Version 4.1 User's Guide
What is PageSentry?	Previous | Next Contents

Web sites, e-mail, AppleShare servers, and other Internet resources are no longer merely useful productivity tools. For many organizations, these services have become a crucial part of day to day operations. Server downtime is simply not an option, so monitoring servers to detect and report failures has become critical.

Of course, the only sure-fire way to know that a server is performing perfectly is to use it like any one of your users would. To test a Web server, accessing a page using a browser leaves no doubt that the server is running. Likewise, logging into an AppleShare server and copying a file verifies that it is functioning as it should.

PageSentry is the "virtual assistant" that periodically performs tests by mimicing real Internet client activity to verify that every aspect of your site is functioning perfectly. If any test ever fails, PageSentry can take a number of actions to warn you, or it can attempt to correct the problem itself with no user intervention.

Put A Sentry On Duty

To monitor any server with PageSentry, you first create a Sentry to periodically test the server. PageSentry can create Sentries that perform high-level client tests of HTTP, SMTP, DNS, FTP, Telnet, AppleShare, POP, IMAP and other servers. You can also use the Stream and Connection Sentry types to monitor other TCP/IP servers that are not directly supported by a high level Sentry. In addition, a Ping Sentry allows you to perform an extremely low-overhead test of any TCP device on the Internet. Ping tests are not as thorough as the complete client tests provided, but are perfect for testing network connections and low-level devices like routers and gateways. Finally, PageSentry's Process Watch can be used to monitor any application on any Mac, anywhere on the Internet.

Take Action

When a Sentry detects a server failure, it runs any number of Notifiers. Notifiers can be configured to send e-mail, send a page (using PageNow! alphanumeric paging software), restart your server (using a PowerKey Pro intelligent power strip), run Telnet "scripts", trigger Web processes, and more. Notifiers can also send an AppleEvent to a script or another AppleEvent aware application, allowing PageSentry to take virtually any action imaginable to get your server back to work. Notifiers can be set to tell you when servers return to service, delay action to prioritize alerts, or be scheduled so that a suitable action is taken at the right time of day or day of the week.

More Than Pinging

For 100% reliability, TCP "pings" just are not enough to tell you that your Internet servers are running properly. For example, PageSentry monitors your Web server by actually downloading a specific page from your server and checking for a specific text string. This method of server monitoring has far more benefits than just pinging your server. A ping, or echo, will just tell you that the machine is running and TCP/IP is working. With PageSentry, you can be sure that your server is actually serving pages. You can also make sure that your CGIs (like NetCloak, Lasso, etc.) are working by testing the content of your pages, image maps and search engines.

Monitor Multiple Servers Anywhere

Since PageSentry works by making TCP/IP connections, you can check any page, on any server, anywhere on the Internet! If you operate several servers, you can have a separate Sentry to check each server. You can also check multiple pages on the same server, or any combination in between.

PageSentry also gives you an extra level of reliability by "monitoring the monitor" using the Pulse Sentry. The Pulse Sentry sends you a message, or "pulse", at a regular interval saying "I'm on the job!", making sure you know that it is up and keeping an eye on your servers. As with the other Sentries, notification can be by e-mail, pager, or another AppleEvent-aware application.

"Monitoring the monitor" is taken a step further with built-in support for Sophisticated Circuits' Rebound! and Kick-Off! products. PageSentry will automatically tickle either the Rebound! or Kick-Off! once each minute, so that if PageSentry should ever fail, the monitoring Mac will be automatically restarted. In short, PageSentry provides extremely robust testing of your critical servers, while using these 3rd party tools to make sure that your safety net is always working perfectly.

Copyright © 1995-2002 Maxum Development Corporation http://www.maxum.com/ Rev. 7/10/02	Previous | Next Contents