Do I use the same key-value storage (RockDBs) in 2 different StreamTask same time?

Question

I use Apache as Samza framework for Kafka and I need to share the same RockDBs key-value storage between 2 Tasks.

Is what I can do so without having concurrency on storage Key value?

Answer 1

I deployed 2 Tasks with same Key-value storage and it's working.

So yes we can.

Answer 2

As of Samza 0.12.0 there is no supported way of sharing stores between tasks. Each store is instantiated (isolated) for each task.

For more info, see the "Local State" section here: http://samza.apache.org/learn/documentation/0.12/container/state-management.html