In addition to Matthias's opinion, it's true that inter-process communication cost is high, since it also skips serialization / deserialization when destination is same process. And having less workers reduce ZK load.
But you need to configure more heap memory to each worker when using less workers, and without proper GC tuning it may incur long STW. Best, Jungtaek Lim (HeartSaVioR) 2015년 8월 7일 금요일, Matthias J. Sax<[email protected]>님이 작성한 메시지: > IMHO, it's a question about fault-tolerance. > > If you have a single worker per node per topology, the impact in failure > case (ie, rack going down) on a topology is low. Of course, all > topologies using this failure rack are effected. > > If you use multiple workers for a single topology on the same > supervisor, the impact is high. In fact, if you use a single supervisor, > the whole topology goes down. On the other hand, it might effect less > topologies... > > Thus, it's a tradeoff you need to consider by yourself. > > > -Matthias > > On 08/07/2015 09:24 AM, Denis DEBARBIEUX wrote: > > Hi, > > > > I am always doing like that. I will be interested if this invariant had > > been updated > > > > Denis > > > > Le 07/08/2015 08:47, 이승진 a écrit : > >> > >> I read articles about this before suggesting this. > >> > >> > >> > >> And I tried to run a topology in 2 workers in a same node, but > >> performance was bad at that moment, even though resource usage was not > >> that high. > >> > >> (Sorry that I cannot mention exact metrics since I didn't keep it) > >> > >> > >> > >> I remember that this is because inter process communication is > expensive. > >> > >> > >> > >> This recommendation is still valid and should I use storm that way? > >> > >> > >> > > > > > > > > ------------------------------------------------------------------------ > > Avast logo <https://www.avast.com/antivirus> > > > > L'absence de virus dans ce courrier électronique a été vérifiée par le > > logiciel antivirus Avast. > > www.avast.com <https://www.avast.com/antivirus> > > > > > > -- Name : 임 정택 Blog : http://www.heartsavior.net / http://dev.heartsavior.net Twitter : http://twitter.com/heartsavior LinkedIn : http://www.linkedin.com/in/heartsavior
