More specifically, the bottom of this page explains what the numbers mean in terms of tasks and executors: http://nrecursions.blogspot.in/2016/05/more-concepts-of-apache-storm-you-need.html
On Mon, Jan 23, 2017 at 5:28 PM, sam mohel <[email protected]> wrote: > really thanks for your help > > On Mon, Jan 23, 2017 at 1:59 PM, Arun Mahadevan <[email protected]> wrote: > >> There is no magic number, it depends on the specific problem you are >> trying to solve. You start with some reasonable value for the parallelism >> and tune it based on your requirements. You could also start with a higher >> number of “tasks” than the parallelism and then you can rebalance your >> topology and adjust parallelism on the fly to scale up or down. >> >> >> >> See the slides from Taylor’s “Scaling Storm” presentation, you might find >> it useful - http://www.slideshare.net/ptgoetz/scaling-apache-storm-strat >> a-hadoopworld-2014 >> >> >> >> >> >> *From: *sam mohel <[email protected]> >> *Reply-To: *"[email protected]" <[email protected]> >> *Date: *Monday, January 23, 2017 at 4:58 PM >> >> *To: *"[email protected]" <[email protected]> >> *Subject: *Re: simple question about grouping >> >> >> >> 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 >> >> >> >> >> >> >> > > -- Regards, Navin
