Azure Cosmos DB

Getting Started

Use the Azure portal or Azure CLI to create a Cosmos DB account with Cassandra API enabled.

1. Sign in to the Azure portal.
2. Click **Create a resource** → **Databases** → **Azure Cosmos DB**.
3. In the **API** dropdown, select **Cassandra**.
4. Fill in the required fields (Resource Group, Account Name, Region).
5. Click **Review + create**, then **Create**.

az group create --name MyResourceGroup --location eastus
az cosmosdb create \
    --name MyCassandraAccount \
    --resource-group MyResourceGroup \
    --kind GlobalDocumentDB \
    --capabilities EnableCassandra

Sample CQL Queries

Connect using the Cassandra driver of your choice. Below is a Java example using the DataStax driver.

import com.datastax.oss.driver.api.core.CqlSession;
import java.net.InetSocketAddress;

public class CosmosCassandraDemo {
    public static void main(String[] args) {
        try (CqlSession session = CqlSession.builder()
                .addContactPoint(new InetSocketAddress(".documents.azure.com", 10350))
                .withAuthCredentials("", "")
                .withLocalDatacenter("datacenter1")
                .build()) {

            session.execute("CREATE KEYSPACE IF NOT EXISTS demo WITH replication = {'class':'SimpleStrategy','replication_factor':1}");
            session.execute("CREATE TABLE IF NOT EXISTS demo.users (id uuid PRIMARY KEY, name text, age int)");
            session.execute("INSERT INTO demo.users (id, name, age) VALUES (uuid(), 'Alice', 30)");
            session.execute("SELECT * FROM demo.users").forEach(row -> {
                System.out.println(row.getUuid("id") + " | " + row.getString("name") + " | " + row.getInt("age"));
            });
        }
    }
}

Key Concepts

• Keyspaces & Tables: Direct equivalents to Cosmos DB containers.
• Throughput: Provisioned RU/s applies to the entire account; you can also use autoscale.
• Consistency Levels: Strong, Bounded Staleness, Session, Consistent Prefix, and Eventual are supported.
• Indexes: Primary key and secondary indexes work as in Cassandra.
• Security: TLS, IP firewall, and Azure AD integration available.

Resources

• Cassandra API Documentation
• Java Quickstart
• Using the Cassandra Driver
• Performance Best Practices