mongodb副本集介绍、mongodb副本集搭建、 mongodb副本集测试
mongodb副本集介绍
- MongoDB早期版本使用master-slave，一主一从和MySQL主从基本是一致的，但salve在此架构中为只读，当主库宕机后，从库不能自动切换为主.
- 目前已经淘汰master-salve模式，改成副本集，副本集架构也是为了实现MongoDB的高可用，这种模式下有一个主（primary），和多个从（secondary）只读，支持他们设置权重，当主宕机后，权重最高的从切换为主.
- 在此架构中还能够创建一个仲裁（arbiter）的角色，它只负责裁决，而不存储数据.
- 在此架构中读写数据都是在主上，要想实现负载均衡的目的须要手动指定读库的目标server.
MongoDB副本集架构图
原理很简单一个primary，secondary至少是一个，也能够是多个secondary，除了多个secondary以外，还能够加一个Arbiter，Arbiter叫作仲裁，当Primary宕机后，Arbiter能够很准确的告知Primary宕掉了，但可能Primary认为本身没有宕掉，这样的话就会出现脑裂，为了防止脑裂就增长了Arbiter这个角色，尤为是数据库坚定不能出现脑裂的状态，脑裂会致使数据会紊乱，数据一旦紊乱恢复就很是麻烦.linux
变迁图
说明：Primary宕机后，其中secondary就成为一个新的Primary，另一个secondary依然是secondary的角色. 对于MySQL主历来讲，即便作一主多从，万一master宕机后，可让从成为新的主，但这过程是须要手动的更改的. 可是在MongoDB副本集架构当中呢，它彻底都是自动的，rimary宕机后，其中secondary就成为一个新的Primary，另一个secondary能够自动识别新的primary.mongodb
mongodb副本集搭建
准备三台机器: 192.168.2.115 (primary)
192.168.2.116 (secondary)
192.168.2.117 (secondary)
三台机器都须要安装MongoDB，primary已安装过，两台secondary须要安装，因步骤同样，在此不作演示.shell
编辑三台机器的配置文件
Primary机器: [root@root-01 ~]# vim /etc/mongod.conf net: port: 27017 bindIp: 127.0.0.1,192.168.2.115 # Listen to local interface only, comment to listen on all interfaces. 说明:作副本集bindIp 要监听本机IP和内网IP #replication: //把#去掉，并增两行 replication: oplogSizeMB: 20 replSetName: annalinux //定义副本集的名字 重启MongoDB服务: [root@root-01 ~]# systemctl restart mongod [root@root-01 ~]# ps aux |grep mongod mongod 39020 7.3 4.8 1016828 48880 ? Sl 17:18 0:00 /usr/bin/mongod -f /etc/mongod.conf root 39050 0.0 0.0 112664 964 pts/0 S+ 17:19 0:00 grep --color=auto mongod Secondary1机器: [root@root-02 ~]# vim /etc/mongod.conf net: port: 27017 bindIp: 127.0.0.1,192.168.2.116 # Listen to local interface only, comment to listen on all interfaces. 说明:作副本集bindIp 要监听本机IP和内网IP #replication: //把#去掉，并增两行 replication: oplogSizeMB: 20 replSetName: annalinux //定义副本集的名字 重启MongoDB服务: [root@root-02 ~]# systemctl restart mongod [root@root-02 ~]# ps aux |grep mongod mongod 2303 2.2 4.6 1016336 46404 ? Sl 17:28 0:00 /usr/bin/mongod -f /etc/mongod.conf root 2331 0.0 0.0 112664 968 pts/0 S+ 17:28 0:00 grep --color=auto mongod Secondary2机器: [root@root-03 ~]# vim /etc/mongod.conf net: port: 27017 bindIp: 127.0.0.1,192.168.2.117 # Listen to local interface only, comment to listen on all interfaces. 说明:作副本集bindIp 要监听本机IP和内网IP #replication: //把#去掉，并增两行 replication: oplogSizeMB: 20 replSetName: annalinux //定义副本集的名字 重启MongoDB服务: [root@root-03 ~]# systemctl restart mongod [root@root-03 ~]# ps aux |grep mongod mongod 2735 3.5 4.3 1016340 43932 ? Sl 17:46 0:00 /usr/bin/mongod -f /etc/mongod.conf root 2761 0.0 0.0 112664 968 pts/0 R+ 17:47 0:00 grep --color=auto mongod
链接MongoDB --Primary机器
[root@root-01 ~]# mongo MongoDB shell version v3.4.9 connecting to: mongodb://127.0.0.1:27017 MongoDB server version: 3.4.9 Server has startup warnings: 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database. 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted. 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'. 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never' 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'. 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never' 2017-10-20T17:18:53.740+0800 I CONTROL [initandlisten]
配置副本集
说明:在哪台机器上执行这一步，那么哪台机器就会成为primary数据库
> config={_id:"annalinux",members:[{_id:0,host:"192.168.2.115:27017"},{_id:1,host:"192.168.2.116:27017"},{_id:2,host:"192.168.2.117:27017"}]}
{
"_id" : "annalinux",
"members" : [
{
"_id" : 0,
