Using Liquibase with Cassandra on DataStax Astra

DataStax Astra is a multi-cloud DBaaS built on Apache Cassandra. Astra simplifies cloud-native Cassandra application development and reduces deployment time from weeks to minutes. For more information, see DataStax AstraDB Documentation.

Supported versions

• 4.X
• 3.11.X

Verification level

Compatible: Reported to work by the community. May have partially passed Foundational-level testing.

Note: A database's verification level indicates how well it works with different features in Liquibase and across different products, such as Liquibase Community and Liquibase Pro. For more information, see Liquibase Database Tutorials.

Prerequisites

• Install Liquibase.
• Create a Liquibase project folder to store all Liquibase files. You can do this manually or with the init project command.
• Create a new Liquibase properties file or use the liquibase.properties file included in the installation package. For more information, see Specifying Properties in a Connection Profile.

Install drivers

To use Liquibase and Cassandra on DataStax Astra, you need two JAR files: a JDBC driver and the Liquibase Cassandra extension:

1. Download the Simba JDBC driver JAR file and select Simba JDBC Driver for Apache Cassandra from the dropdown menu. Select the default package option unless you need a specific package. The driver downloads as a ZIP file named SimbaCassandraJDBC42-x.x.x.zip.
2. Extract the CassandraJDBCxx.jar file and place it in the liquibase/lib directory.
3. Open the Liquibase properties file and specify the driver, as follows:

driver: com.simba.cassandra.jdbc42.Driver

4. Go to the liquibase-cassandra repository and download the latest released Liquibase extension JAR file: liquibase-cassandra-version.jar.

Place your JAR file(s) in the liquibase/lib directory. Read more: Adding and Updating Liquibase Drivers.

If you use Maven, note that this database does not provide its driver JAR on a public Maven repository, so you must install a local copy and add it as a dependency to your pom.xml file. Read more: Configuring Liquibase Attributes in your Maven POM File.

<dependency>
    <groupId>com.datastax.jdbc</groupId>
    <artifactId>CassandraJDBC42</artifactId>
    <version>4.2</version>
    <scope>system</scope>
    <systemPath>${basedir}/lib/CassandraJDBC42.jar</systemPath>
</dependency>
<dependency>
    <groupId>org.liquibase.ext</groupId>
    <artifactId>liquibase-cassandra</artifactId>
    <version>4.16.1</version>
</dependency>

You need to specify that the scope is system and provide the systemPath in pom.xml. In the example, the ${basedir}/lib is the location of the driver JAR file.

Test your connection

1. Ensure your Cassandra on DataStax Astra database is configured:
   1. Log into your DataStax Astra account. From Dashboard, select the needed database, and then go to the Connect tab. Under Connect using an API, select Java and download the Connect Bundle by following the link in step 1 under Prerequisites.
   2. Once the secure-connect-<dbname>.zip file is fully downloaded, place it in a secure place in your file system.
   3. Unzip the secure-connect-<dbname>.zip file. Open the config.json file in a text editor. We will use the information from the file in the next step.
   4. Clone the cql-proxy repository to set up CQL-Proxy, which is a sidecar that enables unsupported CQL drivers to work with DataStax Astra.
      1. You need your Astra Token and Astra Database ID to use CQL-Proxy.
      2. Follow the steps in the repository to spin up CQL-Proxy using your command prompt. Once successfully running, you should see the following output:
      {"level":"info","ts":1651012815.176512,"caller":"proxy/proxy.go:222","msg":"proxy is listening","address":"[::]:9042"}

2. Specify the database URL in the Liquibase properties file. Liquibase does not parse the URL. You can either specify the full database connection string or specify the URL using your database's standard JDBC format:

   url: jdbc:cassandra://localhost:9042/test;DefaultKeyspace=test;TunableConsistency=6

   Replace test with your own keyspace name.

Tip: To apply a Liquibase Pro key to your project, add the following property to the Liquibase properties file: liquibaseProLicenseKey: <paste code here>

3. Create a text file called changelog (.xml, .sql, .json, or .yaml) in your project directory and add a changeset.
XML example

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
	xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
	xmlns:pro="http://www.liquibase.org/xml/ns/pro"
	xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
		http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
		http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
		http://www.liquibase.org/xml/ns/pro http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd">
    <changeSet id="1" author="Liquibase">
    <createTable tableName="test_table">
           <column name="test_id" type="int">
                 <constraints primaryKey="true"/>
           </column>
           <column name="test_column" type="varchar"/>
    </createTable>
    </changeSet>
</databaseChangeLog>

SQL example

-- liquibase formatted sql

-- changeset liquibase:1
CREATE TABLE test_table (test_id INT, test_column VARCHAR(256), PRIMARY KEY (test_id))

Tip: Formatted SQL changelogs generated from Liquibase versions before 4.2 might cause issues because of the lack of space after a double dash ( -- ). To fix this, add a space after the double dash. For example: -- liquibase formatted sql instead of --liquibase formatted sql and -- changeset myname:create-table instead of --changeset myname:create-table

YAML example

databaseChangeLog:
   - changeSet:
       id: 1
       author: Liquibase
       changes:
       - createTable:
           columns:
           - column:
               name: test_column
               type: INT
               constraints:  
                   primaryKey:  true  
                   nullable:  false  
                   tableName: test_table

JSON example

{ 
  "databaseChangeLog": [
  {
	"changeSet": {
	  "id": "1",
      "author": "Liquibase",
	  "changes": [
	    {
		  "createTable": {
		    "columns": [
			{
			  "column": 
		      {
				"name": "test_column",
				"type": "INT",
				"constraints": 
			  {
				"primaryKey": true,
				"nullable": false
				}
				}
			  }]
			,
			"tableName": "test_table"
		  }
		}]
	  }
	}]
  }

4. Navigate to your project folder in the CLI and run the Liquibase status command to see whether the connection is successful:

liquibase --username=test --password=test --changelog-file=<changelog.xml> status

Note: You can pass arguments in the CLI or keep them in the Liquibase properties file.

5. Inspect the SQL with the update-sql command. Then make changes to your database with the update command.

liquibase --changelog-file=<changelog.xml> update-sql
liquibase --changelog-file=<changelog.xml> update

6. From a database UI tool, ensure that your database contains the test_table you added along with the DATABASECHANGELOG table and DATABASECHANGELOGLOCK table.

Related links

• Get Up and Running with Liquibase and Apache Cassandra
• Liquibase Change Types
• Concepts
• Liquibase Commands
• Workflows