MongoDB sharding, how does it balance when adding new nodes?

Question

I am trying to understand MongoDB and the concept of sharding. If we start with two nodes and partitions, say customer data based on last name, where A th M data is stored on node 1 and N thru Z data is stored on node 2. What happens when we want to scale and add more nodes? I just don’t understand how this will work.

Answer 1

If you have 2 nodes, this does not mean that the data is divided into 2 parts. It can be divided into sections to say that 10 pieces and 6 of them are on the server. 1 ane rest is on server 2.

MongoDB

:

• http://www.mongodb.org/display/DOCS/Sharding+Introduction

• http://www.mongodb.org/display/DOCS/Choosing+a+Shard+Key

Answer 2

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