Many thanks , but how and when can i decide that this number is perfect form me or not ?
On Mon, Jan 23, 2017 at 1:27 PM, Arun Mahadevan <[email protected]> wrote: > > builder.setBolt("MyBolt", new MyBolt(), 4).shuffleGrouping("MySpout"); i > found this example but couldn't know why he use number 4 ? > > > > This is the “parallelism hint” (the number of threads) for “MyBolt”. So in > your example there will be 4 threads executing “MyBolt” across the workers > in your cluster and the tuples from “MySpout” would be randomly distributed > across all of the 4 instances of your bolt. > > > > Also see http://storm.apache.org/releases/1.0.1/Understanding- > the-parallelism-of-a-Storm-topology.html > > > > > > > > *From: *sam mohel <[email protected]> > *Reply-To: *"[email protected]" <[email protected]> > *Date: *Monday, January 23, 2017 at 4:47 PM > *To: *"[email protected]" <[email protected]> > *Subject: *Re: simple question about grouping > > > > excuse me , if i have single spout and single bolt and the bolt doing 2 > process so can i do like this > builder.setSpout("MySpout", new mySpout(), 1); > builder.setBolt("MyBolt", new MyBolt(), 4).shuffleGrouping("MySpout"); i > found this example but couldn't know why he use number 4 ? > > > > On Mon, Jan 23, 2017 at 1:13 PM, sam mohel <[email protected]> wrote: > > thanks for replying > > > > On Mon, Jan 23, 2017 at 1:14 PM, Arun Mahadevan <[email protected]> wrote: > > > > Grouping makes sense only when you have more than one task for a bolt. If > your bolt has more than one task, then the grouping will decide how the > tuples from the spout are distributed to the individual tasks of the bolt. > (shuffe = random, fields = keyed on some field and so on). > > > > See http://storm.apache.org/releases/current/Concepts.html > > > > Thanks, > > Arun > > > > > > *From: *sam mohel <[email protected]> > *Reply-To: *"[email protected]" <[email protected]> > *Date: *Monday, January 23, 2017 at 3:09 PM > *To: *"[email protected]" <[email protected]>, " > [email protected]" <[email protected]> > *Subject: *simple question about grouping > > > > i have text file contains data . size of this file is 3.5 MB . My topology > consists of one spout and one bolt so is that possible to make all > processing in one bolt and in this case what is the role of grouping here ? > > Thanks in advance > > > > >
