MongoDB複製集之將現有的單節點服務器轉換爲複製集

服務器狀況:

  現有的單節點 Primary     192.168.126.9:27017

  新增的節點    Secondry  192.168.126.8:27017

   仲裁節點      ARBITER   192.168.126.8:27018

    mongo 版本 3.2.4

 

1.中止單節點Primary的Mongo服務 

1 > use admin;  
2 switched to db admin  
3 > db.shutdownServer() 

2.從新啓動Primary節點,使用--replSet的選項加上新複製集的名字 repl1

 /usr/local/mongodb/bin/mongod -dbpath /sdb1/mongodb/data --fork --port 27017 --logpath /sdb1/mongodb/log/mongo.log --replSet repl1 --logappend 

3.鏈接Primary數據庫

4. 建立複製集配置信息對象

1 config = { _id:"repl1", members:[
2                      {_id:0,host:"192.168.126.9:27017"}
3                 ]
4          }

5.初始化複製集並查看複製集的運行狀態

 1 > rs.initiate(config)
 2 { "ok" : 1 }
 3 
 4 repl1:SECONDARY> rs.status()
 5 {
 6         "set" : "repl1",
 7         "date" : ISODate("2016-06-23T16:05:10.228Z"),
 8         "myState" : 1,
 9         "term" : NumberLong(1),
10         "heartbeatIntervalMillis" : NumberLong(2000),
11         "members" : [
12                 {
13                         "_id" : 0,
14                         "name" : "192.168.126.9:27017",
15                         "health" : 1,
16                         "state" : 1,
17                         "stateStr" : "PRIMARY",
18                         "uptime" : 3524,
19                         "optime" : {
20                                 "ts" : Timestamp(1466697870, 1),
21                                 "t" : NumberLong(1)
22                         },
23                         "optimeDate" : ISODate("2016-06-23T16:04:30Z"),
24                         "infoMessage" : "could not find member to sync from",
25                         "electionTime" : Timestamp(1466697868, 2),
26                         "electionDate" : ISODate("2016-06-23T16:04:28Z"),
27                         "configVersion" : 1,
28                         "self" : true
29                 }
30         ],
31         "ok" : 1

 

6.啓動 Secondry Mongo節點服務

root@linux-mongo2:/home/ubuntu# /usr/local/mongodb/bin/mongod -dbpath=/sdb1/mongodb/data --fork --port 27017 --logpath=/sdb1/mongodb/log/mongo.log --logappend --replSet repl1

about to fork child process, waiting until server is ready for connections. forked process: 2848 child process started successfully, parent exiting

7.在Primary節點將 Secondry Mongo節點添加到複製集裏

repl1:PRIMARY> rs.add("192.168.126.8:27017")
{ "ok" : 1 }

8.啓動 ARBITER Mongo仲裁節點

root@linux-mongo2:/home/ubuntu# mkdir -p /sdb1/mongodb/arb
root@linux-mongo2:/home/ubuntu# /usr/local/mongodb/bin/mongod -dbpath=/sdb1/mongodb/arb --fork --port 27018 --logpath=/sdb1/mongodb/arb/mongo.log --logappend --relpSet replSet repl1
Error parsing command line: unrecognised option '--relpSet'
try '/usr/local/mongodb/bin/mongod --help' for more information
root@linux-mongo2:/home/ubuntu# /usr/local/mongodb/bin/mongod -dbpath=/sdb1/mongodb/arb --fork --port 27018 --logpath=/sdb1/mongodb/arb/mongo.log --logappend -replSet repl1
about to fork child process, waiting until server is ready for connections.
forked process: 3229
child process started successfully, parent exiting

