This SO answer seems to answer your question: http://stackoverflow.com/a/17454586/234901
On Mon, Feb 17, 2014 at 7:30 PM, Abhishek Bhattacharjee < [email protected]> wrote: > If you see practically number of workers should always be less than or > equal to the number of tasks. This is not only valid for Comp sci but for > any field. If we have more no. of workers than tasks available then we are > just wasting our resources. That is we are not using our resources > optimally. > So in most cases there should at least be one task or more running on an > executor. > Now, consider an executor which normalizes a sentence into words, now when > sentence arrives the executor normalizes that sentence after it is finished > it is ready to receive another tuple. > With storm there could be several executors doing the same job with > different sentences simultaneously but that doesn't mean we have to have as > many no. of executors as there are sentences. I hope this makes sense. > > > On Mon, Feb 17, 2014 at 11:11 PM, Simon Cooper < > [email protected]> wrote: > >> I've been looking at the parallelism of a storm topology. In what >> situations is it useful to have more than one task running on the same >> executor? An executor is a thread, so if there's several tasks on that >> executor only one task can run at a time. So why would you want more than >> one task on the same thread, if only one can run at once? >> >> >> >> SimonC >> > > > > -- > *Abhishek Bhattacharjee* > *Pune Institute of Computer Technology* >
