Foglight 7.1.0 - Web Component Tutorial

Queries

In Foglight®, queries are the preferred method for retrieving data from a data source. For example, you can set up a query to retrieve a list of objects that represent all agent instances running in a monitored environment whose host name matches the name of a particular Host object.

NOTE: You can also retrieve data in a more limited way using a Data binding object and you can use the context mechanism to get data from other views. It is also possible to use functions to return data.

The objects that appear in the Data menu choice under Configuration are those that are returned by root queries. A number of default Root Queries have been defined. These allow you to browse the common data objects. Using this approach you can build your own query that returns objects of interest to you and drag them on to your custom dashboard to create pages that meet your specific needs.

NOTE: You can build your own root queries. Simply enable the UI Query check box in the New Query definition editor.

These topics discuss how to work with query definitions and provide explanations of the choices a user encounters.

Overview of Query Definitions

Queries let you select a set of data objects of the same type. Pages and views extract and use data from the queries for values and context settings.

Each query defines:

Optionally, a query can search from the root, drilling down until it finds objects of the desired type. In addition, it can restrict the objects it finds using conditions (or restrict them to the first N objects), it can sort the objects, and it can aggregate the objects into maximums, minimums, averages, and other aggregates.

Queries return a list of data objects of the same data type (such as Host or Alarm). For example, a query on the Host data type may return a list that contains all the available Host data objects from the data source.

Queries always return a list of data objects. Even when there is only one object found that satisfies the query, the result is a one-element list. A query that does not find any objects returns an empty list.

Just like Views, Relevant and Allowed Roles can be set on Query Definitions. These are taken into account when filtering Root Queries by role in the Data Browser and when using Create dashboard or Create report. For more information, see Roles in Query Definitions.

Creating a Query in Foglight

You begin the process of creating a query by clicking the Add button after selecting Queries in the drop-down list in the Module Contents pane. The Add Query dialog box appears with these choices:

NOTE: For more information about these functions, see View Commands in the Definitions Area . For more information about configuring queries, see Query Definition Settings .

Query Definition Settings

Unlike views, a query definition does not have separate tabs for different groups of settings. All of the settings are on a single page.