The _system_ user is an internal user that's used by Artifactory to run different tasks, such as authentication.
If you're running Artifactory HA, the authentication with other nodes will be performed by the _system_ user.
Another task that can be performed by this user includes cleanup operations. For example, when a policy for cleaning unique tags has been configured (that's based on the maximum unique tags value inside a repository), the old tags will be cleaned up by the _system_ user. Even if you're using cleanup user plugins, such as buildCleanup or artifactCleanup, the cleanup tasks will also be performed by the _system_ user.
Next time you encounter such actions by _system_ user, you may want to check any of the above.
Published: May 16, 2019
Last updated: May 23, 2021