Product Reviews

Get the Goods on a Running Server

eMon helps with the daily chores.

eMon is a simple server monitoring tool with excellent flexibility that tracks a variety of parameters. These include a variety of pings—ICMP, TCP/IP, UDP. IPX, NetBIOS—and other yes/no tests: specific file presence, disk space available within criteria, MS SQL, Oracle, and database server availability, HTTP URL access, and NT service state. Other tests include NT Event Log monitoring, where you may specify a condition that will trigger an alert, and checking for external applications running. No agents are installed on monitored devices, since eMon uses "pull" rather than push. Log reporting is readily accessible, as the default reports are formatted as web pages accessed via a built in web server. This means that I could check the reports from anywhere, thus giving me quasi-real time remote reporting. An eMon add-on reporting tool improves on NT error logs by consolidating them and refining the presentation.

Installation proceeded without a hitch and I was easily able to add the long license key. Requirements are simple: Windows 9x, NT 4.0 with Service Pack 6, or Windows 2000. eMon runs either as a service or GUI; note that if you run as a GUI and make changes, you should disable the service at least temporarily. I added multiple servers by clicking on the Add Server button or menu choice and, under General Properties, picked how I wanted to monitor that server ("check type"). When you pick that Check type, an additional tab appears across the top of the Server properties dialog box. This box must be correctly filled in. Click OK and you're done. Other tab choices let me customize the sound that plays when an alert is triggered, how often—both number of days, time of day, and time interval—I wanted the parameter monitored, whether the server should be stopped or restarted, as well as any programs that I wished spawned when the server goes up or down, or an alert is triggered. If domains are separated by routers, you may add the intermediate host so that you do not receive multiple alerts from the other side of the router if the connection ceases to function.

Though not difficult to configure, eMon is a little tedious to set up, especially in larger environments. I entered each server, and each service separately for every item I wanted to monitor. You may highlight a previous server entry and duplicate it to avoid some repetitive typing, but still must pick "check type," server, and the monitoring parameters for each entry. You may group sets of servers or services together in folders; the whole folder changes color if an alert is active. Reporting worked very well, but the displayed information was not much more useful than the eMon display itself. Notification occurs through several means: customizable sound on the monitoring station, email alerts, or pop up messages.

eMon can monitor multiple servers using a variety of tools to ensure their continued operation. (Click image to view larger version.)

The 116 page .pdf manual is very well written and illustrated with profuse screen shots, but contains a few typographical errors. eMon is sufficiently easy to use such that most of us will skip sections of the manual, but there are some not so obvious features and abilities that make reading the detailed configuration chapters worth while.

eMon is not designed to cross firewalls or proxy servers, though you may specify a proxy server username and password for internet access—i.e., to check on a URL or CGI script.. Though event log reporting can include multiple parameters, it cannot use full Boolean logic: you cannot filter out unwanted events.

eMon goes beyond simple connectivity tests and is quite capable if you spend the time setting up all the parameters that make monitoring useful. In my hands, eMon worked very well, and I would recommend it for LAN/WANs without firewalls between segments or more advanced monitoring tools.

About the Author

Douglas Mechaber, MCSE, MCNE, CCDA, is a network consultant and dive instructor and is always on the lookout for utilities that make his life easier, or panulirus interruptus, the California spiny lobster.


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