Zoomdata Version

Connecting to Cassandra via Presto

You can connect to Cassandra through the Presto connector which is implemented to query data from a Cassandra data source. The need for Presto is due to Cassandra not supporting the aggregated queries directly. Zoomdata supports Presto versions 0.105 and 0.132.


Before you can establish a connection from Zoomdata to Cassandra, a Presto connector server needs to be installed, configured, and enabled first by the Zoomdata Account Administrator. Figure 1 illustrates the interaction of Zoomdata and Cassandra cluster.

Starting with version 2.3, Zoomdata's architecture has been enhanced to enable the deployment of new connectors as standalone components running in their own process space. To learn more and access the setup instructions, refer to the article Configuring a New Connector Manually .

If the Presto connector icon is not displayed in the Add a New Data Source section, then this connector service needs to be installed and enabled. To enable, log into Zoomdata as a Supervisor. If you do not have this privilege, contact your organization's Zoomdata Administrator for assistance or contact Zoomdata Support.

For guidance on enabling or disabling the data source icon, refer to the article Managing Connectors in Zoomdata .

The table below lists information on the features that are supported by Presto:

Supports Distinct Count? Yes
Supports Live Mode/ Playback? Yes
SparkIt Capable? Yes
Supports Group-by Time? Yes
Supports Multi Group-by Charts? Yes
Supports Histogram? Yes
Supports Box Plot? Yes
Custom SQL Capable? Yes
Supports Last Value? No
Supports Partition? No


For details about what is provided on each page of the connection process, review the article Source Connection Workflow . Depending on your needs, you can either follow the steps in order from start to finish or jump to a specific section in the connection process:


  1. Log into Zoomdata.
  2. Click the Sources menu option.

    Figure 1
  3. Click the Presto connector icon.

General Page

  1. Specify the name of your source and add a description (if desired).

    Figure 2
  2. Click Next to continue to the next setup page.

Connection Page

  1. This page defines the connection source for Zoomdata to be able to access the data source. If this is the first time setting up a connection, then you need to input the necessary credentials. If a validated connection already exists, you are given the option to use it.

  2. To create a new connection, select the Input New Credentials option.
  3. Enter a unique name for the connection (to help distinguish between other connections in this Zoomdata account).
  4. Specify the JDBC URL. Keep in mind that JDBC URL must be in the following format:
    jdbc:presto://presto_server:presto_port/cassandra , where cassandra must be replaced by the value of the connector.name property in the /presto_server_path/etc/catalog/cassandra.properties file.
    Specify user name and password. By default, set the user name to "user". No password is required.
    If authentication has been set up, provide corresponding user name and password. Make sure that cassandra user has enough permissions to run SELECT queries.
  5. Click Validate .
    If successfully validated, the connection is saved.

Figure 3

  1. Click Next to continue to the next setup page.

Tables Page

The Tables page lets you select the schema and table to connect with and provides a preview of the selected table. In addition, caching options and toggling the availability of the fields can be done on this page.

  1. Select the schema and then select the desired table to connect to Zoomdata.

Figure 4

  1. Create a Custom SQL query, if needed.
Zoomdata wraps your SQL query into a SELECT statement. If specific statements inside the wrapped query are not supported by your data source, the query will not be executed.
  1. Toggle the caching options (SparkIt and Caching), as needed.
Spark It capability is planned for deprecation in a future release.
  1. Toggle the availability of the fields, as needed.
  2. Click Next to continue.

Fields Page

The Fields page lets you (1) configure attribute options, (2) create custom labels for the fields in your data source (that will be displayed in the charts), (3) manage the Volume metric, and (4) work with Calculations.

  1. Determine whether the field should be visible or not to the user.
  2. Create unique label names, as needed, for each Label field.
When you create a data source, the specific number of distinct values for the attribute fields are saved in Zoomdata depending on the data sample from your data set. You can filter the data on your chart by these values. While editing a data source, if you want to use all distinct values in the filter (that is from whole data source), click the Refresh button in the Statistics column.
  1. For the Type column, you have the option to edit the field type (although usually you won't need to do this).
  2. For the Configure column, numeric and time-based fields may be edited:
    • Numeric types including Money, Number and Integer - ability to select a default aggregation function
    • Time fields - ability to define the default time pattern and granularity; if the time field provides granularities of hour, minute and second, then a time zone label may be applied
  1. Select fields for Distinct Counts as needed.
  2. Refresh the connection to a particular field, as desired.
  3. Configure Filter Display settings for fields.
  4. Edit the Volume Metric settings, as needed.
  5. Work with Calculations , if available and as needed.
If you are setting up a new connection, the Calculations section will not be available until after the connection is saved.
  1. Click Next to continue.

Figure 5

Refresh Page

The Refresh page lets you schedule asynchronous jobs to update the source metadata. For guidance to set up a refresh schedule, refer to the article Using the Zoomdata Scheduler .

Charts Page

On the Charts page, you can:

  1. Edit Global Default Settings .
  2. Select the Standard and, if available, Custom chart styles to be used with the data source.
  3. Set default parameters (group, sub-group, colors, sorting, and so on) for each chart style.

Figure 6

Learn more about how to customize a chart .

Click Finish to save your changes. Once your data connection has been established, it is listed under the My Data Sources section of the page.