Deploy a Sharded Cluster部署分片群集

Connectivity连通性

Each member of a sharded cluster must be able to connect to all other members in the cluster. 分片集群的每个成员都必须能够连接到集群中的所有其他成员。This includes all shards and config servers. Ensure that network and security systems, including all interface and firewalls, allow these connections.这包括所有的分片和配置服务器。确保网络和安全系统，包括所有接口和防火墙，允许这些连接。

Hostnames and Configuration主机名和配置

Security安全

This tutorial does not include the required steps for configuring Internal/Membership Authentication or Role-Based Access Control.本教程不包括配置内部/成员身份验证或基于角色的访问控制所需的步骤。

In production environments, sharded clusters should employ at minimum x.509 security for internal authentication and client access.在生产环境中，分片集群应至少使用x.509安全性进行内部身份验证和客户端访问。

Create the Config Server Replica Set创建配置服务器副本集

The following steps deploys a config server replica set.以下步骤部署配置服务器副本集。

For a production deployment, deploy a config server replica set with at least three members. 对于生产部署，请部署至少有三个成员的配置服务器副本集。For testing purposes, you can create a single-member replica set.出于测试目的，您可以创建单个成员复制副本集。

For this tutorial, the config server replica set members are associated with the following hosts:在本教程中，配置服务器副本集成员与以下主机关联：

sharding:
  clusterRole: configsvr
replication:
  replSetName: <replica set name>
net:
  bindIp: localhost,<hostname(s)|ip address(es)>

mongod --config <path-to-config-file>

mongod --configsvr --replSet <replica set name> --dbpath <path> --bind_ip localhost,<hostname(s)|ip address(es)>

mongosh --host <hostname> --port <port>

rs.initiate(
  {
    _id: "myReplSet",
    configsvr: true,
    members: [
      { _id : 0, host : "cfg1.example.net:27019" },
      { _id : 1, host : "cfg2.example.net:27019" },
      { _id : 2, host : "cfg3.example.net:27019" }
    ]
  }
)

Once the config server replica set (CSRS) is initiated and up, proceed to creating the shard replica sets.启动并启动配置服务器副本集（CSRS）后，继续创建分片副本集。

Create the Shard Replica Sets创建分片复制副本集

For a production deployment, use a replica set with at least three members. 对于生产部署，请使用至少有三个成员的复制副本集。For testing purposes, you can create a single-member replica set.出于测试目的，您可以创建单个成员复制副本集。

For each shard, use the following steps to create the shard replica set:对于每个分片，请使用以下步骤创建分片副本集：

sharding:
    clusterRole: shardsvr
replication:
    replSetName: <replSetName>
net:
    bindIp: localhost,<ip address>

mongod --config <path-to-config-file>

mongod --shardsvr --replSet <replSetname>  --dbpath <path> --bind_ip localhost,<hostname(s)|ip address(es)>

mongosh --host <hostname> --port <port>

rs.initiate(
  {
    _id : "myReplSet",
    members: [
      { _id : 0, host : "s1-mongo1.example.net:27018" },
      { _id : 1, host : "s1-mongo2.example.net:27018" },
      { _id : 2, host : "s1-mongo3.example.net:27018" }
    ]
  }
)

Start a mongos for the Sharded Cluster为分片集群启动mongos

Start a mongos using either a configuration file or a command line parameter to specify the config servers.使用配置文件或命令行参数启动mongos以指定配置服务器。

sharding:
  configDB: <configReplSetName>/cfg1.example.net:27019,cfg2.example.net:27019
net:
  bindIp: localhost,<hostname(s)|ip address(es)>

mongos --config <path-to-config>

mongos --configdb <configReplSetName>/cfg1.example.net:27019,cfg2.example.net:27019,cfg3.example.net:27019 --bind_ip localhost,<hostname(s)|ip address(es)>

Connect to the Sharded Cluster连接到分片群集

Connect mongosh to the mongos. Specify the host and port on which the mongos is running:将mongosh连接到mongos。指定运行mongos的host和port：

mongosh --host <hostname> --port <port>

Once you have connected mongosh to the mongos, continue to the next procedure to add shards to the cluster.将mongosh连接到mongos后，继续执行下一个过程，将分片添加到集群中。

Add Shards to the Cluster将分片添加到群集

In a mongosh session that is connected to the mongos, use the sh.addShard() method to add each shard to the cluster.在连接到mongos的mongosh会话中，使用sh.addShard()方法将每个分片添加到集群中。

The following operation adds a single shard replica set to the cluster:以下操作将单个分片副本集添加到集群中：

sh.addShard( "<replSetName>/s1-mongo1.example.net:27018,s1-mongo2.example.net:27018,s1-mongo3.example.net:27018")

Repeat these steps until the cluster includes all desired shards.重复这些步骤，直到群集包含所有所需的分片。

Shard a Collection对集合进行分片

To shard a collection, connect mongosh to the mongos and use the sh.shardCollection() method.要分割集合，请将mongosh连接到mongos并使用sh.shardCollection()方法。

MongoDB provides two strategies to shard collections:MongoDB为分片集合提供了两种策略：

• Hashed sharding uses a hashed index of a single field as the shard key to partition data across your sharded cluster.哈希分片使用单个字段的哈希索引作为分片键，在分片集群中对数据进行分区。

  sh.shardCollection("<database>.<collection>", { <shard key field> : "hashed" } )

• Range-based sharding can use multiple fields as the shard key and divides data into contiguous ranges determined by the shard key values.基于范围的分片可以使用多个字段作为分片键，并将数据划分为由分片键值确定的连续范围。

  sh.shardCollection("<database>.<collection>", { <shard key field> : 1, ... } )

Shard Key Considerations分片关键注意事项

Your selection of shard key affects the efficiency of sharding, as well as your ability to take advantage of certain sharding features such as zones. 您对分片键的选择会影响分片的效率，以及您利用某些分片功能（如区域）的能力。To learn how to choose an effective shard key, see Choose a Shard Key.要了解如何选择有效的分片键，请参阅选择分片键。

Starting in version 4.0, mongosh provides the method convertShardKeyToHashed(). 从4.0版本开始，mongosh提供了convertShardKeyToHashed()方法。This method uses the same hashing function as the hashed index and can be used to see what the hashed value would be for a key.此方法使用与哈希索引相同的哈希函数，可以用来查看键的哈希值。