"host" : "192.168.2.115:27017"
},
{
"_id" : 1,
"host" : "192.168.2.116:27017"
},
{
"_id" : 2,
"host" : "192.168.2.117:27017"
}
]
}
config={_id:"annalinux" --> annalinux(副本集的名字)
members --> 指定成员
rs.initiate(config) -->初始化
> rs.initiate(config)
{ "ok" : 1 }
rs.status() -->查看副本集状态
说明：能够看到192.168.2.115 显示："stateStr" : "PRIMARY"
192.168.2.116和192.168.2.117 分别显示： "stateStr" : "SECONDARY"vim
annalinux:SECONDARY> rs.status()
{
"set" : "annalinux",
"date" : ISODate("2017-10-20T10:02:15.484Z"),
"myState" : 1,
"term" : NumberLong(1),
"heartbeatIntervalMillis" : NumberLong(2000),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"appliedOpTime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
}
},
"members" : [
{
"_id" : 0,
"name" : "192.168.2.115:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 2602,
"optime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-10-20T10:02:12Z"),
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(1508493631, 1),
"electionDate" : ISODate("2017-10-20T10:00:31Z"),
"configVersion" : 1,
"self" : true
},
{
"_id" : 1,
"name" : "192.168.2.116:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 115,
"optime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-10-20T10:02:12Z"),
"optimeDurableDate" : ISODate("2017-10-20T10:02:12Z"),
"lastHeartbeat" : ISODate("2017-10-20T10:02:13.519Z"),
"lastHeartbeatRecv" : ISODate("2017-10-20T10:02:13.875Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "192.168.2.117:27017",
"configVersion" : 1
},
{
"_id" : 2,
"name" : "192.168.2.117:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 115,
"optime" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1508493732, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2017-10-20T10:02:12Z"),
"optimeDurableDate" : ISODate("2017-10-20T10:02:12Z"),
"lastHeartbeat" : ISODate("2017-10-20T10:02:13.519Z"),
"lastHeartbeatRecv" : ISODate("2017-10-20T10:02:13.881Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "192.168.2.115:27017",
"configVersion" : 1
}
],
"ok" : 1
}
annalinux:PRIMARY>
mongodb副本集测试
建立库 和 建立集合-->在primary机器
切换到admin库:
annalinux:PRIMARY> use admin
switched to db admin
建立mydb库:
annalinux:PRIMARY> use mydb
switched to db mydb
建立acc集合，并插入一些数据:
annalinux:PRIMARY> db.acc.insert({AccountID:1,USerName:"123",password:"123456"})
WriteResult({ "nInserted" : 1 })
查看全部库:
annalinux:PRIMARY> show dbs
admin 0.000GB
db1 0.000GB
local 0.000GB
mydb 0.000GB
test 0.000GB
切换到mydb库：
annalinux:PRIMARY> show dbs
admin 0.000GB
db1 0.000GB
local 0.000GB
mydb 0.000GB
test 0.000GB
进入mydb库:
annalinux:PRIMARY> use mydb
switched to db mydb
查看集合：
annalinux:PRIMARY> show tables
acc
登陆Secondary1机器
说明: 和primary机器数据一致，说明搭建副本集成功了bash
登陆：
[root@root-02 ~]# mongo
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.9
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
http://docs.mongodb.org/
Questions? Try the support group
http://groups.google.com/group/mongodb-user
Server has startup warnings:
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten]
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten]
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten]
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten]
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2017-10-20T17:28:02.614+0800 I CONTROL [initandlisten]
查看全部库：
annalinux:SECONDARY> show dbs;
2017-10-20T18:18:50.600+0800 E QUERY [thread1] Error: listDatabases failed:{
"ok" : 0,
"errmsg" : "not master and slaveOk=false", //提示不是master，slaveOK=false
"code" : 13435,
"codeName" : "NotMasterNoSlaveOk"
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
Mongo.prototype.getDBs@src/mongo/shell/mongo.js:62:1
shellHelper.show@src/mongo/shell/utils.js:769:19
shellHelper@src/mongo/shell/utils.js:659:15
@(shellhelp2):1:1
须要执行:
annalinux:SECONDARY> rs.slaveOk()
再show dbs就没问题:
annalinux:SECONDARY> show dbs;
admin 0.000GB
db1 0.000GB
local 0.000GB
mydb 0.000GB
test 0.000GB
进入mydb库:
annalinux:SECONDARY> use mydb
switched to db mydb
查看集合:
annalinux:SECONDARY> show tables
acc
登陆Secondary2机器
说明: 和primary机器数据一致，说明搭建副本集成功了架构
[root@root-03 ~]# mongo
MongoDB shell version v3.4.9
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.9
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
http://docs.mongodb.org/
Questions? Try the support group
http://groups.google.com/group/mongodb-user
Server has startup warnings:
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten]
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten]
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten]
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten]
2017-10-20T17:46:53.757+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2017-10-20T17:46:53.758+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2017-10-20T17:46:53.758+0800 I CONTROL [initandlisten]
查看全部库：
annalinux:SECONDARY> show dbs;
2017-10-20T18:18:50.600+0800 E QUERY [thread1] Error: listDatabases failed:{
"ok" : 0,
"errmsg" : "not master and slaveOk=false", //提示不是master，slaveOK=false
"code" : 13435,
"codeName" : "NotMasterNoSlaveOk"
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
Mongo.prototype.getDBs@src/mongo/shell/mongo.js:62:1
shellHelper.show@src/mongo/shell/utils.js:769:19
shellHelper@src/mongo/shell/utils.js:659:15
@(shellhelp2):1:1
须要执行:
annalinux:SECONDARY> rs.slaveOk()
再show dbs就没问题:
annalinux:SECONDARY> show dbs;
admin 0.000GB
db1 0.000GB
local 0.000GB
mydb 0.000GB
test 0.000GB
进入mydb库:
annalinux:SECONDARY> use mydb
switched to db mydb
查看集合:
annalinux:SECONDARY> show tables
acc
副本集更改权重模拟primary宕机
说明：在primary机器添加防火墙规则，伪装primary宕机，看看是如何变成一个新的primary。app
rs.config() -->查看权重
说明:能够看到三个节点都是"priority" : 1, 也就是说三个节点权重都是同样负载均衡
annalinux:PRIMARY> rs.config()
{
"_id" : "annalinux",
"version" : 1,
"protocolVersion" : NumberLong(1),
"members" : [
{
"_id" : 0,
"host" : "192.168.2.115:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.2.116:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.2.117:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : 60000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("59e9c9342025e71e7bcebc7b")
}
}
在primary机器加一条iptables规则，把27017端口禁掉
[root@root-01 ~]# iptables -I INPUT -p tcp --dport 27017 -j DROP
查看副本集状态--在Secondary1机器
说明: 本来192.168.2.115是primary，如今192.168.2.117变成了primarytcp
查看副本集状态：
annalinux:SECONDARY> rs.status()
{
"set" : "annalinux",
"date" : ISODate("2017-10-20T10:40:27.907Z"),
"myState" : 2,
"term" : NumberLong(2),
"syncingTo" : "192.168.2.117:27017",
"heartbeatIntervalMillis" : NumberLong(2000),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
},
"appliedOpTime" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
},
"durableOpTime" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
}
},
"members" : [
{
"_id" : 0,
"name" : "192.168.2.115:27017",
"health" : 0,
"state" : 8,
"stateStr" : "(not reachable/healthy)", //显示不能获取状态值
"uptime" : 0,
"optime" : {
"ts" : Timestamp(0, 0),
"t" : NumberLong(-1)
