Self-Hosted Apache Cassandra

sudo apt update && sudo apt upgrade -y

sudo apt install -y openjdk-11-jdk

# Verify installation
java -version

echo 'JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64"' | sudo tee -a /etc/environment
source /etc/environment
echo $JAVA_HOME

# Increase file descriptor limits
echo 'cassandra - nofile 100000' | sudo tee -a /etc/security/limits.conf
echo 'cassandra - memlock unlimited' | sudo tee -a /etc/security/limits.conf
echo 'cassandra - nproc 32768' | sudo tee -a /etc/security/limits.conf
echo 'cassandra - as unlimited' | sudo tee -a /etc/security/limits.conf

# Disable swap (important for Cassandra)
sudo swapoff -a
# Comment out swap line in /etc/fstab to persist after reboot

sudo nano /etc/cassandra/cassandra.yaml

cluster_name: 'RamNodeDev'
num_tokens: 256
listen_address: localhost
rpc_address: localhost
seed_provider:
  - class_name: org.apache.cassandra.locator.SimpleSeedProvider
    parameters:
      - seeds: "127.0.0.1:7000"

sudo nano /etc/cassandra/jvm.options

# For 8GB RAM VPS:
-Xms2G
-Xmx2G

sudo systemctl restart cassandra

# Wait for startup, then verify
sleep 30 && nodetool status

authenticator: PasswordAuthenticator
authorizer: CassandraAuthorizer

# Restart Cassandra after config change
sudo systemctl restart cassandra

# Log in with default credentials
cqlsh -u cassandra -p cassandra

# Create new superuser
CREATE ROLE admin WITH PASSWORD = 'YourSecurePassword' AND SUPERUSER = true AND LOGIN = true;

# Exit and log in as new user
EXIT;
cqlsh -u admin -p 'YourSecurePassword'

# Disable default cassandra user
ALTER ROLE cassandra WITH PASSWORD = 'RandomLongString' AND SUPERUSER = false;

# Generate keystore
keytool -genkeypair -keyalg RSA -alias cassandra \
  -keystore /etc/cassandra/conf/.keystore \
  -storepass cassandra -keypass cassandra \
  -dname "CN=cassandra, OU=RamNode, O=RamNode, L=City, ST=State, C=US" \
  -validity 365

# Export certificate
keytool -export -alias cassandra -file cassandra.cer \
  -keystore /etc/cassandra/conf/.keystore -storepass cassandra

# Import to truststore
keytool -import -alias cassandra -file cassandra.cer \
  -keystore /etc/cassandra/conf/.truststore -storepass cassandra -noprompt

client_encryption_options:
  enabled: true
  optional: false
  keystore: /etc/cassandra/conf/.keystore
  keystore_password: cassandra
  require_client_auth: false

# CQL native transport (client connections)
sudo ufw allow from YOUR_APP_IP to any port 9042

# Inter-node communication (for clusters)
sudo ufw allow from CLUSTER_SUBNET to any port 7000
sudo ufw allow from CLUSTER_SUBNET to any port 7001

# JMX monitoring (restrict to localhost or monitoring server)
sudo ufw allow from 127.0.0.1 to any port 7199

sudo ufw enable

# Local connection
cqlsh localhost

# Authenticated connection
cqlsh localhost -u admin -p 'YourPassword'

# Remote connection
cqlsh YOUR_VPS_IP 9042 -u admin -p 'YourPassword'

-- Single node development
CREATE KEYSPACE myapp WITH replication = {
  'class': 'SimpleStrategy',
  'replication_factor': 1
};

-- Production (multi-datacenter)
CREATE KEYSPACE myapp WITH replication = {
  'class': 'NetworkTopologyStrategy',
  'dc1': 3,
  'dc2': 2
};

USE myapp;

CREATE TABLE users (
  user_id UUID PRIMARY KEY,
  email TEXT,
  username TEXT,
  created_at TIMESTAMP
);

-- Table with clustering columns for time-series data
CREATE TABLE events (
  user_id UUID,
  event_time TIMESTAMP,
  event_type TEXT,
  event_data TEXT,
  PRIMARY KEY (user_id, event_time)
) WITH CLUSTERING ORDER BY (event_time DESC);

-- Insert data
INSERT INTO users (user_id, email, username, created_at)
VALUES (uuid(), 'user@example.com', 'johndoe', toTimestamp(now()));

-- Query data
SELECT * FROM users WHERE user_id = <uuid>;

-- Update data
UPDATE users SET email = 'newemail@example.com' WHERE user_id = <uuid>;

-- Delete data
DELETE FROM users WHERE user_id = <uuid>;

sudo tail -f /var/log/cassandra/system.log

# Create snapshot
nodetool snapshot -t backup_$(date +%Y%m%d)

# Snapshots are stored in:
# /var/lib/cassandra/data/<keyspace>/<table>/snapshots/<snapshot_name>

# Copy snapshots to backup location
sudo rsync -av /var/lib/cassandra/data/*/snapshots/backup_* /backup/cassandra/

# Stop Cassandra
sudo systemctl stop cassandra

# Clear existing data (if needed)
sudo rm -rf /var/lib/cassandra/data/<keyspace>/<table>/*

# Copy snapshot data
sudo cp -r /backup/cassandra/<snapshot>/* /var/lib/cassandra/data/<keyspace>/<table>/

# Fix ownership
sudo chown -R cassandra:cassandra /var/lib/cassandra/data/

# Start Cassandra
sudo systemctl start cassandra

# Refresh sstables
nodetool refresh <keyspace> <table>

#!/bin/bash
# /usr/local/bin/cassandra-backup.sh

BACKUP_DIR="/backup/cassandra"
DATE=$(date +%Y%m%d_%H%M%S)
RETENTION_DAYS=7

# Create snapshot
nodetool snapshot -t "backup_$DATE"

# Copy snapshots
mkdir -p "$BACKUP_DIR/$DATE"
find /var/lib/cassandra/data -path "*/snapshots/backup_$DATE" -exec cp -r {} "$BACKUP_DIR/$DATE/" \;

# Clear snapshot from Cassandra
nodetool clearsnapshot -t "backup_$DATE"

# Remove old backups
find $BACKUP_DIR -maxdepth 1 -type d -mtime +$RETENTION_DAYS -exec rm -rf {} \;

echo "Backup completed: $BACKUP_DIR/$DATE"

# Make executable
chmod +x /usr/local/bin/cassandra-backup.sh

# Add to crontab (daily at 2 AM)
0 2 * * * /usr/local/bin/cassandra-backup.sh >> /var/log/cassandra-backup.log 2>&1