@SuppressWarnings("FutureReturnValueIgnored")
  private boolean internalQueueIncrement(byte[] tableName, byte[] rowKey, byte[] fam, byte[] qual,
    long ammount) {
    int countersMapSize = countersMap.size();

    // Make sure that the number of threads is scaled.
    dynamicallySetCoreSize(countersMapSize);

    totalIncrements.increment();

    FullyQualifiedRow key = new FullyQualifiedRow(tableName, rowKey, fam, qual);

    long currentAmount = ammount;
    // Spin until able to insert the value back without collisions
    while (true) {
      Long value = countersMap.remove(key);
      if (value == null) {
        // There was nothing there, create a new value
        value = currentAmount;
      } else {
        value += currentAmount;
        successfulCoalescings.increment();
      }
      // Try to put the value, only if there was none
      Long oldValue = countersMap.putIfAbsent(key, value);
      if (oldValue == null) {
        // We were able to put it in, we're done
        break;
      }
      // Someone else was able to put a value in, so let's remember our
      // current value (plus what we picked up) and retry to add it in
      currentAmount = value;
    }

    // We limit the size of the queue simply because all we need is a
    // notification that something needs to be incremented. No need
    // for millions of callables that mean the same thing.
    if (pool.getQueue().size() <= 1000) {
      // queue it up
      Callable<Integer> callable = createIncCallable();
      pool.submit(callable);
    }

    return true;
  }
Used to identify a cell that will be incremented.
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift/IncrementCoalescer.java