工作原理
MongoDB的复制是基于操作日志oplog，相当于MySQL中的二进制日志，只记录发生改变的记录。复制是将主节点的oplog日志同步并应用到其他从节点的过程。
1.副本集之间的复制是通过oplog日志现实的.备份节点通过查询这个集合就可以知道需要进行复制的操作
2.oplog是节点中local库中的一个固定的集合,在默认情况下oplog初始化大小为空闲磁盘的5%.oplog是capped collection,所以当oplog的空间被占满时,会覆盖最初写入的日志
3.通过改变oplog文档的大小直接改变local所占磁盘空间的大小.可以在配置文件中设置oplogSize参数来指定oplog文档的大小。
4.通过oplog中的操作记录,把数据复制在备份节点.
5.主节点是集中接收写入操作的,MongoDB中的应用连接到主节点进行写入操作，然后记录在主节点操作oplog,从节点成员定期轮询复制此日志并将操作应用于其数据集。
常用命令
rs.conf() 查看副本集配置
rs.status() 查看副本集状态
rs.initiate(config) 初始化副本集
rs.isMaster() 查看是否为主节点
db.getMongo().setSlaveOk(); 赋予副本集副本节点查询数据的权限，副本节点执行
rs.add("ip:port") 新增副本集节点
rs.remove("ip:port") 删除副本集节点
rs.addArb("ip:port") 添加仲裁节点
副本集参数说明
"_id": #集群中节点编号
"name": #成员服务器名称及端口
"health" : #表示成员中的健康状态（0:down;1:up）
"state" : #为0~10，表示成员的当前状态
"stateStr" : #描述该成员是主库（PRIMARY）还是备库（SECONDARY）
"uptime" : #该成员在线时间（秒）
"optime" : #成员最后一次应用日志(oplog)的信息
"optimeDate" : #成员最后一次应用日志(oplog)的时间
"electionTime" : #当前primary从操作日志中选举信息
"electionDate" : #当前primary被选定为primary的日期
"configVersion" : #mongodb版本
"self" : #为true 表示当前节点
开始部署mongod副本集
一、环境准备
操作系统centos6.5 mongodb版本3.6.6
ip地址 主机名 角色
192.168.1.230 mongodb01 副本集主节点
192.168.1.18 mongodb02 副本集副本节点
192.168.1.247 mongodb03 副本集副本节点
关闭3个服务器的防火墙及selinux
二、安装部署mongodb及副本集配置
1、安装部署mongodb
可参考：https://www.cnblogs.com/wusy/p/10405991.html
2、副本集配置
1）yum安装mongodb在做副本集时需在所有服务器配置文件加入以下配置：
replication:
replSetName: repset（副本集名，可自定义） #副本集配置
security: #开启副本集用户认证
authorization: enabled
keyFile: /data/mongodb/keyfile
clusterAuthMode: keyFile
2）源码包构建副本集时，则需加以下语法来配置：
replSet=repset（副本集名） #副本集配置
auth=true #开启副本集用户认证，若为单击模式，则不创建和指定秘钥文件
keyFile=/data2/mongodb-3.6.6/keyfile #指定秘钥文件路径
journal=true #开启journal日志，默认为开启
3、初始化副本集
在任意一台节点初始化都可，但在哪一台做初始化，那么这一台就作为副本集的主节点，这里选择mongodb01（也可使用权重值来控制主副节点）
1）进入mongodb数据库
[root@mongodb01 ~]# mongo --host 192.168.1.230
2）定义副本集配置，这里的_id:repset要与配置文件中所指的副本集名称一致
>config={
... _id:"repset", #务必与配置文件中指定的副本集名称一致
... members:[
... {_id:,host:"192.168.1.230:27017"},
... {_id:,host:"192.168.1.18:27017"},
... {_id:,host:"192.168.1.247:27017"}
... ]
... }
{
"_id" : "repset",
"members" : [
{
"_id" : ,
"host" : "192.168.1.230:27017"
},
{
"_id" : ,
"host" : "192.168.1.18:27017"
},
{
"_id" : ,
"host" : "192.18.1.247:27017"
}
]
}
3)初始化副本集配置
> rs.initiate(config)
{
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
4）查看集群节点状态（health为1表明正常，为0表明异常）
repset:PRIMARY> rs.status()
{
"set" : "repset",
"date" : ISODate("2019-03-02T04:50:47.554Z"),
"myState" : ,
"term" : NumberLong(),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -,
"heartbeatIntervalMillis" : NumberLong(),
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"readConcernMajorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"appliedOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"durableOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
}
},
"lastStableCheckpointTimestamp" : Timestamp(, ),
"members" : [
{
"_id" : ,
"name" : "192.168.1.230:27017",
"health" : ,
"state" : ,
"stateStr" : "PRIMARY",
"uptime" : ,
"optime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"optimeDate" : ISODate("2019-03-02T04:50:38Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -,
"infoMessage" : "could not find member to sync from",
"electionTime" : Timestamp(, ),
"electionDate" : ISODate("2019-03-02T04:50:07Z"),
"configVersion" : ,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : ,
"name" : "192.168.1.18:27017",
"health" : ,
"state" : ,
"stateStr" : "SECONDARY",
"uptime" : ,
"optime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"optimeDurable" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"optimeDate" : ISODate("2019-03-02T04:50:38Z"),
"optimeDurableDate" : ISODate("2019-03-02T04:50:38Z"),
"lastHeartbeat" : ISODate("2019-03-02T04:50:47.382Z"),
