Here is what one of my clients uses to monitor their webservers
http://www.redalert.com/
Kind of a neat service, actually. Features include:
* Offers the flexibility needed to monitor all your Internet
devices; it can handle Web transactions, secure pages, redirection, CGI
queries, POSTs, and authentication.
* Has the ability to determine whether your Web site is delivering
the proper content (ideal for “thank you” pages, etc.).
* Can escalate alarms depending on the error type and the time of
day; Red Alert automatically performs triage on the situation and alerts
the appropriate team.
* Offers triple-checked alarms, which means that Red Alert
responses are reliable with very few false positives or unnecessary alarms.
Beef up your service, and you get:
* Performance of Web Transactions (banking, shopping carts, etc.)
* Changes in Web site content
* Secure page performance
* Redirection sequences
* CGI queries
* POSTs
* Authentication
