IntelliJ IDEA 2021.2 Help

Run notebooks and analyze data

To preview and analyze data sets, you need to run the executable paragraphs of your notebook.

Running notebooks

You can run paragraphs one by one or all at once. When executing any paragraph, mind code dependencies. If, for example, the current paragraph relies on the variables that are initialized in the previous paragraph, it needs to be executed first.

  • Click Run all on the notebook editor toolbar to execute all paragraphs of the notebook, all paragraphs above or below the current one. The progress of the execution will be shown on the toolbar.

  • Click Run a paragraph icon in the gutter to execute a particular paragraph of the notebook.

Once the execution completes, the execution status is shown in the toolbar and in the gutter:

  • Finished: success: execution has been successfully finished

    You can click this icon to execute the paragraph again.

    Run a paragraph

  • Finished: failed: execution has failed

  • Finished: aborted: execution has been aborted

In case of the successful execution, preview the output that is shown below the paragraph code.

Executing code paragraph has been successfully finished

The Spark job link appears in the preview area when the paragraph contains any RDD operation that starts a Spark job, for example, count or saveAsTextFile methods. Click this link to open the Spark Monitoring tool window and preview the completion status, event timeline, and DAG visualization.

You can select a Spark job code in a notebook and extract it into a Scala file for further usage.

Extract a Spark job

  1. Select a Spark job code fragment in the notebook.

  2. Right-click the selected code and select Refactor | Extract Spark Job from the context menu.

    Extract a Spark job

  3. Specify the Scala filename and its location in your file system, then confirm your choice. The specified file with the extracted job appears in a separate editor tab.

    Extracted job is opened in a Scala file

Refresh interpreters

When you execute code of your notebook, you might want to restart an interpreter on the target Zeppelin server. For your convenience, IntelliJ IDEA provides several options to do this:

  • Click Interpreter settings on the notebook toolbar.

  • Right-click the Run icon in the gutter and select Restart Interpreter.

    Restart Dart Analysis interpreter from the gutter

  • Right-click any paragraph in the editor and select Restart Interpreter from the context menu.

When you execute SQL statements or run the show method of a Zeppelin or Spark object, the results are shown in the Table and Chart tabs of the preview area.

Viewing outputs

If your notebook processes data collections, you can preview output both in tabular and graphical forms. You can manage the output presentation by selecting a table, graph, or split view. Hover over the right side of the paragraph output to see the corresponding controls.

Switching between the output views

Organize data in the table

  • Click a column header to order values in it.

  • Click Filter data to filter data in the selected column.

  • Click Pagination to organize table in pages. Toggle this button and specify the number of table rows to display on a page: 10, 15, 30, or 100.

  • Click Configure table columns and select the columns to be shown in the table.

Car data in the table view

Export tables

  1. Click Export table to save the table in a .csv file.

  2. Enter the filename and click Save.

The default type of the chart is defined by the chart settings on the server. However, you can configure and modify the predefined chart type.

Configure charts

  1. Click Chart settings icon to alter the initial settings of the chart.

    Chart view

  2. Click any icon that corresponds to a chart type and the new chart will be plotted. For example, click Scatter chart icon to add a new scatter chart.

  3. Drag the columns you want to plot to the specific field:

    Building a new chart

  4. Click the Add new series link to add more series to the chart. Then drag the required columns to the target fields to set the axes.

Export charts

  1. Click Export a chart to save the generated graphical output in the .png format.

  2. Enter the filename and click Save.

Configure chart settings

  1. To define the way the chart looks, click chart settings on the chart toolbar (right side of the output area).

  2. Select the contrast or default theme. Click edit the theme to modify the theme colors. Also, you can click clone the theme to clone the theme and customize it later.

    Chart settings
  3. Review the modified settings in the preview area and save the changes.

Viewing variables with ZTools

With an experimental feature, ZTools, you can preview local variables for the current Zeppelin session. ZTools is a Java library that establishes a protocol between the Zeppelin server and the IDE, and provides runtime information to get more details about the variables, and offers smart coding assistance.

  1. In the Zeppelin connection settings, select the Enable ZTools Integration checkbox.

    Enabling ZTools

  2. Download the ZTools library from https://dl.bintray.com/jetbrains/zeppelin-dependencies/org/jetbrains/ztools/ztools-spark-all/0.0.13/ztools-spark-all-0.0.13.jar.

  3. Specify the downloaded library as a module dependency for the target Zeppelin connection. See the detailed instruction in Configuring dependencies.

    Note that you must have permission to load Zeppelin dependencies. If you don’t have this permission, the Zeppelin server administrators must add the dependency on their side.

  4. Open any notebook on the target Zeppelin server and execute any paragraph to collect data.

  5. Once the paragraph is executed, the Variables tab appears in the Zeppelin tool window. You can also see the ZTools synced status in the notebook toolbar.

    View variables in Zepplin tool window
  6. In the Variables tab, you can preview the values of the variables. You can right-click any variable to open a context menu and inspect the variable in a separate window with the Inspect ... command, or preview its value in text form (View Text).

    Inspecting a variable

    At any time, you can click Refresh connection to sync up with the server.

With code assistance that the ZTools library provides, you can complete the exact names of columns in the SQL code. You can also check that the names of your columns do not contain any errors (for example, references to columns that do not exist). Start typing any pattern matching the column name, and you should expect to see code completion:

SQL code completion with ZTools

Troubleshooting

If, for some reasons, the execution of the notebook or a particular paragraph has failed, review the error message and consider some typical troubleshooting actions:

ProblemRecommended action
The notebook toolbar is not available. The following warning message is shown: The notebook is not connectedClick the Try Reconnect link to get the notebook connected to the server.
Server connection is lost. The corresponding icon shows the disconnected status of the server:
Disconnected server
Click Refresh connections to reestablish the connection to the server.
Interpreter session gets expired. For example, the error message reports that the Spark session is expired.Click Interpreter bindings on the notebook toolbar control and restart the problematic interpreter.
Last modified: 14 October 2021