title: running into an issue when running query on Impala
body: <p>I've been running into the following issue when running basic queries on Impala (For example: <code>select * from table limit 100</code>)  recently. I did some online research but have not found a fix for this. any insights on how I could fix this? I use HUE for querying.</p>
  <blockquote>
  <p>ExecQueryFInstances rpc query_id=5d4f8d25428xxxx:813cfbd30000xxxx
  failed: Failed to get minimum memory reservation of 8.00 MB on daemon
  ser1830.xxxx.com:22000 for query xxxxxxxxx:813cfbd30xxxxxxxxx
  due to following error: Failed to increase reservation by 8.00 MB
  because it would exceed the applicable reservation limit for the
  &quot;Process&quot; ReservationTracker: reservation_limit=68.49 GB
  reservation=68.49 GB used_reservation=0 child_reservations=68.49 GB
  The top 5 queries that allocated memory under this tracker are:
  Query(5240724f8exxxxxx:ab377425000xxxxxx): Reservation=41.81 GB
  ReservationLimit=64.46 GB OtherMemory=133.44 MB Total=41.94 GB
  Peak=42.62 GB Query(394dcbbaf6bxxxxx2f4760000xxxxxx0):
  Reservation=26.68 GB ReservationLimit=64.46 GB OtherMemory=92.94 KB
  Total=26.68 GB Peak=26.68 GB Query(5d4f8d25428xxxxx:813cfbd30000xxxxx):
  Limit=100.00 GB Reservation=0 ReservationLimit=64.46 GB OtherMemory=0
  Total=0 Peak=0 Memory is likely oversubscribed. Reducing query
  concurrency or configuring admission control may help avoid this
  error.</p>
  </blockquote>