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Tips for Stress Testing - Make Sure You Are Prepared for the Holidays #HolidayReadiness


Peak traffic from flash sales or new product launches can be problematic for many retailers during the holidays. With holiday season sales representing 25-35 percent of revenue for many retailers, getting your site prepared for peak can significantly affect your holiday revenue. A website's ability to deliver a great customer experience during peak can hinges on three key areas - infrastructure, application code and CDN configuration.

Though the holidays are still a few months away, now is the ideal time to run a peak threshold load test to determine how many users or how much traffic load you can have on your site before it becomes unresponsive. In a perfect world, everyone would have a staging environment that exactly mirrored their production environment to run this test on but that's not the case for many retailers. First things first for those running tests against your production environment -- make sure you coordinate with your IT teams, datacenter and CDN before and during testing to avoid any interruption to customer traffic. Without proper coordination, you could inadvertently cause a DDoS of your own website!

When running tests on your site, they should be done in patterns that real users would use to access the site. Here are a few key tips when stress testing your site:

1.     Utilize usage patterns from your analytics to build the flow through the site from product browsing, add to cart and checkout. 

2.     Apply analytics to define the most common regions and connection speeds users are experiencing for a more accurate assessment. 

3.     When calculating the expected traffic load for your site, take the following criteria into consideration - last years' peak traffic, upcoming marketing campaigns and then add in an additional cushion of 10-20 percent to cover for unexpected traffic patterns. The following monitoring and results will help you understand if your architecture is properly sized for the expected load.

      Hardware monitoring can highlight issues with CPU, disk and memory utilization as well as connectivity between web and database servers.

      Monitor for single points of failure that can cause serious performance issues such as routers, firewalls and internal proxy servers.

      Application monitoring can be used to spot long running queries, over utilization of processes and how many calls per minute the application can handle.

      CDN configuration is key to offloading traffic from your origin infrastructure to the edge of the Internet. Configuration of cache times and objects can allow you to offload up to 100 percent of your static assets and dramatically reduce the load on your infrastructure. Dynamic site acceleration and adaptive image compression can be used to optimize for fast changing content (like personalization) and inline image compression to help optimize the multi device experience.

4.     Verify that your third party vendors are able to handle the additional load. If your testing or personalization vendors can't keep up with consumer requests, you could end up showing pages with empty or missing content. Even worse, some third party tags can slow down your site or block your entire page from loading if the tags are not properly implemented and using asynchronous calls. Tag management solutions can help you monitor these issues, as well as quickly disable poorly behaving tags without the need to make code level changes to your website.


In addition to an increase in consumer traffic, the holiday season brings a sharp increase in attack traffic. Last year during Black Friday, the Akamai Intelligent Platform saw an increase of 2.5 times the number of attacks compared to the previous four Fridays. There has also been an increase in the number of DDoS attacks based on extorting bitcoin, which you can read more here. So while you are stress testing your site, it's important to make sure that you also have a solid cloud-based web application firewall and DDoS mitigation platform in place.


Jason Miller is Akamai's Chief Strategist of Commerce.