MongoDB设置 Replication Sets

电玩女神 2022-06-12 03:06 133阅读 0赞

MongoDB 高可用可用分两种 ：  
  
  
 Master-Slave 主从复制 ： 只需要在某一个服务启动时加上–master 参数, 而另一个服务加上–slave 与–source 参数, 即可实现同步 。  
 MongoDB的最新版本已不再推荐此方案。  
  
 Replica Sets 复制集 ：MongoDB 在 1.6 版本对开发了新功能 replica set,这比之前的 replication 功能要强大一 些,增加了故障自动切换  
 和自动修复成员节点,各个 DB 之间数据完全一致,大大降低了维 护成功。auto shard 已经明确说明不支持 replication paris, 建议使用   
 replica set,replica set 故障切换完全自动。  
  
 Replica Sets 的结构非常类似一个集群 ，其中一个节点如果出现故障, 其它节点马上会将业务 接过来而无须停机操作。  
  
![wKioL1keisChS4cRAAB351tADa8038.png-wh_500x0-wm_3-wmp_4-s_2959113685.png][]  
  
  
192.168.110.131(node1)  
192.168.110.132(node2)  
192.168.110.133(node3)  
  
  
  
一、MongoDB安装  
      
 \[root@node1 ~\]\#  vim /etc/yum.repos.d/Mongodb.repo  
  
  
 \[mongodb-org-3.4\]  
 name=MongoDB Repository  
 baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.4/x86\_64/  
 gpgcheck=1  
 enabled=1  
 gpgkey=https://www.mongodb.org/static/pgp/server-3.4.asc   
  
  
\[root@node1 ~\]\#  yum install -y mongodb-org  
  
  
\[root@node1 ~\]\#  service mongod start  
 Starting mongod:                                           \[  OK  \]  
      
 \[root@node1 ~\]\# ps aux|grep mong  
 mongod    1361  5.7 14.8 351180 35104 ?        Sl   01:26   0:01 /usr/bin/mongod -f /etc/mongod.conf  
  
  
 更改数据存放目录：  
  
  
\[root@node1 ~\]\# mkdir -p /mongodb/data  
  
\[root@node1 ~\]\# chown -R mongod:mongod /mongodb/  
  
\[root@node1 ~\]\# ll /mongodb/  
 total 4  
 drwxr-xr-x 2 mongod mongod 4096 May 18 02:04 data  
  
  
      
\[root@node1 ~\]\#  grep -v "^\#" /etc/mongod.conf |grep -v "^$"  
 systemLog:  
   destination: file  
   logAppend: true  
   path: /var/log/mongodb/mongod.log  
 storage:  
   dbPath: /mongodb/data  
   journal:  
     enabled: true  
 processManagement:  
   fork: true  \# fork and run in background  
   pidFilePath: /var/run/mongodb/mongod.pid  \# location of pidfile  
 net:  
   port: 27017  
   bindIp: 0.0.0.0 \# Listen to local interface only, comment to listen on all interfaces.  
  
  
\[root@node1 ~\]\#  service mongod start  
 Starting mongod:                                           \[  OK  \]  
      
    node2，node2与上面一样  
  
  
二、配置 Replication Sets  
      
介绍一下涉及到的参数  
  
 \--oplogSize 日志操作文件的大小  
  
 \--dbpath   数据文件路径  
  
 \--logpath  日志文件路径  
  
 \--port        端口号，默认是27017.我这里使用的也是这个端口号.  
  
 \--replSet   复制集的名字，一个replica sets中的每个节点的这个参数都要用一个复制集名字，这里是test.  
  
 \--replSet test/  这个后面跟的是其他standard节点的ip和端口  
  
 \--maxConns   最大连接数  
  
 \--fork       后台运行  
  
 \--logappend   日志文件循环使用，如果日志文件已满，那么新日志覆盖最久日志。  
  
 \--keyFile       标识同一集群的认证私钥  
  
  
 其中在启动节点时一定要加上oplogSize 的参数 为其设置大小，不然在64位操作系统上的mongodb,oplogs都相当大-可能是5%的磁盘空间。  
 要根据情况设置个合理的值。  
      
    v3.4.4上的参数：  
  
  
\[root@node1 ~\]\# vim /etc/mongod.conf   
  
 replication:  
     oplogSizeMB: 1024  
     replSetName: rs0  
      
    使用Keyfile存取控制部署复制集：  
  
    openssl rand -base64 756 > <path-to-keyfile>  
 chmod 400 <path-to-keyfile>  
  
  
 Configuration File  
  
 If using a configuration file, set the security.keyFile option to the keyfile’s path, and the replication.replSetName option to the replica set name:  
  
  
 security:  
   keyFile: <path-to-keyfile>  
 replication:  
   replSetName: <replicaSetName>  
  
