How to deploy a sharded MongoDB cluster.

The deployment of a MongoDB sharded cluster requires the following steps:

1. Install MongoDB on all nodes, including configuration servers, router nodes, and shard nodes. You can download and install the binary files suitable for your operating system from the MongoDB official website.
2. Set up servers: Choose one or more servers as configuration servers. These servers will store the metadata information for the entire cluster, including metadata for shard collections and shard nodes. Create a replica set on the configuration servers with at least 3 nodes to ensure high availability.
3. Router nodes: Choose one or more servers as router nodes, also known as mongos nodes. The router nodes receive client requests and route them to the appropriate shard nodes. Select one node as the primary node in the replica set and configure the members of the replica set on other nodes.
4. Shard nodes: Choose multiple servers as shard nodes. Shard nodes store the actual data, with each one storing different parts of the collection. Select one node as the primary node in the replica set configuration, and configure the other nodes as members of the replica set.
5. Start a configuration server: Launch the mongod process on the configuration server and configure it as a member of the configuration replica set. Ensure that the nodes in the configuration replica set are functioning properly and elect a primary node.
6. Start the router node: Start the mongos process on the router node and configure it as a member of the configuration replica set. Make sure that the nodes in the configuration replica set are running smoothly and elect a primary node.
7. Start shard nodes: Start the mongod process on each shard node and configure it as a member of the replica set. Ensure that the nodes in the replica set are running properly and elect a primary node.
8. Add shard: Use the sh.addShard() command on the mongos node to add a shard node to the cluster, enabling it to distribute data across the shard nodes.
9. Create a shard collection: Enable sharding on the mongos node using the sh.enableSharding() command, and shard the collection to shard nodes using the sh.shardCollection() command.
10. Validation of the cluster: Connect to the mongos node using the MongoDB client, perform some read and write operations to confirm that the cluster is functioning properly.

This is a basic deployment process for a MongoDB sharded cluster, the specific configuration and parameter settings may vary depending on the environment and requirements. It is recommended to refer to the official MongoDB documentation and tutorials for more detailed guidance.