Apache Cassandra Operator Sample

Contents

About This Sample
Importing This Sample into StreamBase Studio
Running This Sample in StreamBase Studio
This Sample's Files
Sample Location

About This Sample

This topic describes how to run the Spotfire Streaming for Apache Cassandra operator sample application, which illustrates how to use the operators with a Cassandra database cluster.

For more information on this operator, see Using the Apache Cassandra Operators.

This sample includes a number of Cassandra operators, which by default connect to a Cassandra cluster named Test Cluster, and which is assumed to already be running on localhost. This sample also includes a table called myks.users. Once connected, use the sample to read and write to the table using the various operators.

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

  • From the top-level menu, select File>Import Samples and Community Content.

  • Enter cass to narrow the list of options.

  • Select Apache Cassandra Operators from the Large Data Storage and Analysis category.

  • Click Import Now.

StreamBase Studio creates a single project for the Cassandra Operator samples.

Running This Sample in StreamBase Studio

  1. In the Project Explorer view, open the sample you just loaded.

    If you see red marks on a project folder, wait a moment for the project to load its features.

    If the red marks do not resolve themselves after a minute, select the project, right-click, and select Maven>Update Project from the context menu.

  2. Open the src/main/eventflow/packageName folder.

  3. Open the cassandra.sbapp file and click the Run button. This opens the SB Test/Debug perspective and starts the module.

  4. In the Manual Input view, select the QueryIn input stream.

  5. Enter the following values:

    • query: CREATE KEYSPACE myks WITH replication = {'class': 'SimpleStrategy', 'replication_factor' : 1}

    Click Send Data (which triggers the tuple to be sent to the Cassandra cluster as the specified query).

  6. Again in the QueryIn stream, enter the following values and click Send Data to create the table:

    • query: CREATE TABLE myks.users (user_id int PRIMARY KEY, balance double, fname text, lname text, memberSince timestamp)

  7. In the Manual Input view, select the InsertIn input stream.

  8. Enter the following values:

    • user_id: 1

    • balance: 1000.0

    • fname: John

    • lname: Doe

    • membersince: 2001-01-01

    Click Send Data to add the row to the table, and observe that the InsertOut output stream received a tuple indicating that the operation has succeeded.

  9. You may similarly Delete rows and issue SELECT queries using the DeleteIn and SelectIn input streams respectively.

  10. When done, press F9 or click the Terminate EventFlow Fragment button.

This Sample's Files

This sample contains the following files:

cassandra.sbapp

Sample EventFlow application.

Cassandra.conf

Used to configure the Cassandra cluster.

Sample Location

When you load the sample into StreamBase® Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

Important

Load this sample in StreamBase® Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids permission problems. The default workspace location for this sample is: 

studio-workspace/sample_cassandra

See Default Installation Directories for the default location of studio-workspace on your system.