 Command Line  
  
  
 If using the command line option, start the mongod with the --keyFile and --replSet parameters:  
  
  
 mongod --keyFile <path-to-keyfile> --replSet <replicaSetName>  
      
 配置带密钥文件的 Replication Sets：  
      
  \[root@node1 ~\]\#  openssl rand -base64 756 > /mongodb/mongokey  
  
  \[root@node1 ~\]\# cat /mongodb/mongokey   
  
 gxpcgjyFj2qE8b9TB/0XbdRVYH9VDb55NY03AHwxCFU58MUjJMeez844i1gaUo/t  
 .....  
 .....  
    
 \[root@node1 ~\]\#  chmod 400 /mongodb/mongokey   
  
 \[root@node1 ~\]\#  chown mongod:mongod /mongodb/mongokey   
  
 \[root@node1 ~\]\# ll /mongodb/  
 total 8  
 drwxr-xr-x 4 mongod mongod 4096 May 19 18:39 data  
 \-r-------- 1 mongod mongod 1024 May 19 18:29 mongokey  
  
  
  \[root@node1 ~\]\# vim /etc/mongod.conf  
    \#security:  
 security:  
     keyFile: /mongodb/mongokey  
  
 \#operationProfiling:  
  
 \#replication:  
 replication:  
    oplogSizeMB: 1024  
     replSetName: rs0  
      
    \[root@node1 ~\]\# service mongod restart  
 Stopping mongod:                                           \[  OK  \]  
 Starting mongod:                                           \[  OK  \]  
      
    \[root@node1 ~\]\#  iptables -I INPUT 4 -m state --state NEW -p tcp --dport 27017  -j ACCEPT  
      
    复制hosts文件：  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/hosts root@node2.pancou.com:/mongodb/  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/hosts root@node3.pancou.com:/mongodb/  
  
    复制密钥文件：  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey root@node3.pancou.com:/mongodb/  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey root@node3.pancou.com:/mongodb/  
      
    复制配置文件：  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf root@node2.pancou.com:/etc/  
    \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf root@node3.pancou.com:/etc/  
  
    注意:双方都要按照rsync和openssh-clients  
  
  
    \[root@node1 ~\]\# mongo  
    > help  
 db.help()                    help on db methods  
 db.mycoll.help()             help on collection methods  
 sh.help()                    sharding helpers  
 rs.help()                    replica set helpers  
    .....  
  
  
    >  rs.help()  
 rs.status()                                \{ replSetGetStatus : 1 \} checks repl set status  
 rs.initiate()                              \{ replSetInitiate : null \} initiates set with default settings  
 rs.initiate(cfg)                           \{ replSetInitiate : cfg \} initiates set with configuration cfg  
 rs.conf()                                  get the current configuration object from local.system.replset  
    .....  
  
  
    >  rs.status()  
 \{   
 "info" : "run rs.initiate(...) if not yet done for the set",  
 "ok" : 0,  
 "errmsg" : "no replset config has been received",  
 "code" : 94,  
 "codeName" : "NotYetInitialized"  
    \}  
  
