about guaranteed message processing

[hjh]

Hi everyone,
    I am confused about reliability API of storm. It seems that 
guaranteed message processing is only for spout. What if I need to 
guarantee message being processed in a subset of bolts? For example, 
bolt A, B, C are connected and tuples are processed from A to B and to 
C, what should I do if I want tuples passed through these three bolts 
being processed fully? I mean once a tuple is passed to A then I should 
make sure that this tuple is processed in B and C but after that I do 
not care whether it is lost or not? Thank you very much!!

Best wishes!!