Cassandra Operations: Backup, Repair, and Cluster Management

# On new node: Install Cassandra with same version
# Configure cassandra.yaml

# Start Cassandra on new node
sudo service cassandra start

# From existing node: Join to cluster
nodetool join -h <new_node_ip>

# Or if using virtual nodes, simply start Cassandra
# It will automatically join cluster

# Check node status
nodetool status

# Decommission a node (graceful)
nodetool decommission

# Remove a node forcefully (if crashed)
nodetool assassinate <node_ip>

# Repair specific keyspace
nodetool repair mykeyspace

# Incremental repair (Cassandra 3.0+)
nodetool repair -inc mykeyspace

# Parallel repair
nodetool repair -pr mykeyspace

# Take snapshot of a table
nodetool snapshot -t my_snapshot mykeyspace mytable

# Take snapshot of entire keyspace
nodetool snapshot -t full_backup mykeyspace

# Clear snapshot
nodetool clearsnapshot -t my_snapshot

# 1. Truncate table
cqlsh -e "TRUNCATE mykeyspace.mytable;"

# 2. Stop Cassandra
sudo service cassandra stop

# 3. Copy snapshot files
cp /backup/mykeyspace/mytable/*/snapshots/my_snapshot/* \
   /var/lib/cassandra/data/mykeyspace/mytable-*/

# 4. Start Cassandra
sudo service cassandra start

# 5. Run repair
nodetool repair mykeyspace mytable

# Check node status
nodetool status

# Table statistics
nodetool tablestats mykeyspace.mytable

# Column family stats
nodetool cfstats mykeyspace.mytable

# Compaction stats
nodetool compactionstats

# Get thread pool stats
nodetool tpstats

# Proxy histograms
nodetool proxyhistograms

# View log entries
tail -f /var/log/cassandra/system.log

-- Create superuser
CREATE ROLE admin WITH SUPERUSER = true AND LOGIN = true 
PASSWORD = 'secure_password';

-- Create application user
CREATE ROLE appuser WITH LOGIN = true PASSWORD = 'app_password';

-- Grant permissions
GRANT ALL ON KEYSPACE myapp TO appuser;

-- Default for write-heavy workloads
CREATE TABLE mykeyspace.mytable (
    id UUID PRIMARY KEY,
    data TEXT
) WITH compaction = {
    'class': 'SizeTieredCompactionStrategy',
    'min_threshold': 4,
    'max_threshold': 32
};

-- Better for read-heavy workloads
CREATE TABLE mykeyspace.mytable (
    id UUID PRIMARY KEY,
    data TEXT
) WITH compaction = {
    'class': 'LeveledCompactionStrategy',
    'sstable_size_in_mb': 160
};

-- Best for time-series data
CREATE TABLE mykeyspace.timeseries (
    id UUID,
    timestamp TIMESTAMP,
    data TEXT,
    PRIMARY KEY (id, timestamp)
) WITH compaction = {
    'class': 'TimeWindowCompactionStrategy',
    'compaction_window_unit': 'DAYS',
    'compaction_window_size': 1
};