It depends on your application and the characteristics of the io. You increased executors by 32x and each executor's throughput dropped by 5x, so it makes sense that latency will drop. On May 19, 2015 9:54 AM, "Dima Dragan" <[email protected]> wrote:
> Hi everyone, > > I have found a strange behavior in topology metrics. > > Let`s say, we have 1 node, 2-core machine. simple Storm topology > Spout A -> Bolt B -> Bolt C > > Bolt B splits message on 320 parts and emits (shuffle grouping) each to > Bolt C. Also Bolts B and C make some read/write operations to db. > > Input flow is continuous and static. > > Based on logic, setting up a more higher number of executors for Bolt C > than number of cores should be useless (the bigger part of threads will be > sleeping). > It is confirmed by increasing execute and process latency. > > But I noticed that complete latency has started to decrease. And I do not > understand why. > > For example, stats for bolt C: > > ExecutorsProcess latency (ms)Complete latency (ms)25.599897.27646.3526.364 > 28.432345.454 > > Is it side effect of IO bound tasks? > > Thanks in advance. > > -- > Best regards, > Dmytro Dragan > > >