9.在主節點將仲裁節點添加在複製集中,並查看最終的複製集狀態

 1 repl1:PRIMARY> rs.addArb("192.168.126.8:27018")
 2 { "ok" : 1 }
 3 
 4 repl1:PRIMARY> rs.status()
 5 {
 6         "set" : "repl1",
 7         "date" : ISODate("2016-06-23T16:27:55.358Z"),
 8         "myState" : 1,
 9         "term" : NumberLong(1),
10         "heartbeatIntervalMillis" : NumberLong(2000),
11         "members" : [
12                 {
13                         "_id" : 0,
14                         "name" : "192.168.126.9:27017",
15                         "health" : 1,
16                         "state" : 1,
17                         "stateStr" : "PRIMARY",
18                         "uptime" : 4889,
19                         "optime" : {
20                                 "ts" : Timestamp(1466699268, 1),
21                                 "t" : NumberLong(1)
22                         },
23                         "optimeDate" : ISODate("2016-06-23T16:27:48Z"),
24                         "electionTime" : Timestamp(1466697868, 2),
25                         "electionDate" : ISODate("2016-06-23T16:04:28Z"),
26                         "configVersion" : 3,
27                         "self" : true
28                 },
29                 {
30                         "_id" : 1,
31                         "name" : "192.168.126.8:27017",
32                         "health" : 1,
33                         "state" : 5,
34                         "stateStr" : "STARTUP2",
35                         "uptime" : 1005,
36                         "optime" : {
37                                 "ts" : Timestamp(0, 0),
38                                 "t" : NumberLong(-1)
39                         },
40                         "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
41                         "lastHeartbeat" : ISODate("2016-06-23T16:27:54.499Z"),
42                         "lastHeartbeatRecv" : ISODate("2016-06-23T16:27:54.561Z"),
43                         "pingMs" : NumberLong(0),
44                         "syncingTo" : "192.168.126.9:27017",
45                         "configVersion" : 3
46                 },
47                 {
48                         "_id" : 2,
49                         "name" : "192.168.126.8:27018",
50                         "health" : 1,
51                         "state" : 7,
52                         "stateStr" : "ARBITER",
53                         "uptime" : 6,
54                         "lastHeartbeat" : ISODate("2016-06-23T16:27:54.499Z"),
55                         "lastHeartbeatRecv" : ISODate("2016-06-23T16:27:53.632Z"),
56                         "pingMs" : NumberLong(1),
57                         "configVersion" : 3
58                 }
59         ],
60         "ok" : 1
61 }

注意: 這裏副本集 192.168.126.8 的狀態是 "STARTUP2" ,是因爲Primary庫的數據很大,致使一直處於初始化的同步數據階段。 

詳細說明以下 

"_id" :  #集羣中節點編號
"name" :  #成員服務器名稱及端口
"health" :  #表示成員中的健康狀態（0:down;1:up）
"state" :  #爲1~11，表示成員的當前狀態
"stateStr" :  #描述該成員是主庫（PRIMARY）仍是備庫（SECONDARY）
"uptime" :  #該成員在線時間（秒）
"optime" :  #成員最後一次應用日誌(oplog)的信息
"optimeDate" :  #成員最後一次應用日誌(oplog)的時間
"electionTime" :  #當前primary從操做日誌中選舉信息
"electionDate" :  #當前primary被選定爲primary的日期
"configVersion" :  #mongodb版本
"self" :  #爲true 表示當前節點其中 state 複製集狀態:複製集狀態：  STARTUP：剛加入到複製集中，配置還未加載  STARTUP2：配置已加載完，初始化狀態  RECOVERING：正在恢復，不適用讀  ARBITER: 仲裁者  DOWN：節點不可到達  UNKNOWN：未獲取其餘節點狀態而不知是什麼狀態，通常發生在只有兩個成員的架構，腦裂  REMOVED：移除複製集  ROLLBACK：數據回滾，在回滾結束時，轉移到RECOVERING或SECONDARY狀態  FATAL：出錯。查看日誌grep "replSet FATAL"找出錯緣由，從新作同步  PRIMARY：主節點  SECONDARY：備份節點