I would say, configure so that your total parallelism matches the number of cores available (i.e. if you have a topology with X spouts, Y boltAs and Z boltBs, make it so that X+Y+Z = cores available). And one worker per machine, inter-JVM communications are expensive. When you have more bolts and spouts than available cores, you're losing time to switching available cpus between them. In an ideal world, your topology will be able to allocate the cores with components in a 1-1 fashion without switching.
Regards, JG On Mon, Jun 8, 2015 at 6:56 PM, Seungtack Baek < [email protected]> wrote: > I was reading on "How many Workers should I use?" (link > <https://storm.apache.org/documentation/FAQ.html#how-many-workers-should-i-use?>) > and it suggested us to use parallelism hint that is same as the total > number of cores in the cluster. I just want to clarify that this > parallelism is solely for this bolt only, without counting acker and spout > task, right? > > Also, even if then number of bolts (not tasks) increases, are we still > encouraged to keep the parallelism = total cores in cluster? > > Thanks, > Baek > > > *Seungtack Baek | Precocity, LLC* > > Tel/Direct: (972) 378-1030 | Mobile: (214) 477-5715 > > *[email protected] <[email protected]>* | > www.precocityllc.com > > > This is the end of this message. > > -- > -- Javier González Nicolini