  
    >  rs.initiate()  
 \{   
 "info2" : "no configuration specified. Using a default configuration for the set",  
 "me" : "node1.pancou.com:27017",  
 "ok" : 1  
 \}  
  
  
    rs0:OTHER>   
 rs0:PRIMARY> rs.status()  
 \{   
 "set" : "rs0",  
 "date" : ISODate("2017-05-18T17:00:49.868Z"),  
 "myState" : 1,  
 "term" : NumberLong(1),  
 "heartbeatIntervalMillis" : NumberLong(2000),  
 "optimes" : \{   
 "lastCommittedOpTime" : \{   
 "ts" : Timestamp(1495126845, 1),  
 "t" : NumberLong(1)  
 \},  
 "appliedOpTime" : \{   
 "ts" : Timestamp(1495126845, 1),  
 "t" : NumberLong(1)  
 \},  
 "durableOpTime" : \{   
 "ts" : Timestamp(1495126845, 1),  
 "t" : NumberLong(1)  
 \}  
 \},  
 "members" : \[  
 \{   
 "\_id" : 0,  
 "name" : "node1.pancou.com:27017",  
 "health" : 1,  
 "state" : 1,  
 "stateStr" : "PRIMARY",  
 "uptime" : 1239,  
 "optime" : \{   
 "ts" : Timestamp(1495126845, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDate" : ISODate("2017-05-18T17:00:45Z"),  
 "infoMessage" : "could not find member to sync from",  
 "electionTime" : Timestamp(1495126824, 2),  
 "electionDate" : ISODate("2017-05-18T17:00:24Z"),  
 "configVersion" : 1,  
 "self" : true  
 \}  
 \],  
 "ok" : 1  
 \}  
  
  
    rs0:PRIMARY>  rs.add("node2.pancou.com")  
 \{ "ok" : 1 \}  
 rs0:PRIMARY> rs.add("node3.pancou.com")  
 \{ "ok" : 1 \}  
    rs0:PRIMARY>  rs.status()  
 \{   
 "set" : "rs0",  
 "date" : ISODate("2017-05-18T17:08:47.724Z"),  
 "myState" : 1,  
 "term" : NumberLong(1),  
 "heartbeatIntervalMillis" : NumberLong(2000),  
 "optimes" : \{   
 "lastCommittedOpTime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "appliedOpTime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "durableOpTime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \}  
 \},  
 "members" : \[  
 \{   
 "\_id" : 0,  
 "name" : "node1.pancou.com:27017",  
 "health" : 1,              //表明状态正常  
 "state" : 1,               //1表示是PRIMARY，2表示是slave  
 "stateStr" : "PRIMARY",    //表示此机器是主库  
 "uptime" : 1717,  
 "optime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDate" : ISODate("2017-05-18T17:08:45Z"),  
 "electionTime" : Timestamp(1495126824, 2),  
 "electionDate" : ISODate("2017-05-18T17:00:24Z"),  
 "configVersion" : 3,  
 "self" : true  
 \},  
 \{   
 "\_id" : 1,  
 "name" : "node2.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 64,  
 "optime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDate" : ISODate("2017-05-18T17:08:45Z"),  
 "optimeDurableDate" : ISODate("2017-05-18T17:08:45Z"),  
 "lastHeartbeat" : ISODate("2017-05-18T17:08:46.106Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-18T17:08:47.141Z"),  
 "pingMs" : NumberLong(0),  
 "syncingTo" : "node1.pancou.com:27017",  
 "configVersion" : 3  
 \},  
 \{   
 "\_id" : 2,  
 "name" : "node3.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 55,  
 "optime" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495127325, 1),  
 "t" : NumberLong(1)  
 \},  
 "optimeDate" : ISODate("2017-05-18T17:08:45Z"),  
 "optimeDurableDate" : ISODate("2017-05-18T17:08:45Z"),  
 "lastHeartbeat" : ISODate("2017-05-18T17:08:46.195Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-18T17:08:46.924Z"),  
 "pingMs" : NumberLong(0),  
 "syncingTo" : "node2.pancou.com:27017",  
 "configVersion" : 3  
 \}  
 \],  
 "ok" : 1  
 \}  
      
    rs0:PRIMARY>  db.isMaster()  
 \{   
 "hosts" : \[  
 "node1.pancou.com:27017",  
 "node2.pancou.com:27017",  
 "node3.pancou.com:27017"  
 \],  
 "setName" : "rs0",  
 "setVersion" : 3,  
 "ismaster" : true,  
 "secondary" : false,  
 "primary" : "node1.pancou.com:27017",  
 "me" : "node1.pancou.com:27017",  
 "electionId" : ObjectId("7fffffff0000000000000001"),  
 "lastWrite" : \{   
 "opTime" : \{   
 "ts" : Timestamp(1495127705, 1),  
 "t" : NumberLong(1)  
 \},  
 "lastWriteDate" : ISODate("2017-05-18T17:15:05Z")  
 \},  
 "maxBsonObjectSize" : 16777216,  
 "maxMessageSizeBytes" : 48000000,  
 "maxWriteBatchSize" : 1000,  
 "localTime" : ISODate("2017-05-18T17:15:11.146Z"),  
 "maxWireVersion" : 5,  
 "minWireVersion" : 0,  
 "readOnly" : false,  
 "ok" : 1  
 \}  
      
