Elasticsearch 7 and Elastic Stack - In Depth and Hands On! - Failover in Action - Part 1

The video tutorial demonstrates how to manage an Elasticsearch cluster by starting nodes, monitoring cluster health, adding nodes, simulating node failures, and recovering from them. It covers using system control commands to manage nodes, checking cluster status with health queries, and observing Elasticsearch's failover capabilities. The tutorial emphasizes the importance of having multiple nodes for redundancy and shows how Elasticsearch dynamically adapts to changes in the cluster.

What command is used to stop the Elasticsearch service?

• sudo bin system control stop Elasticsearch

• sudo bin system control start Elasticsearch

• sudo bin system control status Elasticsearch

• sudo bin system control restart Elasticsearch

Why is it important to have at least three nodes in an Elasticsearch cluster?

• To ensure data redundancy

• To increase storage capacity

• To elect a new master if the current one fails

• To improve search speed

What happens to the cluster status when the original master node is stopped?

• It becomes blue

• It turns yellow

• It remains green

• It turns red

How does the cluster respond to search queries when the master node is down?

• Search queries are redirected

• Search queries are delayed

• Search queries fail

• Search queries continue to be served

What is the first step in recovering a failed node?

• Update the software

• Check the network connection

• Restart the node

• Replace the hard drive

What command is used to start a node back into service?

• sudo bin system control status Elasticsearch

• sudo bin system control restart Elasticsearch

• sudo bin system control start Elasticsearch

• sudo bin system control stop Elasticsearch

What should you do if a node does not spin back up reliably?

• Restart all services

• Reinstall Elasticsearch

• Check the logs

• Increase CPU allocation