Query Impala Data as a SQL Server Database in Node.js

You can use CData Connect AI to query Impala data through a SQL Server interface. Follow the procedure below to create a virtual database for Impala in Connect AI and start querying using Node.js.

CData Connect AI provides a pure MySQL, cloud-to-cloud interface for Impala, allowing you to easily query live Impala data in Node.js — without replicating the data to a natively supported database. As you query data in Node.js, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc) directly to Impala, leveraging server-side processing to quickly return Impala data.

Configure Impala Connectivity for NodeJS

Connectivity to Impala from NodeJS is made possible through CData Connect AI. To work with Impala data from NodeJS, we start by creating and configuring a Impala connection.

1. Log into Connect AI, click Sources, and then click Add Connection
👁 Adding a Connection

2. Select "Impala" from the Add Connection panel
👁 Selecting a data source

3. Enter the necessary authentication properties to connect to Impala.

   In order to connect to Apache Impala, set the Server, Port, and ProtocolVersion. You may optionally specify a default Database. To connect using alternative methods, such as NOSASL, LDAP, or Kerberos, refer to the online Help documentation.

   👁 Configuring a connection (Salesforce is shown)
   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Impala Connection page and update the User-based permissions. 👁 Updating permissions
   

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create. 👁 Creating a new PAT
   
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

With the connection configured and a PAT generated, you are ready to connect to Impala data from Node.js.

Query Impala from Node.js

The following example shows how to define a connection and execute queries to Impala with the SQL Server module. You will need the following information:

• server: tds.cdata.com
• port: 14333
• user: a Connect AI user (e.g. [email protected])
• password: the PAT for the above user
• database: The connection you configured for Impala (ApacheImpala1)

Connect to Impala data and start executing queries with the code below:

var sql = require('mssql')
var config = {
	server: 'tds.cdata.com',
	port: 14333, 
	user: '[email protected]', //update me
	password: 'CONNECT_USER_PAT', //update me	
	options: {
		encrypt: true,
		database: 'ApacheImpala1'
	}
}

sql.connect(config, err => { 
 if(err){
 throw err ;
 }
 new sql.Request().query('SELECT * FROM Customers', (err, result) => {
 console.dir(result)
 })
 
});

sql.on('error', err => {
 console.log("SQL Error: " ,err);
})