I am new to scalding world. My scalding job will have multiple stages, and I need to tune each stage individually.
I have found that we might be able to change the number of reducers by using withReducers. Also, I am able to set the split size for the input data by the job config. However, I didn't see there is any way to change the number of mappers for my sub-tasks on the fly.
Did I miss something? Does anyone know how to specify the number of mappers for my sub-tasks? Thanks.
Got some answers/ideas might be helpful for someone else who shared the same question.
It is much easier to control reducers compared to mappers.
Mappers are controlled by hadoop without a similar simple knob. You can set some config parameters to give hadoop an idea of how many map tasks to launch.
This stack overflow may be helpful: Setting the number of map tasks and reduce tasks
One workaround I could think of is changing your major task to small ones, which you could individually tweak the size (# of mappers) of your input data.
