进入 "C:\Program Files\MongoDB\Server\8.0" 目录，创建 data2，data3，date4，log2，log3，log4 文件夹，创建 mongod2.conf，mongod3.conf，mongod4.conf 文件

mongod2.conf

storage:
  dbPath: C:\Program Files\MongoDB\Server\8.0\data2

systemLog:
  destination: file
  logAppend: true
  path:  C:\Program Files\MongoDB\Server\8.0\log2\mongod.log

net:
  port: 27018
  bindIp: 127.0.0.1

replication:
  replSetName: rs

mongod3.conf

storage:
  dbPath: C:\Program Files\MongoDB\Server\8.0\data3

systemLog:
  destination: file
  logAppend: true
  path:  C:\Program Files\MongoDB\Server\8.0\log3\mongod.log

net:
  port: 27019
  bindIp: 127.0.0.1

replication:
  replSetName: rs

mongod4.conf

storage:
  dbPath: C:\Program Files\MongoDB\Server\8.0\data4

systemLog:
  destination: file
  logAppend: true
  path:  C:\Program Files\MongoDB\Server\8.0\log4\mongod.log

net:
  port: 27020
  bindIp: 127.0.0.1

replication:
  replSetName: rs

修改 bin/mongod.cfg 中的 replication 和上面保持一致

管理员模式下执行命令

cd "C:\Program Files\MongoDB\Server\8.0\bin"
mongod.exe --config "C:\Program Files\MongoDB\Server\8.0\mongod2.conf" --serviceName "MongoDB2" --serviceDisplayName "MongoDB2" --install
mongod.exe --config "C:\Program Files\MongoDB\Server\8.0\mongod3.conf" --serviceName "MongoDB3" --serviceDisplayName "MongoDB3" --install
mongod.exe --config "C:\Program Files\MongoDB\Server\8.0\mongod4.conf" --serviceName "MongoDB4" --serviceDisplayName "MongoDB4" --install

net start MongoDB2
net start MongoDB3
net start MongoDB4

打开 mongosh.exe (需要下载)

rs_conf = {
  _id: "rs",
  members: [
    { _id: 0, host: "127.0.0.1:27017", priority: 1 },
    { _id: 1, host: "127.0.0.1:27018", priority: 2 },
    { _id: 2, host: "127.0.0.1:27019", priority: 3 },
    { _id: 3, host: "127.0.0.1:27020", arbiterOnly: true }
  ]
}
rs.initiate(rs_conf)

连接

const mongo = await mongoose.connect(
  'mongodb://127.0.0.1:27017,127.0.0.1:27018,127.0.0.1:27019,127.0.0.1:27020/db?replicaSet=rs'
)