一、配置文件 /etc/mongod.conf

[root@mongo01~]#egrep-v"^(#|$)"/etc/mongod.confsystemLog:destination:filelogAppend:truepath:/data/mongodb/log/rs1.logstorage:dbPath:/data/mongodb/datadirectoryPerDB:truejournal:enabled:trueprocessManagement:fork:true#forkandruninbackgroundpidFilePath:/data/mongodb/conf/mongod.pid#locationofpidfilenet:port:27027replication:oplogSizeMB:50000replSetName:rs1[root@mongo01~]#[root@mongo01~]#ls/data/mongodb/arbiterconfdatalogstartaribiter.sh[root@mongo01~]#ls/data/mongodb/arbiter/arbiter.confconfdatalog[root@mongo01~]#egrep-v"^(#|$)"/data/mongodb/arbiter/arbiter.confsystemLog:destination:filelogAppend:truepath:/data/mongodb/arbiter/log/rs1.logstorage:dbPath:/data/mongodb/arbiter/datadirectoryPerDB:truejournal:enabled:trueprocessManagement:fork:true#forkandruninbackgroundpidFilePath:/data/mongodb/arbiter/conf/mongod.pid#locationofpidfilenet:port:27029replication:oplogSizeMB:50000replSetName:rs1[root@mongo01~]#cat/data/mongodb/startarbiter.sh#!/bin/sh./etc/rc.d/init.d/functionscd${0%/*}/arbiterdaemon--usermongod"mongod--configarbiter.conf"[root@mongo01~]#

注意：arbiter.conf文件的属主、属组为mongod


二、启动服务，配置副本集

servicemongodstart/data/mongodb/startaribiter.sh

启动第二个节点，然后在primary上操作如下：

rs.initiate()rs.add("mongodb2.example.net")rs.add("mongodb3.example.net")rs.addArb("mongodb1.example.net:27029")

如果希望降低primary的优先级：

cfg=rs.conf()cfg.members[2].priority=0.5rs.reconfig(cfg)rs.status()

实现复制后，在从节点上查看数据如下：

SECONDARY>rs.slaveOk()SECONDARY>showcollections

三、 使用keyFile实现复制验证

在主节点上创建群集用户及密码如下：

admin=db.getSiblingDB("admin")admin.createUser({user:“clusteradmin”,pwd:“clusterpwd”,roles:[{role:"userAdminAnyDatabase",db:"admin"},{role:“clusterAdmin”,db:"admin"},{role:“root”,db:"admin"}]})

测试用户：

db.getSiblingDB("admin").auth(“clusteradmin”,“clusterpwd”)


在各从节点上关闭服务：

use admin

db.shutdownServer()

包括arbiter节点也要关闭服务，最后再关闭primary节点的服务。

在各配置文件mongod.conf文件中添加auth相关的文件，配置如下所示：

security:keyFile:/data/mongodb/conf/keyfile.key[root@mongo01~]#cat/data/mongodb/conf/keyfile.keyabcdefgh该文件的权限必须是600或400，并把该文件复制到各节点上（保持内容相同），该文件也可以使用以下命令生成：opensslrand-base64755>path-to-keyfile

最后再新启动各节点的mongodb服务，并重新login ，测试。


参考：

https://docs.mongodb.com/manual/tutorial/deploy-replica-set/

https://docs.mongodb.com/manual/tutorial/enforce-keyfile-access-control-in-existing-replica-set/



四、补充 CentOS7上部署mongodb 3.6的 RS

(1) 在vm2主机上配置mongod如下所示：

[root@vm2~]#mkdir-p/data/mongodb/{conf,run,logs,data}[root@vm2~]#chown-Rmongod.mongod/data/mongodb[root@vm2~]#vim/etc/mongod.conf[root@vm2~]#grep-Pv"^(#|$)"/etc/mongod.confsystemLog:destination:filelogAppend:truepath:/data/mongodb/logs/mongod.logstorage:dbPath:/data/mongodb/data/directoryPerDB:truejournal:enabled:trueprocessManagement:fork:true#forkandruninbackgroundpidFilePath:/data/mongodb/run/mongod.pid#locationofpidfiletimeZoneInfo:/usr/share/zoneinfonet:port:27027bindIp:0.0.0.0#Listentolocalinterfaceonly,commenttolistenonallinterfaces.security:authorization:enabledkeyFile:/data/mongodb/conf/keyFilereplication:replSetName:rs0[root@vm2~]#注：必须保证mongod.conf文件与mongod.service文件中的各路径设置一致，否则会导致启动失败[root@vm2~]#cd/usr/lib/systemd/system/[root@vm2system]#head-15mongod.service[Unit]Description=High-performance,schema-freedocument-orienteddatabaseAfter=network.targetDocumentation=https://docs.mongodb.org/manual[Service]User=mongodGroup=mongodEnvironment="OPTIONS=-f/etc/mongod.conf"ExecStart=/usr/bin/mongod$OPTIONSExecStartPre=/usr/bin/mkdir-p/data/mongodb/runExecStartPre=/usr/bin/chownmongod:mongod/data/mongodb/runExecStartPre=/usr/bin/chmod0755/data/mongodb/runPermissionsStartOnly=truePIDFile=/data/mongodb/run/mongod.pid[root@vm2system]#[root@vm2~]#opensslrand-base64755>/data/mongodb/conf/keyFile[root@vm2~]#chownmongod.mongod/data/mongodb/conf/keyFile[root@vm2~]#chmod400/data/mongodb/conf/keyFile