"lastHeartbeatRecv" : ISODate("2019-03-02T04:50:46.242Z"),
"pingMs" : NumberLong(),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.1.247:27017",
"syncSourceHost" : "192.168.1.247:27017",
"syncSourceId" : ,
"infoMessage" : "",
"configVersion" :
},
{
"_id" : ,
"name" : "192.168.1.247:27017",
"health" : ,
"state" : ,
"stateStr" : "SECONDARY",
"uptime" : ,
"optime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"optimeDurable" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"optimeDate" : ISODate("2019-03-02T04:50:38Z"),
"optimeDurableDate" : ISODate("2019-03-02T04:50:38Z"),
"lastHeartbeat" : ISODate("2019-03-02T04:50:47.382Z"),
"lastHeartbeatRecv" : ISODate("2019-03-02T04:50:46.183Z"),
"pingMs" : NumberLong(),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.1.230:27017",
"syncSourceHost" : "192.168.1.230:27017",
"syncSourceId" : ,
"infoMessage" : "",
"configVersion" :
}
],
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
repset:PRIMARY>
5）查看是否为主节点（可在其他节点执行查看）
repset:PRIMARY> rs.isMaster()
{
"hosts" : [
"192.168.1.230:27017",
"192.168.1.18:27017",
"192.168.1.247:27017"
],
"setName" : "repset",
"setVersion" : ,
"ismaster" : true,
"secondary" : false,
"primary" : "192.168.1.230:27017",
"me" : "192.168.1.230:27017",
"electionId" : ObjectId("7fffffff0000000000000001"),
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T04:52:28Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T04:52:28Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T04:52:32.106Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
6）可登入副本集副本节点，并查看是否为主节点或副本节点
[root@mongodb02 ~]# mongo --host 192.168.1.18 repset:SECONDARY> repset:SECONDARY> rs.isMaster()
{
"hosts" : [
"192.168.1.230:27017",
"192.168.1.18:27017",
"192.168.1.247:27017"
],
"setName" : "repset",
"setVersion" : ,
"ismaster" : false,
"secondary" : true,
"primary" : "192.168.1.230:27017",
"me" : "192.168.1.18:27017",
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T04:54:18Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T04:54:18Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T04:54:27.819Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
三、登入副本集副本集节点验证数据复制功能（默认副本集的副本节点不能查看数据）
1、在主节点mongodb01上插入数据，在副本节点查看数据
repset:PRIMARY> use test
switched to db test repset:PRIMARY> db.test.save({id:"one",name:"wushaoyu"})
WriteResult({ "nInserted" : })
2、进入副本节点mongodb02查看主库插入的数据
repset:SECONDARY> use test
switched to db test
repset:SECONDARY> show dbs
--02T13::06.503+ E QUERY [js] Error: listDatabases failed:{
"operationTime" : Timestamp(, ),
"ok" : ,
"errmsg" : "not master and slaveOk=false",
"code" : ,
"codeName" : "NotMasterNoSlaveOk",
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
} :
_getErrorWithCode@src/mongo/shell/utils.js::
Mongo.prototype.getDBs@src/mongo/shell/mongo.js::
shellHelper.show@src/mongo/shell/utils.js::
shellHelper@src/mongo/shell/utils.js::
@(shellhelp2)::
注：上面出现了报错
因为主库插入的数据，从库是不具备读的权限的，所以要设置副本节点可以读
repset:SECONDARY> db.getMongo().setSlaveOk(); repset:SECONDARY> db.test.find()
{ "_id" : ObjectId("5c7a0f3a6698c70ef075f0a8"), "id" : "one", "name" : "wushaoyu" } repset:SECONDARY> show tables
test
注：由此看到，副本节点已经把主节点的数据复制过来了（在mongodb03上做同样操作即可）
四、验证故障转移功能，停止当前副本主节点，验证高可用
先停止副本主节点，在查看副本节点的状态，
1）停止副本主节点的mongodb
[root@mongodb01 ~]# ps -ef |grep mongod
mongod : ? :: /usr/bin/mongod -f /etc/mongod.conf
root : pts/ :: grep mongod [root@mongodb01 ~]# kill -
2）登录其他两个副本集节点，查看是否推选出新的主节点
[root@mongodb02 ~]# mongo --host 192.168.1.18 repset:SECONDARY> rs.isMaster()
{
"hosts" : [
"192.168.1.230:27017",
"192.168.1.18:27017",
"192.168.1.247:27017"
],
"setName" : "repset",
"setVersion" : ,
12 "ismaster" : false,
13 "secondary" : true,
14 "primary" : "192.168.1.247:27017",
