To which component should the ES application be uploaded?

The correct choice is the search head because the Enterprise Security (ES) application is meant to provide enhanced capabilities for data visualization, analysis, and investigation. The search head is responsible for running searches and executing the various functionalities provided by the ES app, as it is the component that interacts with users and allows them to query the indexed data.

When you upload the ES app to the search head, users gain access to its dashboards, correlations, and workflows, which are designed for security operations. Therefore, it’s essential that the application is made available on the search head for users to effectively leverage its tools and features for incident response, security monitoring, and threat detection.

The other components are not suitable for uploading the ES app for these reasons: the data indexer is primarily responsible for data ingestion and storage, the deployment server manages app distribution across instances but does not host the applications for user access, and the cluster master is involved in managing indexer clustering but does not serve as a point for end-user interaction with applications like ES. Hence, uploading the ES application to the search head is the correct approach for its intended use.