（2）在vm2主机上配置arbiter 如下所示：

[root@vm2data]#mkdirarbiter/{conf,data,logs,run}-p[root@vm2data]#cpmongodb/conf/keyFilearbiter/conf/[root@vm2data]#chmod400/data/arbiter/conf/[root@vm2data]#cp/etc/mongod.confarbiter/conf/[root@vm2data]#mvconf/mongod.confconf/arbiter.conf[root@vm2data]#vimarbiter/conf/arbiter.conf[root@vm2data]#chown-Rmongod.mongodarbiter[root@vm2data]#grep-Pv"^(#|$)"arbiter/conf/arbiter.confsystemLog:destination:filelogAppend:truepath:/data/arbiter/logs/arbiter.logstorage:dbPath:/data/arbiter/data/directoryPerDB:truejournal:enabled:trueprocessManagement:fork:true#forkandruninbackgroundpidFilePath:/data/arbiter/run/arbiter.pid#locationofpidfiletimeZoneInfo:/usr/share/zoneinfonet:port:37027bindIp:0.0.0.0#Listentolocalinterfaceonly,commenttolistenonallinterfaces.security:authorization:enabledkeyFile:/data/arbiter/conf/keyFilereplication:replSetName:rs0[root@vm2data]#[root@vm2data]#cd/usr/lib/systemd/system[root@vm2system]#cpmongod.servicearbiter.service[root@vm2system]#vimarbiter.service[root@vm2system]#head-15arbiter.service[Unit]Description=High-performance,schema-freedocument-orienteddatabaseAfter=network.targetDocumentation=https://docs.mongodb.org/manual[Service]User=mongodGroup=mongodEnvironment="OPTIONS=-f/data/arbiter/conf/arbiter.conf"ExecStart=/usr/bin/mongod$OPTIONSExecStartPre=/usr/bin/mkdir-p/data/arbiter/runExecStartPre=/usr/bin/chownmongod:mongod/data/arbiter/runExecStartPre=/usr/bin/chmod0755/data/arbiter/runPermissionsStartOnly=truePIDFile=/data/arbiter/run/arbiter.pid[root@vm2system]#[root@vm2system]#systemctldaemon-reload[root@vm2arbiter]#tree.├──conf│├──arbiter.conf│└──keyFile├──data├──logs└──run4directories,2files[root@vm2arbiter]#[root@vm2data]#echonever>/sys/kernel/mm/transparent_hugepage/enabled[root@vm2data]#systemctlrestartmongod[root@vm2data]#systemctlrestartarbiter[root@vm2data]#ps-ef|grepmongodmongod1302561812:46?00:00:01/usr/bin/mongod-f/etc/mongod.confmongod13035411412:46?00:00:01/usr/bin/mongod-f/data/arbiter/conf/arbiter.confroot130387125564012:46pts/000:00:00grep--color=automongod[root@vm2data]#

