The operation of RAGFlow depends on four services:
- **Elasticsearch** (default) or [Infinity](https://github.com/infiniflow/infinity) as the document engine
- **MySQL**
- **Redis**
- **MinIO** for object storage
If an exception or error occurs related to any of the above services, such as `Exception: Can't connect to ES cluster`, refer to this document to check their health status.
You can also click you avatar in the top right corner of the page **>** System to view the visualized health status of RAGFlow's core services. The following screenshot shows that all services are 'green' (running healthily). The task executor displays the *cumulative* number of completed and failed document parsing tasks from the past 30 minutes:
Services with a yellow or red light are not running properly. The following is a screenshot of the system page after running `docker stop ragflow-es-10`: