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May 31, 2013
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MongoDB 副本集自动复制 Replica Set

MongoDB部署实验系列文章，MongoDB做为NoSQL数据库，最近几年持续升温，越来越多的企业都开始尝试用MongoDB代替原有Database做一些事情。MongoDB也在集群，分片，复制上也有相当不错的的表现。我通过将做各种MongoDB的部署实验进行介绍。

关于作者：

  • 张丹(Conan), 程序员Java,R,PHP,Javascript
  • weibo：@Conan_Z
  • blog: http://blog.fens.me
  • email: bsspirit@gmail.com

转载请注明：
http://blog.fens.me/mongodb-replica-set/

rs

第二篇 MongoDB 副本集自动复制 Replica Set，分为7个部分

  1. 初始化文件目录
  2. 启动副本集 Replica Set
  3. 模拟 PRIMARY失败，SECONDARY自动切换
  4. 修复失败节点
  5. 恢复失败节点，补充到SECONDARY
  6. 删除一个Replica Set节点
  7. 新增加一个Replica Set节点

系统环境介绍：

Ubuntu 12.04. LTS 64bit Server

 

初始化文件目录

~ pwd
/home/conan/dbs

~ mkdir node1 node2 node3
~ ls -l
drwxrwxr-x 2 conan conan 4096 May 31 14:21 node1
drwxrwxr-x 2 conan conan 4096 May 31 14:21 node2
drwxrwxr-x 2 conan conan 4096 May 31 14:21 node3

 

启动副本集 Replica Set

启动node1,node2,node3

mongod --dbpath /home/conan/dbs/node1 --port 10001 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node1.log
mongod --dbpath /home/conan/dbs/node2 --port 10002 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node2.log
mongod --dbpath /home/conan/dbs/node3 --port 10003 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node3.log

副本集初始化

~ mongo localhost:10001
MongoDB shell version: 2.4.3
connecting to: localhost:10001/test
> rs.initiate({_id:"blort",members:[
{_id:1,host:"localhost:10001"},
{_id:2,host:"localhost:10002"},
{_id:3,host:"localhost:10003"},
]})
{
"info" : "Config now saved locally. Should come online in about a minute.",
"ok" : 1
}

查看日志信息:node1变选为PRIMARY,node2,node3分别是2个SECONDARY

Fri May 31 14:26:44.728 [conn2] ******
Fri May 31 14:26:44.728 [conn2] replSet info saving a newer config version to local.system.replset
Fri May 31 14:26:44.741 [conn2] replSet saveConfigLocally done
Fri May 31 14:26:44.741 [conn2] replSet replSetInitiate config now saved locally. Should come online in about a minute.
Fri May 31 14:26:44.741 [conn2] command admin.$cmd command: { replSetInitiate: { _id: "blort", members: [ { _id: 1.0, host: "localhost:10001" }, { _id: 2.0, host: "localhost:10002" }, { _id: 3.0, host: "localhost:10003" } ] } } ntoreturn:1 keyUpdates:0 locks(micros) W:646741 reslen:112 652ms
Fri May 31 14:26:53.682 [rsStart] replSet I am localhost:10001
Fri May 31 14:26:53.682 [rsStart] replSet STARTUP2
Fri May 31 14:26:53.683 [rsHealthPoll] replSet member localhost:10002 is up
Fri May 31 14:26:53.684 [rsHealthPoll] replSet member localhost:10003 is up
Fri May 31 14:26:54.285 [initandlisten] connection accepted from 127.0.0.1:46469 #3 (3 connections now open)
Fri May 31 14:26:54.683 [rsSync] replSet SECONDARY

用mongo客户端查看设置
node1连接

~ mongo localhost:10001
MongoDB shell version: 2.4.3
connecting to: localhost:10001/test
blort:PRIMARY> rs.status()
{
"set" : "blort",
"date" : ISODate("2013-05-31T06:34:12Z"),
"myState" : 1,
"members" : [
{
"_id" : 1,
"name" : "localhost:10001",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 659,
"optime" : {
"t" : 1369981604,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T06:26:44Z"),
"self" : true
},
{
"_id" : 2,
"name" : "localhost:10002",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 439,
"optime" : {
"t" : 1369981604,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T06:26:44Z"),
"lastHeartbeat" : ISODate("2013-05-31T06:34:11Z"),
"lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
"pingMs" : 0,
"syncingTo" : "localhost:10001"
},
{
"_id" : 3,
"name" : "localhost:10003",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 439,
"optime" : {
"t" : 1369981604,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T06:26:44Z"),
"lastHeartbeat" : ISODate("2013-05-31T06:34:11Z"),
"lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
"pingMs" : 0,
"syncingTo" : "localhost:10001"
}
],
"ok" : 1
}

node2连接

~ mongo localhost:10002
MongoDB shell version: 2.4.3
connecting to: localhost:10002/test
blort:SECONDARY>

