There are three Merger statistics that can be used to better understand how the data flow through the Merger system is proceeding.

Two are from the Link task and one is from the Merger.They are all "No data buffers avaliable" with #1, #2, #3 at the end.

#1: This is incremented when the Link task has a data item to put in the queue for the Merge process but there is no room.

#2: This is incremented when the Link task has found no room in the queue for the Merge process ( #1 ) , waited , tried again and failed. 

#3: This the other end of the queue. When the Merge task requests a data item from a Link task queue and there is nothing available.