    rs0:PRIMARY> use testdb  
    rs0:PRIMARY>  show collections  
 testcoll  
 rs0:PRIMARY> db.testcoll.find()  
 \{ "\_id" : ObjectId("591dd9f965cc255a5373aefa"), "name" : "tom", "age" : 25 \}  
  
  
  
  到从库上查看：  
  
   node2:  
    rs0:SECONDARY>  rs.slaveOk()  
 rs0:SECONDARY> show dbs  
 admin   0.000GB  
 local   0.000GB  
 testdb  0.000GB  
 rs0:SECONDARY> use testdb  
 switched to db testdb  
 rs0:SECONDARY>  show collections  
 testcoll  
 rs0:SECONDARY>  db.testcoll.find()  
 \{ "\_id" : ObjectId("591dd9f965cc255a5373aefa"), "name" : "tom", "age" : 25 \}  
 rs0:SECONDARY>   
      
    node3:  
  
  
    rs0:SECONDARY>  rs.slaveOk()  
 rs0:SECONDARY> show dbs  
 admin   0.000GB  
 local   0.000GB  
 testdb  0.000GB  
 rs0:SECONDARY> use testdb  
 switched to db testdb  
 rs0:SECONDARY> show collections  
 testcoll  
 rs0:SECONDARY> db.testcoll.find()  
 \{ "\_id" : ObjectId("591dd9f965cc255a5373aefa"), "name" : "tom", "age" : 25 \}  
 rs0:SECONDARY>   
  
  
    主从操作日志  
  
  
    rs0:PRIMARY> use local  
 switched to db local  
 rs0:PRIMARY> show collections  
 me  
 oplog.rs  
 replset.election  
 replset.minvalid  
 startup\_log  
 system.replset  
 rs0:PRIMARY> db.oplog.rs.find()  
 \{ "ts" : Timestamp(1495126824, 1), "h" : NumberLong("3056083863196084673"), "v" : 2, "op" : "n", "ns" : "", "o" : \{ "msg" : "initiating set" \} \}  
 \{ "ts" : Timestamp(1495126825, 1), "t" : NumberLong(1), "h" : NumberLong("7195178065440751511"), "v" : 2, "op" : "n", "ns" : "", "o" : \{ "msg" : "new primary" \} \}  
 \{ "ts" : Timestamp(1495126835, 1), "t" : NumberLong(1), "h" : NumberLong("5723995478292318850"), "v" : 2, "op" : "n", "ns" : "", "o" : \{ "msg" : "periodic noop" \} \}  
 \{ "ts" : Timestamp(1495126845, 1), "t" : NumberLong(1), "h" : NumberLong("-3772304067699003381"), "v" : 2, "op" : "n", "ns" : "", "o"  
  
  
三、查看配置信息    
  
  
    rs0:PRIMARY>  db.printReplicationInfo()  
 configured oplog size:   1024MB  
 log length start to end: 2541secs (0.71hrs)  
 oplog first event time:  Fri May 19 2017 01:00:24 GMT+0800 (CST)  
 oplog last event time:   Fri May 19 2017 01:42:45 GMT+0800 (CST)  
 now:                     Fri May 19 2017 01:42:48 GMT+0800 (CST)  
 rs0:PRIMARY>   
  
  
 db.oplog.rs.find()：查看复制集产生的日志  
  
 db.printReplicationInfo()：查看操作日志的一些基本信息，如日志大小、日志启用时间。  
  
 db.printSlaveReplicationInfo()：查看所有slave延迟情况。  
  
  
 rs0:PRIMARY> db.printSlaveReplicationInfo()  
 source: node2.pancou.com:27017  
 syncedTo: Fri May 19 2017 01:47:15 GMT+0800 (CST)  
 0 secs (0 hrs) behind the primary   
 source: node3.pancou.com:27017  
 syncedTo: Fri May 19 2017 01:47:15 GMT+0800 (CST)  
 0 secs (0 hrs) behind the primary   
      