15 "me" : "192.168.1.18:27017",
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T05:16:41Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T05:16:41Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T05:16:48.433Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
} [root@mongodb03 ~]# mongo --host 192.168.1.247 repset:PRIMARY> rs.isMaster()
{
"hosts" : [
"192.168.1.230:27017",
"192.168.1.18:27017",
"192.168.1.247:27017"
],
"setName" : "repset",
"setVersion" : ,
58 "ismaster" : true,
59 "secondary" : false,
60 "primary" : "192.168.1.247:27017",
61 "me" : "192.168.1.247:27017",
"electionId" : ObjectId("7fffffff0000000000000002"),
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T05:19:31Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T05:19:31Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T05:19:35.282Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
ps：发现主节点宕机之后，mongodb03为新推选出来的主节点
3）在新的主节点mongodb03插入数据，在mongodb02上查看是否同步
[root@mongodb03 ~]# mongo --host 192.168.1.247 repset:PRIMARY> use wsy
switched to db wsy
repset:PRIMARY> db.wsy.save({"name":"wsy"})
WriteResult({ "nInserted" : }) [root@mongodb02 ~]# mongo --host 192.168.1.18 repset:SECONDARY> db.getMongo().setSlaveOk();
repset:SECONDARY> show tables
wsy repset:SECONDARY> db.wsy.find()
{ "_id" : ObjectId("5c7a133007ebf60ac5870bae"), "name" : "wsy" }
由此可看出，数据同步成功
4）启动先前的mongodb01，查看状态，mongodb成为了当前主节点的副本节点，并且在它宕机期间插入的数据也同步了过来
[root@mongodb01 ~]# /etc/init.d/mongod start [root@mongodb01 ~]# mongo --host 192.168.1.230 repset:SECONDARY> rs.isMaster()
{
"hosts" : [
"192.168.1.230:27017",
"192.168.1.18:27017",
"192.168.1.247:27017"
],
"setName" : "repset",
"setVersion" : ,
14 "ismaster" : false,
15 "secondary" : true,
16 "primary" : "192.168.1.247:27017",
17 "me" : "192.168.1.230:27017",
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T05:32:51Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T05:32:51Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T05:32:59.225Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
#开启副本节点读的权限
repset:SECONDARY> db.getMongo().setSlaveOk();
repset:SECONDARY> db.wsy.find()
{ "_id" : ObjectId("5c7a133007ebf60ac5870bae"), "name" : "wsy" }
注：在原来的主节点宕机期间，新选举出来的主机插入的数据，也会同步过来
五、java程序连接副本集测试
public class TestMongoDBReplSet {
public static void main(String[] args) {
try {
List<ServerAddress> addresses = new ArrayList<ServerAddress>();
ServerAddress address1 = new ServerAddress("192.168.1.230" , );
ServerAddress address2 = new ServerAddress("192.168.1.18" , );
ServerAddress address3 = new ServerAddress("192.168.1.247" , );
addresses.add(address1);
addresses.add(address2);
addresses.add(address3);
MongoClient client = new MongoClient(addresses);
DB db = client.getDB( "test");
DBCollection coll = db.getCollection( "testdb");
// 插入
BasicDBObject object = new BasicDBObject();
object.append( "test2", "testval2" );
coll.insert(object);
DBCursor dbCursor = coll.find();
while (dbCursor.hasNext()) {
DBObject dbObject = dbCursor.next();
System. out.println(dbObject.toString());
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
目前看起来支持完美的故障转移了，这个架构是不是比较完美了？其实还有很多地方可以优化
六、副本集开启用户认证模式
1、创建keyFile文件
keyFile文件的作用： 集群之间的安全认证，增加安全认证机制KeyFile（开启keyfile认证就默认开启了auth认证了，为了保证后面可以登录，我已创建了用户）
openssl rand -base64 > /root/keyfile 其中666是文件大小 /root/keyfile ： 文件存放路径
##该key的权限必须是600；也可改为400
chmod 600 /root/keyfile
注：创建秘钥文件可添置mongodb副本集，在创建，防止服务无法启动等原因
2、修改配置文件
security:
authorization: enabled
keyFile: /root/keyfile
clusterAuthMode: keyFile
3、重新启动mongodb节点
[root@ecs-1e54- ~]# mongod -f /etc/mongod.conf
--20T13::11.479+ I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
about to fork child process, waiting until server is ready for connections.
