Understand Discover -- (draft)

[ananzh]

Discover is an internal plugin in OpenSearch Dashboards core. There are three major functions:

• Select data for your exploration, and then set a time range for that data, search it with the OpenSearch Dashboards Query Language, and filter the results.
• Explore the details of your data, view individual documents, and create tables that summarize the contents of the data.
• Present your findings in a visualization.

Required plugins

• charts
• data: access data from OpenSearch. discover uses data plugin to do filter query and search.
  • $scope.searchSource: construct and run search
  • data.query: construct and run filters, time range query, match query and etc
    • data.query.state
    • data.query.filterManager: manager filters
    • data.query.queryString: query string
    • data.query.timefilter: time range filter
  • autocomplete wired in TopNavMenu
• embeddable
• inspector
• opensearchDashboardsLegacy
• urlForwarding: redirect and navigate to legacy url
• navigation: provide TopNavMenu component
• uiActions
• visualizations: create histogram for aggregate data
• opensearchDashboardsUtils: state manager and state sync service
• home
• savedObject*: loading and saving. discover uses savedObject plugin to save search.
  • a saved object type, called searchSavedObjectType
  • a saved object class, called SavedSearch, with all convenient functions
• opensearchDashboardsReact

Setup and Start Discover

Server

Setup discover

• setup application
  • setup server
    • get plugin dependency tree
      • discover plugins
        • create PluginWrapper
      • process plugin
        • get plugin definition
          • get DiscoverServerPlugin’s imports and modules
            • get uiSettings
            • get capabilitiesProvider
            • get searchSavedObjectType
        • add plugins to pluginService.pluginsSystem
    • setup plugin
      • setup each plugin in the pluginService.pluginsSystem
        • instantiate plugin and call setup function exposed by the plugin initializer
          • instantiate specific plugin
            • instantiate specific plugin instance
              • new DiscoverServerPlugin
          • call specific plugin setup function
            • DiscoverServerPlugin setup

Start discover

• start application
  • start server
    • define pluginStart
      • start plugins in the pluginService.pluginsSystem
        • call start function exposed by the initialized plugin
          • call specific plugin start function
            • DiscoverServerPlugin start

Public

Public setup and start are very similar to OSD server. The entry point is changed to src/core/public/osd_bootstrap.ts. The major difference is that public setup doesn’t need to build the plugin dependency tree.

Core functions

Set data

• Open the main menu. On the navigation, click discover.
• Click the button and set the data.
• Set the time range.

Explore data fields

• Check the available fields in the left side bar. Try search a field by its name.

• Click a field and view the top values.

• Click + button to add the field to Selected fields. Meanwhile, see the doc table changes on the right.

* Each doc table columns on the right has a column header. Column header is able to sort data or remove column.

Search data

Discover can do various types of search using DQL, such as term query, string query, boolean query, date/range query and nested query. To search all fields, enter a string in the Search field. To do a more complicated search, use DQL.

• Enter a search and click Update.

Filter data

• Click Add filter.

• Set filter. Below is an example.

* Save filter. * Remove a filter by clicking the `x` button.

Explore document

• Click the expand button on the left of the table row to view a document with details.

• Click Table/JSON tab, will show a table/JSON view.

• Filter in/out a value

Re-use search result (savedSearch)

• Click Save in the top navigation to save your search. Click Open to open an existed one.

* Enter a title to save. * Re-use your discover and filter * In saved objects, open saved discover * In dashboards, add saved discover ( doc views) * In visualize, create a visualization using saved discover filter.

Visualize field

If a data field can be summarized as metrics, statistics, or other analytics (aggregation), discover allows you visualize it. Click the visualize button. You will be directed to a visualization.

[ananzh]

We have decided to replace Discover. This might just be a reference for document. Close it for now.