Can we add more Amazon Elastic Mapreduce instances into an existing Amazon Elastic Mapreduce instances?

Question

I am new to Amazon Services and facing some issues.

Suppose I am running some Job Flow on Amazon Elastic Mapreduce with total 3 instances. While running my job flow on it I found that my job is taking more time to execute. And in such case I need to add more instances into it so that my instances will increase and hence job will execute fast.

My question is that How to add such instance into an existing instances? Because If we terminate existed instance and again create the new instances with more number is time consuming.

Is there anyway to do it? If yes then please suggest me. I am doing all this task through CLI. So please share the anwers with commands too along with GUI steps in AWS Management Console.

Thanks.

Answer 1

Yes, you can do this with the command line tool

to add more instances to the core group:

elastic-mapreduce --modify-instance-group CORE --instance-count 40

To create a task group (no datanodes), with 40 instances:

elastic-mapreduce --add-instance-group TASK --instance-count 40 --instance-type c1.medium

Answer 2

It's important to note that CORE instance-group instances can not be reduced since they participate as data nodes. They can be increased only. TASK instances only do processing and can be increased and reduced.