Question

Minimum on what data size Sharding is recommended in MongoDB? Suppose my database size is 1 GB is sharding necessary? if I do not create shard will that work for me, for this data size.

Answer 1

The decision to enable sharding in your environment isn’t a matter of size so much as it is for scaling to meet demand.
Sharding is especially useful for very large datasets with very high throughput requirements. Sharding provides horizontal scaling that allows you to store and retrieve the data across multiple machines in your environment so that the query load is spread out and reducing the overhead on any one single server. With sharding, you add more machines to support data growth and the demands of reads & writes that your traffic requires.
As for when to shard your data, you would want to get ahead of the problem and enable sharding as soon as the requirement to scale is known. Once you make the decision to shard your data, it is important to perform the necessary capacity planning to ensure that you don’t hit a system performance wall at the most inconvenient time.
Credits : https://groups.google.com/forum/embed/#!topic/mongodb-user/C5x80X6ozHY