private static void disableSleeping() {
    HeartbeatHRegion.sleepBetweenRows = false;
    HeartbeatHRegion.sleepBetweenColumnFamilies = false;
  }
Disable the sleeping mechanism server side.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestScannerHeartbeatMessages.java