updated 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 […]
In: General
2 Jan 2010I 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 […]
In: General
31 Dec 2009Last year I wrote an application to highlight media outlets and their reach (coverage of media outlets), selecting regions within the UK and highlighting aspects of a map. This had many issues where by hitting performance problems of rendering within browsers and also limitations of converting KML to tiles via google. A list of these […]
In: General
24 Oct 2009I 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 […]
In: General
22 Jun 2009I have been migrating a large number of websites and consolidating servers to reduce costs. As a result it is important to ensure that services are migrated smoothly, planned effectively, after which I had a think about aspects to consider prior to migrating services. Planning Make a preliminary checklist of services actively in use by […]
In: General
6 Jul 2006After toying with some XPath’s and a fair amount of XSL lately (& getting lost in XPath), I feel it would be wise to place something here to look back on… Marcus Tucker, introduced me to Stylus Studio of which I am very thankful as XmlSpy didn’t help me to deduce the problem with one […]
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.