An application model is a graphical representation of a business or IT application, and the relationship of the infrastructure components (that is, devices and groups) that are required to support or provide functionality to the application. A device is any computer that needs to be managed in order to deliver an IT application, and a group is a selected set of devices or monitors, determined by your operating needs.
Before you begin with application models, ensure you have performed the following procedures:
- or or both
The following figure is an example of an application model:
Manually created application models
In the TrueSight console, an application specialist can manually create application models using devices and groups from TrueSight Infrastructure Management, or devices discovered by TrueSight App Visibility Manager, or a combination of components. In a manually created application, you can create the model and define the relationships and dependencies between the components. An application that is manually created in the console generates events based on the event conditions that are specified with the devices.
For information about creating applications, see Creating an application manually.
Automatically discovered application models
TrueSight App Visibility Manager automatically generates models for the web-based applications that are monitored by App Visibility agents. As transactions flow between monitored servers—that is, servers with an App Visibility agent installed—TrueSight App Visibility Manager maps out the flow between the application nodes. If a monitored node enlists the service of a non-monitored node, such as a database or messaging service, nodes for these items are added to the application model. The name of an automatically discovered application is based on the application URL.
If your application uses a load balancing server or cluster to distribute operations among several servers with the same business need, TrueSight App Visibility Manager creates a group for the application servers.
The model changes dynamically as the application interacts with nodes, adding new nodes to the application model, and removing nodes from the model after 24 hours of inactivity.
The assignment of an application server as a web or business node depends how TrueSight App Visibility Manager recognizes most of the transactions on the server:
- Web: A monitored server where most transactions are Transaction-type requests, that is, the server is the first to receive transaction requests within an application. For example, a web server that mostly receives end-user transaction requests, or a server that mostly receives requests from a non-monitored component (such as a PHP server), is recognized as a web node.
- Business: A monitored server where most transactions are Request-type requests, that is, the server receives most requests from a monitored server.
For information about fine tuning automatically discovered applications, see Configuring application discovery.
Events and event propagation in application models
An event is an indication of a threshold that has been exceeded, such as for high CPU use or for latency on a transaction on a server. The severity of an event depends on the configured levels of the different thresholds on the node. If an event is associated with a specific device or group, the severity of an event is displayed on the relevant node in the application model. The severity level of a node in the application model is determined by the event with highest severity.
The nodes in application models are dependent on one another. When you create a model, you determine the dependency and whether the event status is propagated—that is, whether the status of a "lower" node influences the status of a "higher" node, and, ultimately, the status of the application. (If you do not connect the nodes, or if events are not propagated, then the node status has no impact on the status of the application.) In an automatically created model, the nodes are automatically dependent and events are automatically propagated.
For information about events and applications, see the following topics:
- Viewing an application model
- Creating an application manually
- Configuring event thresholds (SLAs) for automatically discovered applications
Advantages of application models
Application models in TrueSight Operations Management offer the following advantages:
- Create and maintain application models in the TrueSight console.
- Keep models up to date with TrueSight App Visibility Manager, which adjusts models automatically with your changing environment.
- A single application model represents all the objects in your IT infrastructure. You do not have to depend on any other software to create or view the application models.
- Visualize multiple applications in a single dashboard.
- Perform probable-cause analysis across all objects, across multiple servers, and on a single screen.
- Cross-launch to other TrueSight products to drill-down to the actual cause of the problem.
- Manage events and devices in the context of a selected application.