Last week we launched our Real User Monitoring (RUM) service, and the response has been fantastic. Our customers have added RUM to scores of websites, and we hope the data collected can help you get a better understanding of the performance of your sites.
We already have quite a bit of information about Real User Monitoring, but today we wanted to address one feature in particular: the long tail of load time distribution.
Web performance is important
First of all, let’s agree that web performance matters. In fact, it’s increasingly important as visitors to your websites demand more and more. The site should not only look good and be easy to use, but also load fast.
“Subconsciously, you don’t like to wait. Every millisecond matters.”
That’s what Arvind Jain, Google’s “resident speed maestro,” told the New York Times.
In the same article, we could read: “People will visit a Web site less often if it is slower than a close competitor by more than 250 milliseconds.” So you want to make your site fast, and faster than your competitors.
In an interview last year with Jain you can read much more about web performance.
The long tail
Every visitor will have a different experience of your website. Depending on where they are, what device they use, what kind of connection they use, etc.
Do you know how the page loads of your website are distributed among its visitors? If not, real user monitoring can show you how fast the site loads for all visitor. This includes everything from the users for which the site loads the fastest to the long tail of users that see slower loads.
This is a great example of when real user monitoring can show you the whole picture of your site’s performance and indicate to you where you can start looking for ways to tweak the performance or solve performance problems.
For example, look at this load time distribution chart (you can see a similar chart for your site on the RUM > Summary page in my.pingdom.com):
The scales for both axes in the load time distribution chart are dynamic, so they will adjust to the specifics of your site.
You can clearly see that most visitors during this particular time period experience a fast site, with load times of two seconds or less. Then follows a long tail of different load times, in this case up to 16 to 17 seconds. Clearly the users with load times that long will not enjoy the site.
And the further down the long tail you get, the likelier it is that those users end up going to another site rather than staying on yours to buy things, read articles, or interact with other users.
In other words, the long tail is worth money. That means that the more you can improve the performance of your site, the more likely users are to stick around for longer. Real User Monitoring can be an important tool in helping you figure out where to start looking.
For more on the long tail, watch John Rauser’s presentation “Investigating anomalies” at Velocity 2012.
What to look out for
Here are some things you can look out for when dealing with your site’s performance long tail:
Load times vary over time and can be caused by a lot of factors, some outside of your control. Also, the load time distribution looks different on all sites.
Keep an eye on the extremes of the load time distribution. Both the fastest as well as the slowest pages may simply not be working as they should. Also, really fast pages are often error pages. Little content = fast load time.
You should have synthetic monitoring in place for situations when the site is down because RUM depends on real users actually visiting your site. No visitors = no RUM data.
Once you have identified a page that is not working as it should, dig in deeper with a tool such as our Full Page Test, which can show you a waterfall chart. With the waterfall chart you can further diagnose what causes the page’s behavior at load.
If your website relies on multi-step or multi-page transaction flows, use something like Transaction Monitoring to make sure that the all the steps in the transaction execute properly.
Real user monitoring: a tool in your web performance toolbox
Hopefully you now have a better idea of what real user monitoring can offer you in terms of identifying possibilities for speeding up your websites, especially by looking at the long tail. This is just one feature of RUM and there are of course other ways you can analyze your data.
We hope that you take our Real User Monitoring service for a spin, and we’re confident it will become an invaluable tool in your web performance toolbox. If you don’t already have a Pingdom account, you can sign up for one here.
We will be back soon again with more articles about real user monitoring, including practical tips of how exactly RUM can help you identify performance issues with your sites.
Finally, you may want to join one of our discussions about Real User Monitoring to learn more and share your experience.