Internal users
The Elastic Stack includes Elastic's core products such as Elasticsearch, Kibana, Logstash, and Beats. Availability This functionality is generally available and ready for production usage. Unless stated otherwise on the page, this functionality is available when your Elastic Stack is deployed on Elastic Cloud Hosted, Elastic Cloud Enterprise, Elastic Cloud on Kubernetes, and self-managed environments. This documentation corresponds to the latest patch available for each minor version. If you're not using the latest patch, check the release notes for changes.
Stack
Generally available
These users are designed for internal use by Elasticsearch only. Authenticating with these users is not supported.
The Elastic Stack security features use eight internal users (_system, _xpack, _xpack_security, _async_search, _security_profile, _data_stream_lifecycle, _synonyms and _storage), which are responsible for the operations that take place inside an Elasticsearch cluster.
These users are only used by requests that originate from within the cluster. For this reason, they cannot be used to authenticate against the API and there is no password to manage or reset.
From time-to-time you may find a reference to one of these users inside your logs, including audit logs.