They'll be able to run concurrently and share workers / data. Take a look at http://spark.apache.org/docs/latest/job-scheduling.html <http://spark.apache.org/docs/latest/job-scheduling.html> for how scheduling happens across multiple running jobs in the same SparkContext.
Matei > On Jan 17, 2016, at 8:06 AM, Koert Kuipers <ko...@tresata.com> wrote: > > Same rdd means same sparkcontext means same workers > > Cache/persist the rdd to avoid repeated jobs > > On Jan 17, 2016 5:21 AM, "Mennour Rostom" <mennou...@gmail.com > <mailto:mennou...@gmail.com>> wrote: > 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 > <mailto: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 > <mailto: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 > <mailto: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 >> <mailto: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 >> <mailto:jcove...@gmail.com>> wrote: >> Threads >> >> >> El viernes, 15 de enero de 2016, Kira <mennou...@gmail.com >> <mailto: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 >> >> <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 <> >> >> > > > >
