java - How to measure latency and throughput in a Storm topology -

i'm learning storm example exclamationtopology. want measure latency (the time takes add !!! word) of bolt , throughput (say, how many words pass through bolt per second).

from here, can count number of words , how many times bolt executed:

_countmetric = new countmetric(); _wordcountmetric = new multicountmetric();   context.registermetric("execute_count", _countmetric, 5); context.registermetric("word_count", _wordcountmetric, 60); 

i know storm ui gives process latency , execute latency , post gives explanation of are.

however, want log latency of every execution of each bolt, , use information along word_count calculate throughput.

how can use storm metrics accomplish this?