What is the method for restarting an Elasticsearch cluster?

To restart the Elasticsearch cluster, follow these steps:

1. Stop Elasticsearch nodes: Run the ‘bin/elasticsearch stop’ command on each node, or stop the node by stopping the Elasticsearch process.
2. Make sure all nodes have stopped: You can check the status of the nodes by using the command curl -XGET ‘http://localhost:9200/_cat/nodes’. If all nodes are no longer running, you can proceed to the next step.
3. Start Elasticsearch nodes by running the bin/elasticsearch start command on each node, or by starting the Elasticsearch process to initiate the nodes.
4. Check the cluster status by using the command curl -XGET ‘http://localhost:9200/_cluster/health’ to determine if the cluster is up and running, indicated by a green or yellow status.

Please note that before restarting the Elasticsearch cluster, make sure to have backed up all important data and understand the risk of potential data loss that may occur during the restart.