An executed graph can occupy one of the following states.
Job execution request has been registered and persisted. This status lasts only for a short interval.
Job initialization process is almost done.
Job is running.
Used only by the engine as a component status.
The job finished without a failure.
A failure occurred during data processing or during initialization process.
The job has been aborted or killed.
May occur when the job execution exceeds a specified limit, but the TIMEOUT status is never visible in the execution history. Time-outed job may be aborted, thus the status changes from RUNNING to ABORTED.
When the server detects inconsistency of the job status, it is set as UNKNOWN. For example, when the server starts-up and there are RUNNING jobs in the database, which is impossible since the server has not started yet.