Mongodb副本集添加節(jié)點,你學(xué)會了嗎?
1、準(zhǔn)備工作
有一套mongodb 副本集的集群,部署方式參考 mongodb 4.0副本集搭建。
準(zhǔn)備一個新節(jié)點,使用和原副本集版本一致的mongodb。
拷貝原副本集中的配置文件、keyfile文件,并注意修改keyfile文件的權(quán)限(600)。
節(jié)點 | 角色 |
192.168.56.199:27017 | PRIMARY |
192.168.56.198:27018 | SECONDARY |
192.168.56.199:27018 | ARBITER |
準(zhǔn)備加入的新節(jié)點: 192.168.56.197:27017。
2、添加節(jié)點
(1)啟動新節(jié)點
例如,原節(jié)點的版本是4.2.8,新節(jié)點版本一致,路徑一致,然后啟動新節(jié)點。
/usr/local/mongodb/bin/mongod -f /data/mongodb/27017/etc/mongodb.conf
(2)主庫上查看當(dāng)前節(jié)點及配置信息
使用rs.config()查看配置信息。
test12:PRIMARY> rs.config()
{
"_id" : "test12",
"version" : 1,
"protocolVersion" : NumberLong(1),
"writeConcernMajorityJournalDefault" : true,
"members" : [
{
"_id" : 0,
"host" : "192.168.56.198:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.56.199:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.56.199:27018",
"arbiterOnly" : true,
"buildIndexes" : true,
"hidden" : false,
"priority" : 0,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : -1,
"catchUpTakeoverDelayMillis" : 30000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("61b86af0a21015e69623e18d")
}
}
rs.status() 查看狀態(tài)信息。
test12:PRIMARY> rs.status()
{
"set" : "test12",
"date" : ISODate("2021-12-14T10:07:46.561Z"),
"myState" : 1,
"term" : NumberLong(1),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"heartbeatIntervalMillis" : NumberLong(2000),
"majorityVoteCount" : 2,
"writeMajorityCount" : 2,
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"lastCommittedWallTime" : ISODate("2021-12-14T10:07:42.560Z"),
"readConcernMajorityOpTime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"readConcernMajorityWallTime" : ISODate("2021-12-14T10:07:42.560Z"),
"appliedOpTime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"durableOpTime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"lastAppliedWallTime" : ISODate("2021-12-14T10:07:42.560Z"),
"lastDurableWallTime" : ISODate("2021-12-14T10:07:42.560Z")
},
"lastStableRecoveryTimestamp" : Timestamp(1639476442, 1),
"lastStableCheckpointTimestamp" : Timestamp(1639476442, 1),
"electionCandidateMetrics" : {
"lastElectionReason" : "electionTimeout",
"lastElectionDate" : ISODate("2021-12-14T09:59:22.407Z"),
"electionTerm" : NumberLong(1),
"lastCommittedOpTimeAtElection" : {
"ts" : Timestamp(0, 0),
"t" : NumberLong(-1)
},
"lastSeenOpTimeAtElection" : {
"ts" : Timestamp(1639475952, 1),
"t" : NumberLong(-1)
},
"numVotesNeeded" : 2,
"priorityAtElection" : 1,
"electionTimeoutMillis" : NumberLong(10000),
"numCatchUpOps" : NumberLong(0),
"newTermStartDate" : ISODate("2021-12-14T09:59:22.431Z"),
"wMajorityWriteAvailabilityDate" : ISODate("2021-12-14T09:59:23.493Z")
},
"members" : [
{
"_id" : 0,
"name" : "192.168.56.198:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 514,
"optime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"optimeDurable" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2021-12-14T10:07:42Z"),
"optimeDurableDate" : ISODate("2021-12-14T10:07:42Z"),
"lastHeartbeat" : ISODate("2021-12-14T10:07:45.153Z"),
"lastHeartbeatRecv" : ISODate("2021-12-14T10:07:46.542Z"),
"pingMs" : NumberLong(1),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.56.199:27017",
"syncSourceHost" : "192.168.56.199:27017",
"syncSourceId" : 1,
"infoMessage" : "",
"configVersion" : 1
},
{
"_id" : 1,
"name" : "192.168.56.199:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 1001,
"optime" : {
"ts" : Timestamp(1639476462, 1),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2021-12-14T10:07:42Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"electionTime" : Timestamp(1639475962, 1),
"electionDate" : ISODate("2021-12-14T09:59:22Z"),
"configVersion" : 1,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 2,
"name" : "192.168.56.199:27018",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 514,
"lastHeartbeat" : ISODate("2021-12-14T10:07:44.896Z"),
"lastHeartbeatRecv" : ISODate("2021-12-14T10:07:44.896Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"configVersion" : 1
}
],
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1639476462, 1),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
},
"operationTime" : Timestamp(1639476462, 1)
}
(3)將新節(jié)點添加至集群
在主庫上執(zhí)行rs.add()將新節(jié)點添加進集群中.
