HTTP redirections can impact your web services performance! This is important to monitor them.
Let's take the example of an HTTP session (http://www.kadiska.com) redirection to the corresponding secure HTTPS session (https://www.kadiska.com). From a timeframe standpoint, you see on the picture below that the first HTTP connection is fully embedded in the Redirect time of the HTTPS connection. It means that the initial HTTP session metrics (DNS, TCP, Server and Transfer) are not available as such. Their potential impact on performance is included in the Redirect time of the corresponding secure connection. The initial HTTP connection is not reported.
The following blog article provides detailed information about the redirection types, behavior and potential performance impact.
The time it takes for the browser to perform a redirection corresponds to the Kadiska Redirect metric.
As shown on the W3C Time Navigation API view hereunder,
Redirect time =
In order to see the details between "Redirect" and "Wait" metrics, you must select either the "Breakdown" or the "Breakdown(Detailed)" view of the "Navigation" measurement, as illustrated below.