Performance Monitoring: The Top Online Travel Websites

by | August 22, 2012

With Labor Day still a couple of weeks away, and record-high temperatures scorching parts of the U.S. and Europe, summer is a long way from over. This is good news — if you haven’t yet exchanged your suits and heels for swimsuits and a pair of flip-flops, you still have time.

And we can help. Since the start of June, Apica has been tracking the website performance of some of the web’s most popular online travel sites, so you can decide where to go to book your next trip the fastest. Using our browser monitoring, we conducted checks every 30 minutes from our eastern U.S. monitoring locations.

If you’re looking for a stable, reliable, and fast user experience, check out Travelocity, Kayak or TripAdvisor. Over the past couple months, these sites delivered the exacta of web performance – availability over 99 percent, and response times less than four seconds. Jetsetter is a good option as well, delivering 99.86 percent availability and just about four-and-a-half second response times.

In contrast, Airbnb has displayed the worst web performance this season. Since June, Airbnb has been just 81.03 percent available. When the site has been up, it’s been moving slowly, delivering 13.60-second response times and an overwhelming number of “waiting for response” errors. The graph below depicts Airbnb’s availability and response times over a one-week period. (Note: response times shown in graph are in milliseconds.)

From the looks of it, Airbnb’s availability and speed troubles appear to stem from a lack of optimization. Understandably, the site contains many images. After all, who wouldn’t want to first see the home or apartment you’re thinking about renting? But large images and large quantities of images are taxing and can have a negative impact on site performance.

Typically a developer will use a Content Delivery Network (CDN) to help relieve some of this burden. The CDN works as a local (geographical) cache of static content, thus shortening the response time for the users. In some cases, when the site’s customer base is spread out across a wide geographic area, several CDNs might be used.

In terms of Airbnb, it appears that a CDN is in use but is responding slowly. See the chart below. Here are the 10 worst URLs for Airbnb during a period of poor web performance. Almost all of them come from the same source. The .muscache is probably a CDN network used by the site, and the a0, a1 at the beginning are probable the catalogs where the different objects are stored. Click on the picture to get a more detailed view of the performance situation in a waterfall graph.

To determine if Airbnb’s issues were specific to the East Coast or indicative of broader performance issues, we conducted an additional test on this site from our U.S. West monitoring location. But we encountered the same problem from this data center as well. As a result, we’d recommend that Airbnb (or any site experiencing this issue) evaluate the CDNs in use and optimize them.

End users’ expectations for how long a web page should load aren’t going to ebb. If anything, users are going to continue to expect a faster and faster user experience. Companies that supply real-time information need to realign their performance goals with these expectations and put in the work on the back end, including a review of any CDNs in use, to give users the smooth, quick experience they’re looking for.

Apica Product Team