The DQM process is killed / crashed by the Operating System while submitting many jobs and running out of Memory (RAM or Swap)
System running out of memory / pagefile due to the load on the server
Release : 6.x
Component : DOLLAR UNIVERSE
In order to workaround the issue, restart manually DQM once it goes offline.
In order to fix the issue, please increase the memory and virtual memory ( Swap or pagefile ) of the server to avoid this from occurring.
Additionally, I would reduce the number of parallel jobs that can be launched simultaneously on the same server.