生產(chǎn)環(huán)境添加節(jié)點時,建議將priority及votes設(shè)為0,即不會選為主(priority默認1),也沒有投票特性(votes默認1,有投票權(quán))。
test12:PRIMARY> rs.add( { host: "192.168.56.197:27017", priority: 0, votes: 0 } )
{
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1639476997, 1),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
},
"operationTime" : Timestamp(1639476997, 1)
}
另外,生產(chǎn)環(huán)境是從主庫拉取全量數(shù)據(jù),如果數(shù)據(jù)量較大,則需要觀察主庫的壓力及對線上業(yè)務(wù)的影響。
同步數(shù)據(jù)的過程中,新節(jié)點的狀態(tài)stateStr 為STARTUP2,待同步完成后會變?yōu)镾ECONDARY。
(4)重置新節(jié)點的屬性
此時再用rs.config()查看新節(jié)點狀態(tài),priority及votes是之前設(shè)的0,可以使用 rs.recofig()命令進行調(diào)整
test12:PRIMARY> rs.config()
{
"_id" : "test12",
"version" : 2,
"protocolVersion" : NumberLong(1),
"writeConcernMajorityJournalDefault" : true,
"members" : [
{
"_id" : 0,
"host" : "192.168.56.198:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.56.199:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.56.199:27018",
"arbiterOnly" : true,
"buildIndexes" : true,
"hidden" : false,
"priority" : 0,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 3,
"host" : "192.168.56.197:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 0,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 0
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : -1,
"catchUpTakeoverDelayMillis" : 30000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("61b86af0a21015e69623e18d")
}
}
從上面可以看到新節(jié)點的id為3 ,則可以通過如下命令調(diào)整對應(yīng)的屬性。
var cfg = rs.conf()
cfg.members[3].priority = 1
cfg.members[3].votes = 1
rs.reconfig(cfg)
調(diào)整后再查看,屬性已調(diào)整。
test12:PRIMARY> rs.config()
{
"_id" : "test12",
"version" : 3,
"protocolVersion" : NumberLong(1),
"writeConcernMajorityJournalDefault" : true,
"members" : [
{
"_id" : 0,
"host" : "192.168.56.198:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.56.199:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.56.199:27018",
"arbiterOnly" : true,
"buildIndexes" : true,
"hidden" : false,
"priority" : 0,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 3,
"host" : "192.168.56.197:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : -1,
"catchUpTakeoverDelayMillis" : 30000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("61b86af0a21015e69623e18d")
}
}
至此,新節(jié)點便加入了副本集中。
3、注意點總結(jié)
- 一個副本集,最多可以擁有50個secondary,最多可以有7個投票成員,在副本集里面添加一個新成員,如果之前副本集已經(jīng)有了7個成員,那么可以設(shè)置成非投票成員,或者你從移除之前一個投票成員出來。
- 新節(jié)點的版本、配置建議與原集群一致。
- 注意添加新節(jié)點前確定網(wǎng)絡(luò)互通。
- 如果集群數(shù)據(jù)量較大,則選擇業(yè)務(wù)低峰期添加節(jié)點,并觀察壓力情況。
- 新節(jié)點加入時建議將priority及votes設(shè)為0。