10 things that could have prevented the police crime map site crash
The Home Office's new website which promised to map the nation’s crime came unstuck yesterday just hours after its launch, crashing as an estimated 18 million people logged on per hour.
Site errors meant peaceful streets in the UK ranked alongside the worst urban crime zones in Britain, leaving residents venting their fury and estate agents complaining the site could bring down property value.
Stephen Taylor, a developer at Great Fridays in Manchester, gives his Top 10 tips for avoiding the problems which inflicted the £300,000 www.police.uk site.
1) Determine user numbers - before you start you need to know how many users are expected to be hitting a new site in order to gain an average of 'requests per minute'.
2) Determine system scale to cope with demand - if you want to build a system to scale you need to know how much of a scale, so how many requests per second the website will get.
3) Rigorous testing – it's important to find out where contention points (places where things are queueing up in the system) are happening before the site launches.
4) Assess hardware and software requirements - scaling requirements can completely change the hardware and software requirements, which completely changes the budget of the project.
5) Look at how Facebook deal with high user numbers - Facebook developed a whole new file system (the thing that abstracts the 0's and 1's on your hard drive into meaningful things like files and folders) so that they could get high performance for saving and streaming media.
6) Have the right system in place to catch hot spots - you need record enough information so that you can quickly determine hot spots.
7) Don't rely on foresight or past projects - there's only so much foresight you can have, each website is different and needs thorough preparation.
8) Act quickly and have enough resources in place to resolve website problems - you need to be agile and well staffed to work through any recurring problems.
9) Try the site in beta first - perhaps they should have done what Google does and call it a 'beta' website to excuse any failure.
10) Have the best hardware in place – some websites throw more and more hardware at a website thats failing. Planning with the best hardware will stop the need for this.
Taylor said: "It is difficult to test a website that's live, and is only really possible once visitor numbers get high enough. To test a website you essentially need as many users on the site as it launches just to see where contention points are happening.
"It’s always tricky to determine how a site system should scale and its vital to have the best hardware in place before launching a website of this size."