What is the capacity of your website?

August 23, 2009

This is one of the questions I ask potential clients and usually the response is:

  1. “don’t know” or
  2. “our site can support up to x hundred/thousand concurrent users and there are a number of issues we are trying to iron out”

I was surprised to learn that most prospective clients *don’t know* the capacity of their website or service and have no effective plans in place for when there is a sharp increase in site visitors and it crashes (and “to panic” or “reboot” is not a plan)! It is usually after events like a site crashing regularly that web managers begin to consider what they should do about it, of course by which time it is too little too late as the reputational damage has already been done with those visitors affected.

What do we mean by website capacity?

The website capacity is the number of visitors that it can support with each visitor performing representative tasks (browsing, searching, navigating etc.) within specified Service Level’s.

When is it important?

Sites grow in two directions, with increasing visitor numbers and with the amount of content, both of these increases affect the performance of your site. Increasing the number of visitor could slow down the user experience and your visitors won’t hang around if your site is slow or irresponsive, it takes just seconds to arrive at a website and even less to leave it! Increasing the amount of content could also mean that your website doesn’t scale well and page rendering performance is inadvertently affected e.g. bread crumbs and navigation systems may not be generated as quickly.

So *before* launching your next site ensure that you are reducing risk of service failure by specifying and testing a robust, resilient, scalable and redundant architecture. Knowing that your web site is able to support 100’s of users concurrently and also knowing where the bottlenecks are will inform you:

  1. how and when the service is likely to fail, you will recognise this behaviour when and if it reoccurs
  2. mitigate and reduce risk of service failure, and
  3. allow you to build an appropriate business case to improve ongoing service delivery.

What can you do?

It useful to set a benchmark so you can demonstrate what effects any performance improvements your investment produces, there are usually some quick wins that can make a huge difference to your website capacity and in turn the user experience.

All of our clients now perform “stress testing” and ongoing capacity planning for their projects where service delivery within acceptable parameters is crucial. However this hasn’t always been the case.

Even with baked pages generated by some CMS systems there are a number of opportunities to improve your site capacity, e.g. by optimising your client side cache settings and will significantly reduce the number of connections that a user has to make to download each page.

Do you know the capacity of your website? What would you do if your visitor numbers due to a breaking news story suddenly increased 10 fold? 1000 fold? Could your website cope? Could you cope?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: