Hi, I am trying to make sense of number of threads seen in JConsole. It seems like a very high number of threads are launched per bolt thread.
*Experiment 1* topology.workers.val=16 spout.parallelism.val=1 bolt1.parallelism.val=900 bolt2.parallelism.val=160 observation: Threads seen per node in jconsole = 1200 Bolt threads per node = (900 + 160)/16 = 66 Threads per bolt = 1200/66 = 18 *Experiment 2* topology.workers.val=16 spout.parallelism.val=1 bolt1.parallelism.val=16 bolt2.parallelism.val=16 observation: Threads seen per node in jconsole = 61 Bolt threads per node = (16+16)/16 = 2 Threads per bolt = 61/2 = 30 There are no other topologies running in my cluster. There are no other spouts/bolts running in my cluster except the ones mentioned above. I am running only one worker process per machine. So the question is how many threads per bolt are launched by storm? I am not interested in the exact number, but concerned about the high number of extra threads (18+ thread) for running a single bolt. Can we limit or optimize it somehow? Or if all of them are required, it would be good to document them somewhere. Thanks SG
