Day 11: Cassandra Lab Practice – Backup, Restore & Monitoring

✅ Day 11: Backups, Snapshots, and Monitoring in Cassandra

🎯 Objective:

Learn how to take backups, restore data using snapshots, and monitor a Cassandra node using nodetool.

---

📦 1. Backups via Snapshots

➤ What is a Snapshot?

A snapshot is a backup of the SSTable files (on-disk data) at a certain point in time.

➤ Take a Snapshot:

nodetool snapshot test_lab

📂 Snapshot files will be saved under:

/var/lib/cassandra/data/<keyspace>/<table>/snapshots/

---

♻️ 2. Restore from Snapshot

➤ Steps:

1. Stop Cassandra:

sudo systemctl stop cassandra

1. Copy snapshot files into the main table folder:

cp -R /var/lib/cassandra/data/test_lab/employee/snapshots/<snapshot_name>/* \
      /var/lib/cassandra/data/test_lab/employee/

1. Clear commit logs (optional for full restore)
2. Restart Cassandra:

sudo systemctl start cassandra

1. Run SELECT * to verify data is back.

---

🔍 3. Monitoring with nodetool

➤ Status of the Node:

nodetool status

➤ Disk Usage:

nodetool cfstats

➤ View running compactions:

nodetool compactionstats

➤ View pending tasks and activity:

nodetool tpstats

---

🧪 4. Optional: Enable Logging & Metrics

• Cassandra logs: /var/log/cassandra/system.log
• Enable JMX for metrics monitoring tools like Prometheus, Grafana

---

🧪 Day 11 Lab Tasks

1. Take a snapshot of the test_lab keyspace
2. Verify files in the snapshot directory
3. Simulate restore (copy snapshot to live folder)

4. Run and interpret nodetool commands:

   • status, cfstats, tpstats, compactionstats

---

✅ Final Checklist

Task	Done
Took snapshot of a keyspace	✅
Understood snapshot directory structure	✅
Restored data using snapshot files	✅
Ran nodetool monitoring commands	✅

---

🏁 Congratulations! 🎉

You've completed 11 Days of Cassandra Lab Practice with:

• Setup & Basic Operations
• Data Modeling
• Advanced Querying
• Backup & Monitoring