The docs have a good discussion of how acks work: https://storm.apache.org/documentation/Guaranteeing-message-processing.html
On Mon, Feb 23, 2015 at 2:14 PM, Nick R. Katsipoulakis < [email protected]> wrote: > Ok, that makes sense. However, I do not understand how ackers work. Are > they spouts/bolts exactly the same as my original spouts/bolts and they > perform different functions? Also, is there any way in my code to > differentiate the behavior of a spout/bolt with its acker? > > Thanks, > Nick > > 2015-02-23 14:09 GMT-05:00 Nathan Leung <[email protected]>: > > with 4 workers, by default, you would also have 4 acker tasks (1 / >> worker), which is why you might see 8 tasks. >> >> On Mon, Feb 23, 2015 at 1:56 PM, Nick R. Katsipoulakis < >> [email protected]> wrote: >> >>> Hello, >>> >>> I am trying to control my cluster's parallelism and I want to achieve >>> the following: 1 worker per component, and 1 executioner per worker and 1 >>> task per executioner. In order to achieve the former, I submit my >>> components to the topology as follows: >>> >>> Config conf = new Config(); >>> >>> TopologyBuilder builder = new TopologyBuilder(); >>> builder.setSpout("spout_1", >>> new GreenSpout(), 1) >>> .setNumTasks(1); >>> builder.setBolt("bolt_1", >>> new GreenBolt(), 1) >>> .setNumTasks(1) >>> .directGrouping("spout_1"); >>> builder.setBolt("bolt_2", >>> new RedBolt(), 1) >>> .setNumTasks(1) >>> .directGrouping("bolt_1"); >>> builder.setBolt("bolt_3", >>> new YellowBolt(), 1) >>> .setNumTasks(1) >>> .directGrouping("bolt_2"); >>> >>> conf.setDebug(true); >>> conf.setNumWorkers(4); >>> StormSubmitter.submitTopology("experimental-top", conf, >>> builder.createTopology()); >>> >>> The above not only sets the parallelism hint (executioner threads per >>> worker) to 1, but also the number of workers per component to 1. However, >>> when I submit my topology, and I perform a storm list, I can see that I >>> have 4 workers and 8 tasks running. Is this normal? My goal is to have each >>> component executed by 1 thread on each machine. Am I missing something? >>> >>> Thanks, >>> Nick >>> >>> >>> -- >>> Nikolaos Romanos Katsipoulakis, >>> University of Pittsburgh, PhD candidate >>> >> >> > > > -- > Nikolaos Romanos Katsipoulakis, > University of Pittsburgh, PhD candidate >