（3）在另一台mongodb server上安装并配置mongodb，配置内容与vm2上完全相同。然后添加rs，操作如下：

[root@meteor~]#cat/sys/kernel/mm/transparent_hugepage/enabled[always]madvisenever[root@meteor~]#echonever>/sys/kernel/mm/transparent_hugepage/enabled[root@meteor~]#systemctlrestartmongod[root@meteor~]#mongolocalhost:27027/admin-uroot-pMongoDBshellversionv3.6.5Enterpassword:connectingto:mongodb://localhost:27027/adminMongoDBserverversion:3.6.5>showdbs2018-05-26T20:41:42.392+0800EQUERY[thread1]Error:listDatabasesfailed:{"ok":0,"errmsg":"notmasterandslaveOk=false","code":13435,"codeName":"NotMasterNoSlaveOk"}:_getErrorWithCode@src/mongo/shell/utils.js:25:13Mongo.prototype.getDBs@src/mongo/shell/mongo.js:65:1shellHelper.show@src/mongo/shell/utils.js:849:19shellHelper@src/mongo/shell/utils.js:739:15@(shellhelp2):1:1>rs.slaveOk()>rs.status(){"info":"runrs.initiate(...)ifnotyetdonefortheset","ok":0,"errmsg":"noreplsetconfighasbeenreceived","code":94,"codeName":"NotYetInitialized"}>config={"_id":"rs0","members":[...{"_id":0,"host":"192.168.20.221:27027","priority":100},...{"_id":1,"host":"192.168.40.206:27027","priority":1},...{"_id":2,"host":"192.168.40.206:37027","priority":0,"arbiterOnly":true}...]}{"_id":"rs0","members":[{"_id":0,"host":"192.168.20.221:27027","priority":100},{"_id":1,"host":"192.168.40.206:27027","priority":1},{"_id":2,"host":"192.168.40.206:37027","priority":0,"arbiterOnly":true}]}>rs.initiate(config){"ok":1}rs0:SECONDARY>rs0:SECONDARY>rs0:PRIMARY>rs0:PRIMARY>rs.status(){"set":"rs0","date":ISODate("2018-05-26T12:49:29.987Z"),"myState":1,"term":NumberLong(1),"heartbeatIntervalMillis":NumberLong(2000),"optimes":{"lastCommittedOpTime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"readConcernMajorityOpTime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"appliedOpTime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"durableOpTime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)}},"members":[{"_id":0,"name":"192.168.20.221:27027","health":1,"state":1,"stateStr":"PRIMARY","uptime":503,"optime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"optimeDate":ISODate("2018-05-26T12:49:23Z"),"infoMessage":"couldnotfindmembertosyncfrom","electionTime":Timestamp(1527338942,1),"electionDate":ISODate("2018-05-26T12:49:02Z"),"configVersion":1,"self":true},{"_id":1,"name":"192.168.40.206:27027","health":1,"state":2,"stateStr":"SECONDARY","uptime":38,"optime":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"optimeDurable":{"ts":Timestamp(1527338963,1),"t":NumberLong(1)},"optimeDate":ISODate("2018-05-26T12:49:23Z"),"optimeDurableDate":ISODate("2018-05-26T12:49:23Z"),"lastHeartbeat":ISODate("2018-05-26T12:49:28.268Z"),"lastHeartbeatRecv":ISODate("2018-05-26T12:49:28.274Z"),"pingMs":NumberLong(1),"syncingTo":"192.168.20.221:27027","configVersion":1},{"_id":2,"name":"192.168.40.206:37027","health":1,"state":7,"stateStr":"ARBITER","uptime":38,"lastHeartbeat":ISODate("2018-05-26T12:49:28.266Z"),"lastHeartbeatRecv":ISODate("2018-05-26T12:49:29.107Z"),"pingMs":NumberLong(1),"configVersion":1}],"ok":1,"operationTime":Timestamp(1527338963,1),"$clusterTime":{"clusterTime":Timestamp(1527338963,1),"signature":{"hash":BinData(0,"xxW1WBNE99FOs8BNdAanWKOhFUk="),"keyId":NumberLong("6559870810092208129")}}}rs0:PRIMARY>

（4）在secondary节点上登录，并查看状态，验证数据一致性。

说明：

priority：表示一个成员被选举为Primary节点的优先级，默认值是1，取值范围是从0到100，将priority设置为0有特殊含义：Priority为0的成员永远不能成为Primary 节点。Replica Set中，Priority最高的成员，会优先被选举为Primary 节点，只要其满足条件。
hidden：将成员配置为隐藏成员，要求Priority 为0。Client不会向隐藏成员发送请求，因此隐藏成员不会收到Client的Request。
slaveDelay：单位是秒，将Secondary 成员配置为延迟备份节点，要求Priority 为0，表示该成员比Primary 成员滞后指定的时间，才能将Primary上进行的写操作同步到本地。为了数据读取的一致性，应将延迟备份节点的hidden设置为true，避免用户读取到明显滞后的数据。Delayed members maintain a copy of the data that reflects the state of the data at some time in the past.
votes：有效值是0或1，默认值是1，如果votes是1，表示该成员（voting member）有权限选举Primary 成员。在一个Replica Set中，最多有7个成员，其votes 属性的值是1。
arbiterOnly：表示该成员是仲裁者，arbiter的唯一作用是就是参与选举，其votes属性是1，arbiter不保存数据，也不会为client提供服务。

总结：本内容前半部分是使用rs.add("....")的方法添加副本集，而后半部分是使用 先定义config ，然后再 rs.initiate(config)的方法 添加副本集。各位朋友可根据需要各自选用不同的方法