{endverbatim}
Note that this does not _guarantee_ that HTCondor will only start the job once. The =NumJobStarts= job attribute is updated shortly after the job starts running. Various types of failures can result in the job starting without this attribute being updated (e.g. network failure between submit and execute machine). By setting SHADOW_LAZY_QUEUE_UPDATE=false, the window of time between the job starting and the update of =NumJobStarts= can be decreased, but this still does not provide a guarantee that the job will never be started more than once. This policy is therefore to start the job at least once, and, with best effort but no strong guarantee, not more than once. As usual, HTCondor _does_ provide a strong guarantee that the job is never running more than once at the same time.
+
+Instead of NumJobStarts, you can flag off of several over attributes that are incremented when a job starts up:
+
+*: NumShadowStarts - Incremented when the condor_shadow starts, but before the job has started. Guarantees that a job will run at most once, but it a problem occurs between the shadow starting and the job starting, the job will never run.
+*: NumJobMatches -
+*: JobRunCount -
