dbMonitor is a tool for monitoring and analyzing database operations in applications that use dotConnect for MongoDB. It provides a visual interface for tracing database events in desktop applications, ASP.NET applications, and Windows services.

dbMonitor tracks database events for individual components, including opening and closing connections, connection pooling, command preparation, and command execution. For command events, it displays the command text:

• When the Sql Engine connection string parameter is set to true (the default), dbMonitor displays the original SQL statement.
• When Sql Engine is set to false, dbMonitor displays the native MongoDB command in JSON format as sent to the server, including the added maxTimeMS field.

For example, an application that executes a parameterized SQL query followed by a native MongoDB count command generates the following events:

Connect: Open connection: "Host=localhost;Port=27017;Database=sample"
Prepare: Prepare: SELECT name FROM customers WHERE name = :n
Execute: Execute: SELECT name FROM customers WHERE name = :n
Prepare: Prepare: {"count": "customers"}
Execute: Execute: {"count": "customers", "maxTimeMS": 30000}
Disconnect: Close connection

dbMonitor Features

dbMonitor provides the following features for viewing, filtering, and analyzing database activity.

Events Grid

The Events grid displays traced database events, including their descriptions, timestamps, durations, and statuses. You can sort events by clicking a column header. When you select an event, the SQL, Parameters, Error, and Call Stack windows display additional information about it.

Event Details

The event details area contains four windows:

• SQL: Displays the SQL statement associated with the selected event.
• Parameters: Displays the parameters and their values for the selected SQL statement.
• Error: Displays error information associated with the selected event.
• Call Stack: Displays the call stack of the function that initiated the event.

Select an event in the Events grid to view its details, and switch between the windows to inspect the available information. To open a specific window, select the corresponding command from the View menu.

Processes Window

The Processes window lists monitored processes and their current statuses. Select a process to display its events in the Events grid. When an application closes, its process is marked as Terminated. Its event log remains available for viewing or saving to a file.

To remove a terminated process, use one of the following methods:

• Right-click the process and select Delete Inactive.
• Select the process and click Delete Terminated Process on the toolbar.

Object Tree Window

The Object Tree window, located below the Processes window, displays monitored objects in a hierarchy:

• All Objects: The root node containing all monitored objects.
• Connection objects: Nodes representing individual database connections.
• Other objects: Nodes representing objects associated with each connection.
• Pools: A separate node grouping connection pools.

Select a node to display events associated with that object and its descendants. This lets you filter events by connection, object, or connection pool.

Call Tree Window

The Call Tree window displays the combined call stacks of database events for the selected process. You can use this window to filter events by the functions that initiated them. Select a function in the call tree to display only events initiated by that function or its descendants.

Remote Monitoring

dbMonitor supports remote monitoring, letting you trace database operations in applications running on another computer. For the configuration steps, see How to Monitor an Application Remotely.

Unicode Support

dbMonitor supports Unicode, letting you monitor applications that work with international character sets.

You can switch between monitored processes, explore object hierarchies, and inspect database events during application execution. dbMonitor is designed to minimize its impact on application performance. Monitoring is also available at design time.

How to Monitor an Application with dbMonitor

To enable monitoring in an application that uses dotConnect for MongoDB:

1. Add a MongoDBMonitor component to your application. You can drag the component from the Toolbox onto a form or create it programmatically. Only one MongoDBMonitor instance is required per application.
2. Set the MongoDBMonitor.IsActive property to true.
3. Start dbMonitor before running your application. If dbMonitor is installed, you can launch it using the Run dbMonitor command in the MongoDBMonitor component designer or from Tools > MongoDB.
4. Run your application to begin tracing database operations.

How to Monitor an Application Remotely

To trace an application running on another computer:

1. Enable monitoring in your application as described above.
2. Set MongoDBMonitor.Host to the host name or IP address of the computer running dbMonitor.
3. Set MongoDBMonitor.Port to the port used by dbMonitor (1000 by default).
4. In dbMonitor, under Options > General, configure the same port.
5. Start dbMonitor and run your application to begin tracing events.

How to Optimize Monitoring Performance

You can reduce monitoring overhead by disabling call stack collection and filtering the events sent to dbMonitor.

• Disable call stack collection. Collecting and transmitting call stacks can affect application performance. If you do not need call stack information, set the MongoDBMonitor.SendCallStack property to false.
• Filter monitored events. To reduce the number of events collected, use the MongoDBMonitor.Filter property to specify which event types to monitor. For a list of supported event types, see MonitorEventFilter.

See Also

MongoDBMonitor Class  | Devart.Data.MongoDB Namespace