{subsection: schedd -> condor_q}
condor_q sees the copy of the job ad in the schedd (or quill). $$ references are not expanded, but extra attributes exist in the ad to indicate what the result of expansion would be (used for reconnect if the schedd restarts while the job is running).
+
+{subsection: schedd -> job_router}
+
+job_router follows the schedd's transaction log (job_queue.log) and builds its own in-memory copy of the job queue, using the quill libraries.
