MongoDB Sharding
MongoDB is a popular open-source NoSQL database known for its ability to store and manage large volumes of unstructured or semi-structured data. To scale horizontally, MongoDB uses a technique called sharding, which involves distributing data across multiple servers, or nodes, in a cluster. Each shard in the MongoDB cluster is responsible for storing a subset of the data. This allows MongoDB to handle much larger datasets than could be stored on a single server and ensures high availability and fault tolerance. The data is distributed based on a shard key, which is selected based on the field or fields used most often for querying data. This distribution of data across multiple nodes enables MongoDB to handle growing demands without a significant performance drop.
https://en.wikipedia.org/wiki/MongoDB
In MongoDB's sharding architecture, the shard key plays a crucial role in determining how data is divided across different shards. The shard key is a field in the document that is indexed and used to partition the data. When the data is written to the MongoDB database, the shard key value is used to calculate which shard the data will reside on. This partitioning process allows for horizontal scaling, ensuring that as the database grows, it can continue to handle the increased load by simply adding more shards. The data is distributed in such a way that each shard contains a unique subset of the data, which improves the database’s performance for read and write operations.
https://en.wikipedia.org/wiki/MongoDB
The sharding process in MongoDB involves multiple components that work together to manage and distribute the data. These components include the mongos query router, which directs queries to the appropriate shard based on the shard key; the MongoDB config servers, which store metadata about the sharding process; and the shards themselves, which contain the actual data. MongoDB's sharding strategy provides MongoDB high availability and MongoDB fault tolerance through MongoDB data replication. Each shard typically has multiple replicas, and in case a shard or MongoDB node fails, another MongoDB replica can take over, ensuring that the database continues to function without downtime. Despite its benefits, sharding requires careful planning, especially in choosing the MongoDB shard key, to ensure optimal MongoDB performance and to avoid MongoDB data skew or MongoDB hotspots across shards.