Configuring Cassandra

This page covers Cassandra version management and configuration. For a step-by-step walkthrough, see the Tutorial.

Supported Versions

easy-db-lab supports the following Cassandra versions:

Quick Start

# Select Cassandra 5.0
easy-db-lab cassandra use 5.0

# Generate configuration patch
easy-db-lab cassandra write-config

# Apply configuration and start
easy-db-lab cassandra update-config
easy-db-lab cassandra start

# Verify cluster
ssh db0 nodetool status

Version Management

Select a Version

easy-db-lab cassandra use <version>

Examples:

easy-db-lab cassandra use 5.0       # Latest stable
easy-db-lab cassandra use 4.1       # LTS version
easy-db-lab cassandra use trunk     # Development branch

This command:

1. Sets the active Cassandra version on all nodes
2. Downloads current configuration files locally
3. Applies any existing cassandra.patch.yaml

Specify Java Version

easy-db-lab cassandra use 5.0 --java 11

List Available Versions

easy-db-lab ls

Configuration

The Patch File

Cassandra configuration uses a patch file approach. The cassandra.patch.yaml file contains only the settings you want to customize, which are merged with the default cassandra.yaml.

Generate a new patch file:

easy-db-lab cassandra write-config

Options:

• -t, --tokens: Number of tokens (default: 4)

Example patch file:

cluster_name: "my-cluster"
num_tokens: 4
concurrent_reads: 64
concurrent_writes: 64
trickle_fsync: true

Apply Configuration

easy-db-lab cassandra update-config

Options:

• --restart, -r: Restart Cassandra after applying
• --hosts: Filter to specific hosts

Apply and restart in one command:

easy-db-lab cassandra update-config --restart

Download Configuration

Download current configuration files from nodes:

easy-db-lab cassandra download-config

Files are saved to a local directory named after the version (e.g., 5.0/).

Starting and Stopping

# Start on all nodes
easy-db-lab cassandra start

# Stop on all nodes
easy-db-lab cassandra stop

# Restart on all nodes
easy-db-lab cassandra restart

# Target specific hosts
easy-db-lab cassandra start --hosts db0,db1

Cassandra Sidecar

The Apache Cassandra Sidecar is automatically installed and started alongside Cassandra. The sidecar provides:

• REST API for Cassandra operations
• S3 import/restore capabilities
• Streaming data operations
• Metrics collection (Prometheus-compatible)

Sidecar Access

The sidecar runs on port 9043 on each Cassandra node:

# Check sidecar health
curl http://<cassandra-node-ip>:9043/api/v1/__health

Sidecar Management

The sidecar is managed via systemd:

# Check status
ssh db0 sudo systemctl status cassandra-sidecar

# Restart
ssh db0 sudo systemctl restart cassandra-sidecar

Sidecar Configuration

Configuration is located at /etc/cassandra-sidecar/cassandra-sidecar.yaml on each node. Key settings:

• Cassandra connection details
• Data directory paths
• Traffic shaping and throttling
• S3 integration settings

Custom Builds

To run a custom Cassandra build (your own fork, a feature branch, or a prebuilt tarball), add a version entry and rebuild the AMI. easy-db-lab bakes every listed version into the image — there is no separate build-from-path command.

You don't edit the repository's cassandra_versions.yaml. Instead, drop one or more YAML files into your profile's extras directory:

~/.easy-db-lab/profiles/<profile>/cassandra_versions/

(The default profile is default.) At build time these are merged with the built-in versions. Each version must be unique across the built-in list and your extras, or the build fails.

1. Add a version entry

Create e.g. ~/.easy-db-lab/profiles/default/cassandra_versions/my-build.yaml.

Build from a git branch (cloned and compiled with ant during the AMI build):

- version: "my-build"
  java: "11"
  python: "3.10.6"
  url: "https://github.com/myuser/cassandra.git"
  branch: "my-feature-branch"
  ant_flags: "-Duse.jdk11=true"   # optional, passed to ant

Or install a prebuilt tarball:

- version: "my-build"
  java: "11"
  python: "3.10.6"
  url: "https://example.com/apache-cassandra-my-build-bin.tar.gz"

An entry with no url/branch downloads the matching official Apache release.

2. Rebuild the Cassandra AMI

easy-db-lab build-cassandra

3. Select the custom build

easy-db-lab cassandra use my-build

Next Steps

• Tutorial - Complete walkthrough
• Shell Aliases - Convenient shortcuts for Cassandra management