Command
curl -X GET 'http://localhost:9200/_cluster/health?pretty'Explanation
Retrieves the health status of the entire Elasticsearch cluster. It indicates whether the cluster is operational and if all primary and replica shards are allocated properly.
Common Use Cases
- •Monitoring cluster status and stability
- •Diagnosing shard allocation issues
- •Integrating health checks into alerting systems
Best Practices
- ✓Regularly check cluster health in production environments
- ✓Integrate with monitoring tools such as Kibana or Prometheus
Common Mistakes to Avoid
- ⚠Forgetting to include `?pretty` for readable output
- ⚠Not specifying `level=shards` when detailed shard information is required
Troubleshooting
Problem: Cluster shows 'red' status
Solution: Check unassigned shards with `_cat/shards` and reallocate missing indices.
Problem: Timeouts during health check
Solution: Increase cluster availability or verify node connectivity.
Examples
Cluster health with shard details
curl -X GET 'http://localhost:9200/_cluster/health?level=shards&pretty'