     db.system.replset.find()：查看复制集  
  
  
    配置信息：  
  
  
    rs0:PRIMARY>  db.system.replset.find()  
 \{ "\_id" : "rs0", "version" : 3, "protocolVersion" : NumberLong(1), "members" : \[ \{ "\_id" : 0, "host" : "node1.pancou.com:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : \{  \}, "slaveDelay" : NumberLong(0), "votes" : 1 \}, \{ "\_id" : 1, "host" : "node2.pancou.com:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : \{  \}, "slaveDelay" : NumberLong(0), "votes" : 1 \}, \{ "\_id" : 2, "host" : "node3.pancou.com:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : \{  \}, "slaveDelay" : NumberLong(0), "votes" : 1 \} \], "settings" : \{ "chainingAllowed" : true, "heartbeatIntervalMillis" : 2000, "heartbeatTimeoutSecs" : 10, "electionTimeoutMillis" : 10000, "catchUpTimeoutMillis" : 2000, "getLastErrorModes" : \{  \}, "getLastErrorDefaults" : \{ "w" : 1, "wtimeout" : 0 \}, "replicaSetId" : ObjectId("591dd3284fc6957e660dc933") \} \}  
   
   rs0:PRIMARY>  db.system.replset.find().forEach(printjson)  这种方式更直观  
  
  
  
  
四、主从切换：  
      
    1、把node3冰冻30秒  
      
    rs0:SECONDARY>  rs.freeze(30)  
    \{ "ok" : 1 \}  
  
  
    2、把node1 PRIMARY降级、  
  
    rs0:PRIMARY>  rs.stepDown(30)  
 2017-05-19T02:09:27.945+0800 E QUERY    \[thread1\] Error: error doing query: failed: network error while attempting to run command 'replSetStepDown' 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.stepDown@src/mongo/shell/utils.js:1261:12  
 @(shell):1:1  
 2017-05-19T02:09:27.947+0800 I NETWORK  \[thread1\] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed  
 2017-05-19T02:09:27.949+0800 I NETWORK  \[thread1\] reconnect 127.0.0.1:27017 (127.0.0.1) ok  
      
    30秒后就变成从了  
 rs0:SECONDARY>  rs.status()  
 \{   
 "set" : "rs0",  
 "date" : ISODate("2017-05-18T18:12:09.732Z"),  
 "myState" : 2,  
 "term" : NumberLong(2),  
 "syncingTo" : "node2.pancou.com:27017",  
 "heartbeatIntervalMillis" : NumberLong(2000),  
 "optimes" : \{   
 "lastCommittedOpTime" : \{   
 "ts" : Timestamp(1495131128, 1),  
 "t" : NumberLong(2)  
 \},  
 "appliedOpTime" : \{   
 "ts" : Timestamp(1495131128, 1),  
 "t" : NumberLong(2)  
 \},  
 "durableOpTime" : \{   
 "ts" : Timestamp(1495131128, 1),  
 "t" : NumberLong(2)  
 \}  
 \},  
 "members" : \[  
 \{   
 "\_id" : 0,  
 "name" : "node1.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 5519,  
 "optime" : \{   
 "ts" : Timestamp(1495131128, 1),  
 "t" : NumberLong(2)  
 \},  
 "optimeDate" : ISODate("2017-05-18T18:12:08Z"),  
 "syncingTo" : "node2.pancou.com:27017",  
 "configVersion" : 3,  
 "self" : true  
 \},  
 \{   
 "\_id" : 1,  
 "name" : "node2.pancou.com:27017",  
 "health" : 1,  
 "state" : 1,  
 "stateStr" : "PRIMARY",  
 "uptime" : 3866,  
 "optime" : \{   
 "ts" : Timestamp(1495131118, 1),  
 "t" : NumberLong(2)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495131118, 1),  
 "t" : NumberLong(2)  
 \},  
 "optimeDate" : ISODate("2017-05-18T18:11:58Z"),  
 "optimeDurableDate" : ISODate("2017-05-18T18:11:58Z"),  
 "lastHeartbeat" : ISODate("2017-05-18T18:12:08.333Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-18T18:12:08.196Z"),  
 "pingMs" : NumberLong(0),  
 "electionTime" : Timestamp(1495130977, 1),  
 "electionDate" : ISODate("2017-05-18T18:09:37Z"),  
 "configVersion" : 3  
 \},  
 \{   
 "\_id" : 2,  
 "name" : "node3.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 3857,  
 "optime" : \{   
 "ts" : Timestamp(1495131118, 1),  
 "t" : NumberLong(2)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495131118, 1),  
 "t" : NumberLong(2)  
 \},  
 "optimeDate" : ISODate("2017-05-18T18:11:58Z"),  
 "optimeDurableDate" : ISODate("2017-05-18T18:11:58Z"),  
 "lastHeartbeat" : ISODate("2017-05-18T18:12:08.486Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-18T18:12:08.116Z"),  
 "pingMs" : NumberLong(0),  
 "syncingTo" : "node2.pancou.com:27017",  
 "configVersion" : 3  
 \}  
 \],  
 "ok" : 1  
 \}  
 rs0:SECONDARY>   
  
