Advanced Monitoring in Application Center 2000

System Monitors. The System Monitors data group contains three data collectors—LogicalDisk, Memory, and Processor. The LogicalDisk data collector isn't properly configured unless you've enabled logical disk counters. (By default, Health Monitor enables physical disk counters but not logical disk counters.) To enable logical disk counters, type

diskperf —yv

at a command prompt and reboot the server. The threshold monitors your hard disk's free space and puts the monitor into a warning state if free space dips below 10MB (by default). However, no actions are automatically configured for this warning state. In the event of a critical state, the action at the data-collector level is to email an administrator. The critical event occurs in the event of a WMI failure. No actions are configured at the data-group level.

The Memory data collector uses the Performance Monitor Pages/Second counter. The threshold for this collection is set at 500 pages per second. If more than 500 pages per second occur, the monitor enters a warning state. In the event of a critical state, which an error in the data collection causes, the action at the data collector level is to email an administrator.

The Processor data collector uses processor-usage performance counters. The threshold is set at 90 percent, at which point the monitor enters a warning state. Again, in the event of a critical state, which an error in the data collection causes, the action at the data-collector level is to email an administrator.

Web Site Monitors. The Web Site Monitors group contains one data collector, which uses the HTTP monitor to query URLs and check response times. You can configure security information into the collector if it's necessary to access the site. Three thresholds are associated with this collection. One of the thresholds checks for response times greater than 30 seconds, another checks for the return of an error code higher than 400 (indicating a failure), and the third checks for a failure in the data collection. All these thresholds change the monitor to a critical state. A change to a critical state fires two actions at the data-collector level: Email an administrator and Log to websitefailures.log. No actions are configured at the data-group level.

Create a Custom Monitor
If you performed a custom Application Center installation, Health Monitor can create sample Application Center monitors as well as monitors for other applications and services, as Figure 3 shows. These monitors are helpful if you choose to install a specific application in your Application Center environment. The System Monitors and Web Site Monitors provide functionality in addition to the functionality that the default monitors provide. All the sample monitors are disabled by default.

If the default and sample monitors fail to provide the functionality you require, you can create a custom monitor. To create a custom monitor, follow these steps:

1. To create a new action, right-click Actions under the server icon in the left-hand pane, then select New. In the resulting dialog box, choose the type of action you need. Select the type of action and configuration (e.g., command-line parameters, email recipient, script name, text file name, event type to be fired).
2. Decide whether you want the monitor to reside on one server or to synchronize across all the servers in the cluster. Right-click Synchronized Monitors or Non-Synchronized Monitors, and choose New, Data Group from the menu.
3. Create the data collector by right-clicking the data group and selecting New, Data Collector. The resulting menu lists all possible data-collector types. Select the appropriate data-collector type from this list.
4. Create the threshold to define the point in data collection at which the monitor changes state, as well as the state it will change to. Right-click the data collector and choose New, Threshold from the menu. Figure 4 shows the resulting Threshold Properties dialog box, in which you configure the threshold. You can access this dialog box later by right-clicking a configured threshold and choosing Properties.
5. Choose the actions that need to fire when the state changes and at what level (i.e., data collector, data group, or server). A parent inherits changes in state; therefore, a change in the threshold will create a change in the data collector, which will create a change in the data groups, which will create a change in the server. You can create actions at each of these levels.

Delve Deeply
Web sites and Web-based applications are becoming standard components of corporate networks, as well as essential pieces of the Microsoft .NET strategy. Application Center provides impressive creation, management, and deployment capabilities for this environment, but to delve deeply into your Web presence, you need Health Monitor's comprehensive monitoring capabilities. Only then will you be truly confident in the availability and performance of your Web environment.