},
"optimeDurable" : {
"ts" : Timestamp(0, 0),
"t" : NumberLong(-1)
},
"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
"optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"),
"lastHeartbeat" : ISODate("2017-10-20T10:40:26.805Z"),
"lastHeartbeatRecv" : ISODate("2017-10-20T10:40:27.796Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "Couldn't get a connection within the time limit",
"configVersion" : -1
},
{
"_id" : 1,
"name" : "192.168.2.116:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 4345,
"optime" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
},
"optimeDate" : ISODate("2017-10-20T10:40:22Z"),
"syncingTo" : "192.168.2.117:27017",
"configVersion" : 1,
"self" : true
},
{
"_id" : 2,
"name" : "192.168.2.117:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 2405,
"optime" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
},
"optimeDurable" : {
"ts" : Timestamp(1508496022, 1),
"t" : NumberLong(2)
},
"optimeDate" : ISODate("2017-10-20T10:40:22Z"),
"optimeDurableDate" : ISODate("2017-10-20T10:40:22Z"),
"lastHeartbeat" : ISODate("2017-10-20T10:40:26.709Z"),
"lastHeartbeatRecv" : ISODate("2017-10-20T10:40:26.089Z"),
"pingMs" : NumberLong(0),
"electionTime" : Timestamp(1508495934, 1),
"electionDate" : ISODate("2017-10-20T10:38:54Z"),
"configVersion" : 1
}
],
"ok" : 1
}
把原来的primary机器设置的iptables规则删除掉
说明:把在原来的primary机器设置的iptables规则删除掉，它也不能变会primary，除非设置了权重
[root@root-01 ~]# iptables -D INPUT -p tcp --dport 27017 -j DROP
在新的primary机器（192.168.2.117）设置权重
设置变量:
annalinux:PRIMARY> cfg=rs.config()
{
"_id" : "annalinux",
"version" : 1,
"protocolVersion" : NumberLong(1),
"members" : [
{
"_id" : 0,
"host" : "192.168.2.115:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.2.116:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.2.117:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : 60000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("59e9c9342025e71e7bcebc7b")
}
}
设置权重:
annalinux:PRIMARY> cfg.members[0].priority=3
3
annalinux:PRIMARY> cfg.members[1].priority=2
2
annalinux:PRIMARY> cfg.members[2].priority=1
1
让设置的权重生效:
annalinux:PRIMARY> rs.reconfig(cfg)
{ "ok" : 1 }
查看权重:
annalinux:PRIMARY> rs.config()
2017-10-20T18:54:07.529+0800 E QUERY [thread1] Error: error doing query: failed: network error while attempting to run command 'replSetGetConfig' on host '127.0.0.1:27017' :
DB.prototype.runCommand@src/mongo/shell/db.js:132:1
DB.prototype.adminCommand@src/mongo/shell/db.js:150:16
rs.conf@src/mongo/shell/utils.js:1271:16
@(shell):1:1
2017-10-20T18:54:07.533+0800 I NETWORK [thread1] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2017-10-20T18:54:07.534+0800 I NETWORK [thread1] reconnect 127.0.0.1:27017 (127.0.0.1) ok
annalinux:SECONDARY>
说明: 提示这台机器不是primary,已经发生了改变，这台机器变成了Secondary了
从新执行rs.config()：
annalinux:SECONDARY> rs.config()
{
"_id" : "annalinux",
"version" : 2,
"protocolVersion" : NumberLong(1),
"members" : [
{
"_id" : 0,
"host" : "192.168.2.115:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 3,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.2.116:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 2,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.2.117:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : 60000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("59e9c9342025e71e7bcebc7b")
}
}
说明:能够看到192.168.2.115的权重显示: "priority" : 3
192.168.2.116的权重显示: "priority" : 2
192.168.2.117的权重显示: "priority" : 1