Version 2.5 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, and AppleShare servers. You can also use the "Stream" Sentry type 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.

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), or restart your server (using a PowerKey Pro intelligent power strip). 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 also 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, MapServe, or AppleSearch) 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 can notify you via e-mail or AppleEvent-aware applications if it detects a failure. E-mail notification is the most basic form, but with an AppleEvent interface you can write an AppleScript to give you almost any form of notification. Use a script to connect PageSentry to your paging application, display an on-screen warning, or execute another AppleEvent-aware application.

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.

Copyright © 1995-98 Maxum Development Corporation 820 South Bartlett Road - Suite 104 Streamwood, IL 60107 http://www.maxum.com/ Rev. 2/18/98	Previous | Next Contents