How much pending tuple in queue to next Bolt ? How i am see from code if next Bolt slower than current Bolt ?

[Vadim Smirnov]

 I am have topology Spout1->Bolt1->Bolt2. Sometimes Spout1 produce up to 1000 
tuple/sec, Bolt1 can execute it, but Bolt 2 can only 700 tuple/sec.
Some tuple very valuable, other not. We upgrade topology to: 
Spout1->Bolt1->BoltPriorityBuffer->Bolt2. BoltPriorityBuffer contains 
PriorityQueue and can drop valueless tuple if queue to Bolt2 bloated.

Here question: How i am can see what queue to Bolt2 bloated ? Queue size or may 
be TOPOLOGY_MAX_SPOUT_PENDING event ?

-- 
Vadim Smirnov