Deploy a Replica Set for Testing and Development部署用于测试和开发的副本集

Overview概述

Three member replica sets provide enough redundancy to survive most network partitions and other system failures. 三成员副本集提供了足够的冗余，可以经受大多数网络分区和其他系统故障。These sets also have sufficient capacity for many distributed read operations. 这些集合还具有足够的容量，可用于许多分布式读取操作。Replica sets should always have an odd number of members. 副本集的成员数应始终为奇数。This ensures that elections will proceed smoothly. 这将确保选举顺利进行。For more about designing replica sets, see the Replication overview.有关设计副本集的更多信息，请参阅复制概述。

Requirements要求

For test and development systems, you can run your mongod instances on a local system, or within a virtual instance.对于测试和开发系统，您可以在本地系统或虚拟实例中运行mongod实例。

Before you can deploy a replica set, you must install MongoDB on each system that will be part of your replica set. 在部署副本集之前，必须在将成为副本集一部分的每个系统上安装MongoDB。If you have not already installed MongoDB, see the installation tutorials.如果尚未安装MongoDB，请参阅安装教程。

Each member must be able to connect to every other member. 每个成员必须能够连接到其他每个成员。For instructions on how to check your connection, see Test Connections Between all Members.有关如何检查连接的说明，请参阅测试所有成员之间的连接。

Considerations注意事项

mongod --bind_ip localhost,My-Example-Associated-Hostname

mongosh --host My-Example-Associated-Hostname
mongosh --host 198.51.100.1

Procedure程序

1. Create the necessary data directories for each member by issuing a command similar to the following:通过发出与以下类似的命令，为每个成员创建必要的数据目录：

   mkdir -p /srv/mongodb/rs0-0  /srv/mongodb/rs0-1 /srv/mongodb/rs0-2

   This will create directories called "rs0-0", "rs0-1", and "rs0-2", which will contain the instances' database files.这将创建名为“rs0-0”、“rs0-1”和“rs0.2”的目录，其中将包含实例的数据库文件。

2. Start your mongod instances in their own shell windows by issuing the following commands:通过发出以下命令，在自己的shell窗口中启动mongod实例：

   Warning警告

   Before binding to a non-localhost (e.g. publicly accessible) IP address, ensure you have secured your cluster from unauthorized access. 在绑定到非本地主机（例如，可公开访问的）IP地址之前，请确保已保护集群免受未经授权的访问。For a complete list of security recommendations, see Security Checklist. 有关安全建议的完整列表，请参阅安全检查表。At minimum, consider enabling authentication and hardening network infrastructure.至少，考虑启用身份验证和强化网络基础设施。

   First member:第一成员：

   mongod --replSet rs0 --port 27017 --bind_ip localhost,<hostname(s)|ip address(es)> --dbpath /srv/mongodb/rs0-0  --oplogSize 128

   Second member:第二成员：

   mongod --replSet rs0 --port 27018 --bind_ip localhost,<hostname(s)|ip address(es)> --dbpath /srv/mongodb/rs0-1  --oplogSize 128

   Third member:第三成员：

   mongod --replSet rs0 --port 27019 --bind_ip localhost,<hostname(s)|ip address(es)> --dbpath /srv/mongodb/rs0-2 --oplogSize 128

   This starts each instance as a member of a replica set named rs0, each running on a distinct port, and specifies the path to your data directory with the --dbpath setting. 这会将每个实例作为名为rs0的副本集的成员启动，每个副本集在不同的端口上运行，并使用--dbpath设置指定数据目录的路径。If you are already using the suggested ports, select different ports.如果您已经在使用建议的端口，请选择其他端口。

   The instances bind to both the localhost and the ip address of the host.实例绑定到本地主机和主机的ip地址。

   The --oplogSize setting reduces the disk space that each mongod instance uses. --oplogSize设置减少了每个mongod实例使用的磁盘空间。[1] This is ideal for testing and development deployments as it prevents overloading your machine. 这是测试和开发部署的理想选择，因为它可以防止机器过载。For more information on this and other configuration options, see Configuration File Options.有关此配置选项和其他配置选项的详细信息，请参阅配置文件选项。

3. Connect to one of your mongod instances through mongosh. 通过mongosh连接到您的一个mongod实例。You will need to indicate which instance by specifying its port number. 您需要通过指定其端口号来指示哪个实例。For the sake of simplicity and clarity, you may want to choose the first one, as in the following command;为了简单明了，您可能需要选择第一个，如下命令所示；

   mongosh --port 27017

4. In mongosh, use rs.initiate() to initiate the replica set. 在mongosh中，使用rs.initiate()启动副本集。You can create a replica set configuration object in mongosh environment, as in the following example:您可以在mongosh环境中创建副本集配置对象，如以下示例所示：

   rsconf = {
     _id: "rs0",
     members: [
       {
        _id: 0,
        host: "<hostname>:27017"
       },
       {
        _id: 1,
        host: "<hostname>:27018"
       },
       {
        _id: 2,
        host: "<hostname>:27019"
       }
      ]
   }

   replacing <hostname> with your system's hostname, and then pass the rsconf file to rs.initiate() as follows:将<hostname>替换为系统的主机名，然后将rsconf文件传递给rs.initiate()，如下所示：

   rs.initiate( rsconf )

5. Display the current replica configuration by issuing the following command:通过发出以下命令显示当前副本配置：

   rs.conf()

   The replica set configuration object resembles the following:副本集配置对象类似于以下内容：

   {
      "_id" : "rs0",
      "version" : 1,
      "protocolVersion" : NumberLong(1),
      "members" : [
         {
            "_id" : 0,
            "host" : "<hostname>:27017",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {
            },
            "secondaryDelaySecs" : NumberLong(0),
            "votes" : 1
         },
         {
            "_id" : 1,
            "host" : "<hostname>:27018",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {
            },
            "secondaryDelaySecs" : NumberLong(0),
            "votes" : 1
         },
         {
            "_id" : 2,
            "host" : "<hostname>:27019",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {
            },
            "secondaryDelaySecs" : NumberLong(0),
            "votes" : 1
         }
      ],
      "settings" : {
         "chainingAllowed" : true,
         "heartbeatIntervalMillis" : 2000,
         "heartbeatTimeoutSecs" : 10,
         "electionTimeoutMillis" : 10000,
         "catchUpTimeoutMillis" : -1,
         "getLastErrorModes" : {
         },
         "getLastErrorDefaults" : {
            "w" : 1,
            "wtimeout" : 0
         },
         "replicaSetId" : ObjectId("598f630adc9053c6ee6d5f38")
      }
   }

Check the status of your replica set at any time with the rs.status() operation.随时使用rs.status()操作检查副本集的状态。