在primary插入数据：

~ mongo localhost:10001
MongoDB shell version: 2.4.3
connecting to: localhost:10001/test

blort:PRIMARY> show dbs
local 1.078125GB

blort:PRIMARY> use fensme
switched to db fensme

blort:PRIMARY> db.user.insert({uid:10001})
blort:PRIMARY> db.user.find()
{ “_id” : ObjectId(“51a8454813321f05df62a8c8”), “uid” : 10001 }

连接node2，SECONDARY查询数据

~ mongo localhost:10002
MongoDB shell version: 2.4.3
connecting to: localhost:10002/test

blort:SECONDARY> show dbs
fensme 0.203125GB
local 1.078125GB

blort:SECONDARY> use fensme
switched to db fensme

blort:SECONDARY> show collections
Fri May 31 14:39:22.276 JavaScript execution failed: error: { “$err” : “not master and slaveOk=false”, “code” : 13435 } at src/mongo/shell/query.js:L128

blort:SECONDARY> db.user.find()
error: { “$err” : “not master and slaveOk=false”, “code” : 13435 }

提示是不是master/slave的结构，SECONDARY不许允查询。

模拟 PRIMARY失败，SECONDARY自动切换


ps -aux|grep mongod
conan 5110 0.4 2.1 1723616 44608 ? Sl 14:23 0:05 mongod --dbpath /home/conan/dbs/node1 --port 10001 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node1.log
conan 5173 0.4 2.2 1693812 45960 ? Sl 14:24 0:04 mongod --dbpath /home/conan/dbs/node2 --port 10002 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node2.log
conan 5218 0.4 2.2 1692800 45548 ? Sl 14:24 0:04 mongod --dbpath /home/conan/dbs/node3 --port 10003 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node3.log


kill -9 5110
ps -aux|grep mongod
conan 5173 0.4 2.2 1703048 46096 ? Sl 14:24 0:04 mongod --dbpath /home/conan/dbs/node2 --port 10002 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node2.log
conan 5218 0.4 2.2 1702036 45696 ? Sl 14:24 0:04 mongod --dbpath /home/conan/dbs/node3 --port 10003 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node3.log

连接node2，SECONDARY查询节点重新选举

~ mongo localhost:10002
MongoDB shell version: 2.4.3
connecting to: localhost:10002/test

blort:SECONDARY> rs.status()
{
“set” : “blort”,
“date” : ISODate(“2013-05-31T06:42:51Z”),
“myState” : 2,
“syncingTo” : “localhost:10003”,
“members” : [
{
“_id” : 1,
“name” : “localhost:10001”,
“health” : 0,
“state” : 8,
“stateStr” : “(not reachable/healthy)”,
“uptime” : 0,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“lastHeartbeat” : ISODate(“2013-05-31T06:42:51Z”),
“lastHeartbeatRecv” : ISODate(“1970-01-01T00:00:00Z”),
“pingMs” : 0
},
{
“_id” : 2,
“name” : “localhost:10002”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 1088,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“errmsg” : “syncing to: localhost:10003”,
“self” : true
},
{
“_id” : 3,
“name” : “localhost:10003”,
“health” : 1,
“state” : 1,
“stateStr” : “PRIMARY”,
“uptime” : 946,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“lastHeartbeat” : ISODate(“2013-05-31T06:42:51Z”),
“lastHeartbeatRecv” : ISODate(“1970-01-01T00:00:00Z”),
“pingMs” : 0,
“syncingTo” : “localhost:10001”
}
],
“ok” : 1
}

查看结果：

  • localhost:10001 ： not reachable/healthy
  • localhost:10002： SECONDARY
  • localhost:10003： PRIMARY

