For those customers using an Apache Proxy Server, you may have noticed that Foglight Experience Monitor had (up until now) ignored the X-Forwarded-Host parameter that Apache so diligently passes. This is no longer the case. You now have the option to use this X-Forwarded-Host as the actual URL of the site you are monitoring. For some background, Apache Proxy Server can be used within your infrastructure to translate and funnel requests (proxy) to various servers within your web farm. This is useful especially in large distributed environments where site URLs change but the target servers' HTTP host headers have not changed. This allows for quick manipulation of the outside URL without a large change effort internally.
Well, how do you monitor your site? If you want to monitor and report with the new, external URL you gave it, you may want to utilize the latest feature of FxM which captures the x-forwarded-host HTTP header field. FxM can now see that one exists, and replace the back-end URL with this host header, even if you are monitoring BEHIND the proxy server.
You may be familiar with X-Forwarded-For from load balancers. FxM has used this for years to capture the IP address of the source user when translated through NAT of a load balancer. This is very similar, but instead for the actual URL host name (e.g. www.somewhere.com). You will find this setting in the advanced options of FxM, version 5.5.8 (latest patch as of May 2011 required).
Jason Trunk is an end-user performance expert with Quest Software and can be reached on Twitter @EarlofURL