  
  
五、增减节点  
      
    1、增加节点  
  
        通过oplog增加节点，这种方式使数据的同步完全依赖于oplog,即oplog中有多少操作日志，这些操作日志就完全在新添加的节点中执行一遍，以完成同步 。  
  
       在上面有一个3节点的复制集基础上，现在想配置并启动一个新节点，将其加入现在复制集环境中。  
         
  
       \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/hosts root@node2.pancou.com:/etc/  
         
       \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey root@node4.pancou.com:/mongodb/  
  
  
       \[root@node1 ~\]\# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf root@node4.pancou.com:/etc/  
  
  
       \[root@node4 ~\]\# iptables -I INPUT 4 -m state --state NEW -p tcp --dport 27017  -j ACCEPT  
         
       在主上添加新节点：  
  
  
       rs0:PRIMARY>  rs.add("node4.pancou.com")  
 \{ "ok" : 1 \}  
         
       rs0:PRIMARY>  rs.status()  
 \{   
 "set" : "rs0",  
 "date" : ISODate("2017-05-19T12:12:57.697Z"),  
 "myState" : 1,  
 "term" : NumberLong(8),  
 "heartbeatIntervalMillis" : NumberLong(2000),  
 "optimes" : \{   
 "lastCommittedOpTime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "appliedOpTime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "durableOpTime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \}  
 \},  
 "members" : \[  
 \{   
 "\_id" : 0,  
 "name" : "node1.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 159,  
 "optime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDate" : ISODate("2017-05-19T12:12:51Z"),  
 "optimeDurableDate" : ISODate("2017-05-19T12:12:51Z"),  
 "lastHeartbeat" : ISODate("2017-05-19T12:12:56.111Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-19T12:12:57.101Z"),  
 "pingMs" : NumberLong(0),  
 "syncingTo" : "node3.pancou.com:27017",  
 "configVersion" : 4  
 \},  
 \{   
 "\_id" : 1,  
 "name" : "node2.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 189,  
 "optime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDate" : ISODate("2017-05-19T12:12:51Z"),  
 "optimeDurableDate" : ISODate("2017-05-19T12:12:51Z"),  
 "lastHeartbeat" : ISODate("2017-05-19T12:12:56.111Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-19T12:12:57.103Z"),  
 "pingMs" : NumberLong(0),  
 "syncingTo" : "node3.pancou.com:27017",  
 "configVersion" : 4  
 \},  
 \{   
 "\_id" : 2,  
 "name" : "node3.pancou.com:27017",  
 "health" : 1,  
 "state" : 1,  
 "stateStr" : "PRIMARY",  
 "uptime" : 191,  
 "optime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDate" : ISODate("2017-05-19T12:12:51Z"),  
 "electionTime" : Timestamp(1495195800, 1),  
 "electionDate" : ISODate("2017-05-19T12:10:00Z"),  
 "configVersion" : 4,  
 "self" : true  
 \},  
 \{   
 "\_id" : 3,  
 "name" : "node4.pancou.com:27017",  
 "health" : 1,  
 "state" : 2,  
 "stateStr" : "SECONDARY",  
 "uptime" : 71,  
 "optime" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDurable" : \{   
 "ts" : Timestamp(1495195971, 1),  
 "t" : NumberLong(8)  
 \},  
 "optimeDate" : ISODate("2017-05-19T12:12:51Z"),  
 "optimeDurableDate" : ISODate("2017-05-19T12:12:51Z"),  
 "lastHeartbeat" : ISODate("2017-05-19T12:12:56.122Z"),  
 "lastHeartbeatRecv" : ISODate("2017-05-19T12:12:56.821Z"),  
 "pingMs" : NumberLong(1),  
 "syncingTo" : "node3.pancou.com:27017",  
 "configVersion" : 4  
 \}  
 \],  
 "ok" : 1  
 \}  
  
