public float getHeapOccupancyPercent() {
    return this.heapOccupancyPercent == Float.MAX_VALUE
      ? HEAP_OCCUPANCY_ERROR_VALUE
      : this.heapOccupancyPercent;
  }
Returns heap occupancy percentage, 0 &lt;= n &lt;= 1. or -0.0 for error asking JVM
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HeapMemoryManager.java