As far as I know, setting parallelism for a spout/bolt doesn't increase the number of threads in which it is executed. If you need to increase the number of threads, you need to set the num_workers to be the number you need.
On Thu, Jan 29, 2015 at 4:17 PM, 余昊 <[email protected]> wrote: > Hi, > > I set the parallelism of a bolt to 3 with the java code: > *builder.setBolt("myBolt", myBolt, 3);* > > I think, 3 myBolt instances would be created in 3 tasks each of which > would run in a different thread (i.e. executor) in parallel. To prove > that, I printed out the bolt instance name in the prepare() method of > MyBolt class, expecting 3 different instance names in the worker log files. > > However, things did not always go like that. I tested twice, the second > topology worked as I expected. But in the first topology, 6701,6702,6703 > ports were assigned to "myBolt", and I found the exactly same bolt instance > name in worker-6701.log and worker-6702.log files, which were different > from worker-6703.log file. > > So how to explain this? > > ------------------------------ > Hao Yu > -- Regards, Pandian
