Command
curl -X POST 'http://localhost:9200/_aliases?pretty' -H 'Content-Type: application/json' -d '{"actions":[{"add":{"index":"my_index","alias":"current"}}]}'Explanation
Aliases act as virtual index names. Useful for switching indices transparently without affecting applications.
Common Use Cases
- •Zero-downtime reindexing
- •Routing search/indexing operations to multiple indices
- •Rolling index updates
Best Practices
- ✓Always use aliases in applications instead of direct index names
- ✓Use write and read aliases for safe migrations
Common Mistakes to Avoid
- ⚠Using aliases as real index names in admin operations
- ⚠Not removing old index alias references after switching
Troubleshooting
Problem: Alias already exists
Solution: Use 'remove' action before adding the new alias.
Problem: Conflicting write aliases
Solution: Ensure only ONE write index per alias.
Examples
Add alias to users index
curl -X POST 'http://localhost:9200/_aliases?pretty' -H 'Content-Type: application/json' -d '{"actions":[{"add":{"index":"users","alias":"active_users"}}]}'