Sharding

Intent

Sharding pattern means divide the data store into horizontal partitions or shards. Each shard has the same schema, but holds its own distinct subset of the data. A shard is a data store in its own right (it can contain the data for many entities of different types), running on a server acting as a storage node.

Class diagram

Applicability

This pattern offers the following benefits:

• You can scale the system out by adding further shards running on additional storage nodes.
• A system can use off the shelf commodity hardware rather than specialized (and expensive) computers for each storage node.
• You can reduce contention and improved performance by balancing the workload across shards.
• In the cloud, shards can be located physically close to the users that will access the data.

Credits

• Sharding pattern