Hi, Thank you all for your answers,
If I correctly understand, actions (in my case foreach) can be run concurrently and simultaneously on the SAME rdd, (which is logical because they are read only object). however, I want to know if the same workers are used for the concurrent analysis ? Thank you 2016-01-15 21:11 GMT+01:00 Jakob Odersky <joder...@gmail.com>: > I stand corrected. How considerable are the benefits though? Will the > scheduler be able to dispatch jobs from both actions simultaneously (or on > a when-workers-become-available basis)? > > On 15 January 2016 at 11:44, Koert Kuipers <ko...@tresata.com> wrote: > >> we run multiple actions on the same (cached) rdd all the time, i guess in >> different threads indeed (its in akka) >> >> On Fri, Jan 15, 2016 at 2:40 PM, Matei Zaharia <matei.zaha...@gmail.com> >> wrote: >> >>> RDDs actually are thread-safe, and quite a few applications use them >>> this way, e.g. the JDBC server. >>> >>> Matei >>> >>> On Jan 15, 2016, at 2:10 PM, Jakob Odersky <joder...@gmail.com> wrote: >>> >>> I don't think RDDs are threadsafe. >>> More fundamentally however, why would you want to run RDD actions in >>> parallel? The idea behind RDDs is to provide you with an abstraction for >>> computing parallel operations on distributed data. Even if you were to call >>> actions from several threads at once, the individual executors of your >>> spark environment would still have to perform operations sequentially. >>> >>> As an alternative, I would suggest to restructure your RDD >>> transformations to compute the required results in one single operation. >>> >>> On 15 January 2016 at 06:18, Jonathan Coveney <jcove...@gmail.com> >>> wrote: >>> >>>> Threads >>>> >>>> >>>> El viernes, 15 de enero de 2016, Kira <mennou...@gmail.com> escribió: >>>> >>>>> Hi, >>>>> >>>>> Can we run *simultaneous* actions on the *same RDD* ?; if yes how can >>>>> this >>>>> be done ? >>>>> >>>>> Thank you, >>>>> Regards >>>>> >>>>> >>>>> >>>>> -- >>>>> View this message in context: >>>>> http://apache-spark-user-list.1001560.n3.nabble.com/simultaneous-actions-tp25977.html >>>>> Sent from the Apache Spark User List mailing list archive at >>>>> Nabble.com <http://nabble.com>. >>>>> >>>>> --------------------------------------------------------------------- >>>>> To unsubscribe, e-mail: user-unsubscr...@spark.apache.org >>>>> For additional commands, e-mail: user-h...@spark.apache.org >>>>> >>>>> >>> >>> >> >
