Imperva Cyber Community

Slow page load times can stop an online business in its tracks.

Many website owners already know that that page load speed is one of Google’s top ranking factors. It’s also a critical element of good UI design – nothing frustrates users quite like a slow website.

But as web technology improves, so do user expectations when it comes to website features. This is especially true when it comes to cybersecurity, where the number and sophistication of technologies is growing at a rapid rate.

This is why slow page load speeds can be such a persistent problem. Website owners need to provide a continually improving user experience without sacrificing performance. Imperva engineers work constantly to optimize our security processes to improve page load speed for our customers.

What Is a Good Page Load Speed?

One of the best ways to measure page load speed is as a function of the average bounce rate at a particular speed. The slower a page loads, the more likely users are to give up and look for faster content elsewhere.

According to Google, the bounce probability for the average web page increases by 32% when the page takes between one and three seconds to load. That figure jumps to 90% for page loading times of up to five seconds, and continues onwards from there.

A safe goal for any commercial website is under three seconds. 40% of consumers will leave a commercial webpage that takes longer than this amount of time to load.

How WAF Technology Impacts Page Load Speed

Web application firewall (WAF) technology is a powerful security tool that can add multiple security elements to a website. There are two popular types of WAF service on the market, and choosing the right one is important for optimizing page load time.

• Hosted WAF solutions are part of your website infrastructure, often in plugin form. For instance, Wordpress users can install a hosted WAF plugin that examines incoming traffic and blocks illegitimate requests.
• Cloud-based WAF solutions (like Imperva) sit outside the user’s network infrastructure. The security vendor examines and blocks traffic using its own network and only allows safe requests to pass through.

Since hosted WAF solutions use website resources to perform critical security tasks, they necessarily weigh down performance. Cloud-based WAF services do not suffer from this problem.

This is one of the reasons why the owners and administrators of large commercial websites look for reputable cloud WAF providers. Offloading the task of examining and blocking bad traffic to a security provider allows both parties to optimize their infrastructure for dedicated tasks.

How To Troubleshoot Slow Page Load Times with Imperva Cloud WAF

Despite the speed advantages that cloud WAF users enjoy, many still face obstacles when it comes to fast page load performance. Fortunately, Imperva users can benefit from the Imperva Community’s insight to solve page load problems. 

1.    Enable Smart Caching

Imperva cloud WAF technology supports smart caching. Cached content loads much faster than uncached content, so maximizing the amount of content you can safely cache will dramatically reduce server burden.

Smart caching allows Imperva to dynamically profile web traffic and identify cacheable static resources. This way, the ratio of cached assets to uncached assets improves without requiring you to add cache directives at the origin.

Imperva’s smart caching technology will cache any resources requested by five different IPs within a one-hour window, provided that the server returned the same resource for every request.

2.    Verify Your Website’s CNAME Redirection

 Many web users don’t know that the “www.” in front of many website URLs can play an important role determining page load time. The most common example – when “example.com” and “www.example.com” point to the same exact application hosted on the same server – is not necessarily always the case.

For Cloud WAF users, for instance, the Canonical Name (CNAME) of a website should point to Imperva’s servers. Otherwise, multiple redirections must take place in order for Imperva to validate incoming traffic and ensure only legitimate traffic reaches your servers.

In short, you must make sure your “www.” URL points to the Imperva CNAME. You should not direct that URL to your IP address.

3.    Make Sure Users are Being Served from the Closest Data Center

 When users type a URL into their browser address bars, the request has to follow a labyrinthine circuit – often across the globe – in order to obtain and present the requested data. The longer the path that data must follow, the longer it will take to do so.

Most web browsers and servers automatically find the shortest route to the assets users request, but this is not always the case. Improper configuration can make the round trip travel time much longer than it needs to be.

You can quickly verify where the data center your website data is being served from. Simply add the following string to the end of your website’s naked domain:

/_incapsula_resource?NWQ=1

The resulting page will tell you where the traffic is coming from. If the location it shows is not on the same continent as the device you are using to access the website, contact our support team to resolve the issue.

4.    Send a Traceroute Request to Imperva

 If your website still isn’t performing according to your expectations, you can send a traceroute request to Imperva and have one of our technical staff work with you on options that can further improve page load times for your website. 

 Simply run a traceroute on your PC (here’s how to do it on Mac OSX) and send a screenshot of the results to our support team. We’ll walk you through the process of identifying networking issues that are dragging down your page load time.