If you are trying to improve Time to Interactive (TTI) on your website, you've come to the right article. Much of the delay in rendering a webpage and slow TTI is due to long running JavaScript functions, which are not collected by other monitoring solutions. With Function tracing enabled on your synthetic monitors, you can see the file load timings on the same waterfall as the slowest JavaScript functions on the page. This provides actionable insights to give to your Development Team for optimizations.
Blue Triangle expanded the synthetic single page view and aggregate waterfalls to include function tracing detail. Users can now drill down to see slow functions from the scatter plots in Performance Details to track the functions and timings running behind the scenes. With this information you can find out what scripts are slowing the site down for both typical page loads and outliers.
The aggregate waterfall views also highlight when functions are exhibiting chronic slowness. Historically, our users have been able to quickly see if slow files and objects are slow on the page using the Domain and Object-Level Detail Aggregate Waterfalls. This works great for speeding up important page metrics like page onload, first paint, DOM Interactive, and others. TTI is a different story and requires visibility into what JavaScript functions are running slow.
In the example below, you can see a time gap in the file loads as a page renders in the following file load waterfall. Most web developers understand that this is browser rendering and JavaScript function activity, but until now you had to go to Chrome Dev Tools to figure it out if you are lucky enough to be able to repeat the problem.
This is where Synthetic Function Tracing comes in. Our Function Tracing measurements now collect the slowest JavaScript functions, and we can see what’s happening between those gaps:
With Blue Triangle’s Synthetic Function Tracing users can site function calls, view the time the function runs, and optimize any redundant or long-running scripts.