The Do not strip the “www” prefix from URLs check box allows you to specify whether the appliance includes the www prefix in URLs that are recorded in the database and displayed in the user interface.
By default, the www prefix does not appear in URLs displayed in the Site, Page, and Hit categories. By omitting the www prefix, the lists of URLs that appear in the Page and Hit categories are simplified.
However, when your Foglight Experience Monitor is deployed alongside a Foglight Experience Viewer you may want to enable this option. Sometimes the Foglight Experience Viewer needs to retrieve GIFs, JPEGs, and other page components directly from the site that is being monitored. Without the www prefix, Foglight Experience Viewer cannot download and display page components directly from the site in order to provide a realistic playback of a user session.
The Ignore 401 codes during NTLM authentication check box allows you to specify whether or not the appliance includes 401 error codes in metrics such as Response Codes. By default this option is enabled.
The NTLM protocol uses a challenge-response mechanism for authentication. It consists of three messages, commonly referred to as Type 1 (negotiation), Type 2 (challenge), and Type 3 (authentication). During the authentication process, 401 errors can be returned from the server. The client browser then performs an auto negotiate in the background and then establishes the session with the server.
When 401 error messages are generated during this type of situation, they are collected by metric categories, such as the HTTP Fault Log, and may give a false impression that there are problems that requires addressing.
The Exclude redirections from metric calculations check box allows you to specify whether or not hit retrievals that are based on redirections are excluded from metric calculations. Requests for hits can sometimes be redirected for a variety of reasons, each of which are represented by the HTTP 300-series response codes.
As an example, web browsers can make conditional requests for a resource by the request headers they include. If a server responds with 304 Not Modified, the browser can then use its locally cached resource rather than downloading it again from the server.
In general, it is recommended that you select this check box (the default setting) to exclude values incurred by redirections from any of these metrics. This ensures the metrics are not distorted by the inclusion of values from redirections or browser cache accessing, and instead they reflect activity that resulted from a full download from the site the appliance is monitoring.
The Use HTML parser for page recognition check box allows you to enable an algorithm for page recognition that relies on parsing of HTML. The algorithm searches for the presence of the <HTML> tag to determine if a hit is actually a “Page”. This algorithm also searches for the <FRAMESET> tag and, if present, it does not mark the hit as a “Page”.
If this check box is cleared, the system uses an algorithm for page recognition that utilizes a set of heuristics rather than HTML parsing. This technique requires fewer CPU resources, but is not as accurate as the HTML parsing algorithm.