  
  
  
 查看状态：  
  
  
 rs0:SECONDARY>  rs.slaveOk()  
 rs0:SECONDARY> show dbs  
 admin   0.000GB  
 local   0.000GB  
 testdb  0.000GB  
 rs0:SECONDARY> use testdb  
 switched to db testdb  
 rs0:SECONDARY> show collections  
 testcoll  
 rs0:SECONDARY>  db.testcoll.find()  
 \{ "\_id" : ObjectId("591dd9f965cc255a5373aefa"), "name" : "tom", "age" : 25 \}  
 rs0:SECONDARY>   
 rs0:SECONDARY> db.isMaster()  
 \{   
 "hosts" : \[  
 "node1.pancou.com:27017",  
 "node2.pancou.com:27017",  
 "node3.pancou.com:27017",  
 "node4.pancou.com:27017"  
 \],  
 "setName" : "rs0",  
 "setVersion" : 4,  
 "ismaster" : false,  
 "secondary" : true,  
 "primary" : "node3.pancou.com:27017",  
 "me" : "node4.pancou.com:27017",  
 "lastWrite" : \{   
 "opTime" : \{   
 "ts" : Timestamp(1495196261, 1),  
 "t" : NumberLong(8)  
 \},  
 "lastWriteDate" : ISODate("2017-05-19T12:17:41Z")  
 \},  
 "maxBsonObjectSize" : 16777216,  
 "maxMessageSizeBytes" : 48000000,  
 "maxWriteBatchSize" : 1000,  
 "localTime" : ISODate("2017-05-19T12:17:44.104Z"),  
 "maxWireVersion" : 5,  
 "minWireVersion" : 0,  
 "readOnly" : false,  
 "ok" : 1  
 \}  
 rs0:SECONDARY>   
  
  
     2、减少节点  
  
  
        rs0:PRIMARY>  rs.remove("node4.pancou.com:27017")  
 \{ "ok" : 1 \}  
          
        rs0:PRIMARY>  db.isMaster()  
 \{   
 "hosts" : \[  
 "node1.pancou.com:27017",  
 "node2.pancou.com:27017",  
 "node3.pancou.com:27017"  
 \],  
 "setName" : "rs0",  
 "setVersion" : 5,  
 "ismaster" : true,  
 "secondary" : false,  
 "primary" : "node3.pancou.com:27017",  
 "me" : "node3.pancou.com:27017",  
 "electionId" : ObjectId("7fffffff0000000000000008"),  
 "lastWrite" : \{   
 "opTime" : \{   
 "ts" : Timestamp(1495196531, 1),  
 "t" : NumberLong(8)  
 \},  
 "lastWriteDate" : ISODate("2017-05-19T12:22:11Z")  
 \},  
 "maxBsonObjectSize" : 16777216,  
 "maxMessageSizeBytes" : 48000000,  
 "maxWriteBatchSize" : 1000,  
 "localTime" : ISODate("2017-05-19T12:22:19.874Z"),  
 "maxWireVersion" : 5,  
 "minWireVersion" : 0,  
 "readOnly" : false,  
 "ok" : 1  
 \}  
 rs0:PRIMARY>

[wKioL1keisChS4cRAAB351tADa8038.png-wh_500x0-wm_3-wmp_4-s_2959113685.png]: /images/20220612/6d5e0aa0fbcf4734b5eebac5ac88dbe8.png