forked process:
child process started successfully, parent exiting
注：此处启动需使用这种指定文件的方式启动。因为本人安装mongodb采用rpm包安装，故启动是可用/etc/init.d/mongod start的方式启动，但是在副本集开启了用户认证的方式下，在采取这种启动方式，因为启动脚本的内容原因，就会报错permission denied，导致启动服务失败。
4、连接验证
[root@ecs-2c32 mongodb]# mongo 192.168.1.193:
MongoDB shell version v4.0.0
connecting to: mongodb://192.168.1.193:27017/test
MongoDB server version: 4.0.
repset:PRIMARY> show dbs
--20T13::49.421+ E QUERY [js] Error: listDatabases failed:{
"operationTime" : Timestamp(, ),
"ok" : ,
"errmsg" : "command listDatabases requires authentication",
"code" : ,
"codeName" : "Unauthorized",
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"hKSQT5ImwURihIb0w/CeT4vu44E="),
"keyId" : NumberLong("")
}
}
} :
_getErrorWithCode@src/mongo/shell/utils.js::
Mongo.prototype.getDBs@src/mongo/shell/mongo.js::
shellHelper.show@src/mongo/shell/utils.js::
shellHelper@src/mongo/shell/utils.js::
@(shellhelp2)::
可看出此处需要用户认证方可查看数据
repset:PRIMARY> use admin
switched to db admin
repset:PRIMARY> db.auth('admin','admin') repset:PRIMARY> show dbs
admin .000GB
config .000GB
local .000GB
七、仲裁节点
副本集只能由主节点来接收写操作，而副本节点可以专门用来读操作
当副本节点增多时，主节点的复制压力就会增大，这是就可以添加仲裁节点
在副本集里，仲裁节点仲裁节点不存储数据，只是负责故障转移的群体投票，这样就少了数据复制的压力
1）添加仲裁节点192.168.1.7
repset:PRIMARY> rs.addArb("192.168.1.7:27017")
{
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
2）查看节点信息
repset:PRIMARY> rs.isMaster()
{
"hosts" : [
"192.168.1.18:27017",
"192.168.1.247:27017",
"192.168.1.230:27017"
],
"arbiters" : [
"192.168.1.7:27017"
],
"setName" : "repset",
"setVersion" : ,
13 "ismaster" : true,
14 "secondary" : false,
15 "primary" : "192.168.1.18:27017",
16 "me" : "192.168.1.18:27017",
"electionId" : ObjectId("7fffffff0000000000000003"),
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T09:38:33Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T09:38:33Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T09:38:45.054Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" : ,
"operationTime" : Timestamp(, ),
"$clusterTime" : {
"clusterTime" : Timestamp(, ),
"signature" : {
"hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong()
}
}
}
3）登录仲裁节点查看状态
repset:ARBITER> db.getMongo().setSlaveOk();
repset:ARBITER> rs.isMaster()
{
"hosts" : [
"192.168.1.18:27017",
"192.168.1.247:27017",
"192.168.1.230:27017"
],
"arbiters" : [
"192.168.1.7:27017"
],
"setName" : "repset",
"setVersion" : ,
"ismaster" : false,
"secondary" : false,
"primary" : "192.168.1.18:27017",
"arbiterOnly" : true,
"me" : "192.168.1.7:27017",
"lastWrite" : {
"opTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"lastWriteDate" : ISODate("2019-03-02T09:43:10Z"),
"majorityOpTime" : {
"ts" : Timestamp(, ),
"t" : NumberLong()
},
"majorityWriteDate" : ISODate("2019-03-02T09:43:10Z")
},
"maxBsonObjectSize" : ,
"maxMessageSizeBytes" : ,
"maxWriteBatchSize" : ,
"localTime" : ISODate("2019-03-02T09:43:14.154Z"),
"logicalSessionTimeoutMinutes" : ,
"minWireVersion" : ,
"maxWireVersion" : ,
"readOnly" : false,
"ok" :
}