What does multiple task inside an executor in storm signifies?

Question

What is the benefit of using multiple task in an executor in storm topology. I mean I couldn't understand that except doing multiple thing, we can achieve any speed or parallelism?

Answer 1

Michael G.Noll wrote a great tutorial that should help you to understand storm parallelism.

Usually a topology runs one task per executor. However since you cannot increase the number of tasks while a topology is running you can declare multiple tasks per executor in order to scale up parallelism over time.

There is no specific use case to have multiple tasks per executor other than the possibility to increase the topology parallelism.