Hi Bernard and Kurt, Chaining affects how subtasks operate within slots. Resource groups segregate subtasks into different slots.
https://ci.apache.org/projects/flink/flink-docs-release-1.2/concepts/runtime.html#task-slots-and-resources https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/datastream_api.html#task-chaining-and-resource-groups https://ci.apache.org/projects/flink/flink-docs-release-1.2/setup/config.html#configuring-taskmanager-processing-slots Only a subset of operators can be chained. https://github.com/apache/flink/blob/master/flink-runtime/src/main/java/org/apache/flink/runtime/operators/DriverStrategy.java Greg On Sat, Feb 11, 2017 at 3:25 AM, Kurt Young <ykt...@gmail.com> wrote: > Hi, > > The first answer is "yes", 3 unchained operator will use at least 3 slots, > except if these 3 operators are blocking operators and you are running a > batch job, the operators will use the same slot one after another. > > Regarding to you second question, if you want to start 3 operators with > parallelism of 1, Flink will chain these operators and execute them on the > same slot. But if you disabled chaining, they do need 3 slots. > > > > Best, > Kurt > > On Sat, Feb 11, 2017 at 2:35 AM, bwong247 <bw...@247-inc.com> wrote: > >> Hi Kurt, >> >> Thanks for the reply. >> >> Does this mean that if my job has 3 operators (not chained), it will use >> at >> least 3 slots? I thought parallelism was task based. You can define it >> at >> an operator level, but that only means that the tasks for that operator >> are >> distributed across that many slots. Shouldn't I be able to start the 3 >> operator job with a parallelism of 1 where all the operators run on the >> same >> single slot? >> >> Regards, >> Bernard >> >> >> >> -- >> View this message in context: http://apache-flink-user-maili >> ng-list-archive.2336050.n4.nabble.com/parallelism-and-slo >> ts-allocated-tp11534p11578.html >> Sent from the Apache Flink User Mailing List archive. mailing list >> archive at Nabble.com. >> > >