连接node3, localhost:10003查看数据

mongo localhost:10003
MongoDB shell version: 2.4.3
connecting to: localhost:10003/test

blort:PRIMARY> show dbs
fensme 0.203125GB
local 1.078125GB

blort:PRIMARY> use fensme
switched to db fensme

blort:PRIMARY> show collections
system.indexes
user

blort:PRIMARY> db.user.find()
{ “_id” : ObjectId(“51a8454813321f05df62a8c8”), “uid” : 10001 }

node1失效后，node3被选为了PRIMARY，数据在node3可以查询到。

修复失败节点

直接重启node1，启动失败：

~ mongod --dbpath /home/conan/dbs/node1 --port 10001 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node1_restart.log
MongoDB starting : pid=8544 port=10001 dbpath=/home/conan/dbs/node1 64-bit host=u1
Fri May 31 14:49:37.280 [initandlisten] db version v2.4.3
Fri May 31 14:49:37.280 [initandlisten] git version: fe1743177a5ea03e91e0052fb5e2cb2945f6d95f
Fri May 31 14:49:37.280 [initandlisten] build info: Linux ip-10-2-29-40 2.6.21.7-2.ec2.v1.2.fc8xen #1 SMP Fri Nov 20 17:48:28 EST 2009 x86_64 BOOST_LIB_VERSION=1_49
Fri May 31 14:49:37.280 [initandlisten] allocator: tcmalloc
Fri May 31 14:49:37.280 [initandlisten] options: { dbpath: "/home/conan/dbs/node1", fork: true, logpath: "/home/conan/dbs/node1_restart.log", nojournal: true, port: 10001, replSet: "blort" }
**************
Unclean shutdown detected.
Please visit http://dochub.mongodb.org/core/repair for recovery instructions.
*************
Fri May 31 14:49:37.281 [initandlisten] exception in initAndListen: 12596 old lock file, terminating
Fri May 31 14:49:37.281 dbexit:
Fri May 31 14:49:37.281 [initandlisten] shutdown: going to close listening sockets...
Fri May 31 14:49:37.281 [initandlisten] shutdown: going to flush diaglog...
Fri May 31 14:49:37.281 [initandlisten] shutdown: going to close sockets...
Fri May 31 14:49:37.281 [initandlisten] shutdown: waiting for fs preallocator...
Fri May 31 14:49:37.281 [initandlisten] shutdown: closing all files...
Fri May 31 14:49:37.281 [initandlisten] closeAllFiles() finished
Fri May 31 14:49:37.281 dbexit: really exiting now

5. 恢复失败节点，补充到SECONDARY


mkdir /home/conan/dbs/repair/
mongod --dbpath /home/conan/dbs/node1 --port 10001 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node1_restart_repair.log --repairpath /home/conan/dbs/repair/
about to fork child process, waiting until server is ready for connections.
forked process: 13736
all output going to: /home/conan/dbs/node1_restart_repair.log
child process started successfully, parent exiting

修复成功。

重新连接node1，查看节点状态

~ mongo localhost:10001
MongoDB shell version: 2.4.3
connecting to: localhost:10001/test

blort:SECONDARY> rs.status()
{
“set” : “blort”,
“date” : ISODate(“2013-05-31T07:04:34Z”),
“myState” : 2,
“syncingTo” : “localhost:10003”,
“members” : [
{
“_id” : 1,
“name” : “localhost:10001”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 74,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“errmsg” : “syncing to: localhost:10003”,
“self” : true
},
{
“_id” : 2,
“name” : “localhost:10002”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 74,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“lastHeartbeat” : ISODate(“2013-05-31T07:04:33Z”),
“lastHeartbeatRecv” : ISODate(“1970-01-01T00:00:00Z”),
“pingMs” : 0,
“syncingTo” : “localhost:10003”
},
{
“_id” : 3,
“name” : “localhost:10003”,
“health” : 1,
“state” : 1,
“stateStr” : “PRIMARY”,
“uptime” : 74,
“optime” : {
“t” : 1369982280,
“i” : 1
},
“optimeDate” : ISODate(“2013-05-31T06:38:00Z”),
“lastHeartbeat” : ISODate(“2013-05-31T07:04:33Z”),
“lastHeartbeatRecv” : ISODate(“2013-05-31T07:04:34Z”),
“pingMs” : 0
}
],
“ok” : 1
}

查看结果：

  • localhost:10001： SECONDARY
  • localhost:10002： SECONDARY
  • localhost:10003： PRIMARY

node1节点已恢复。

6. 删除一个Replica Set节点

删除node1

blort:PRIMARY> rs.remove("localhost:10001")
Fri May 31 15:40:21.977 DBClientCursor::init call() failed
Fri May 31 15:40:21.978 JavaScript execution failed: Error: error doing query: failed at src/mongo/shell/query.js:L78
Fri May 31 15:40:21.979 trying reconnect to localhost:10003
Fri May 31 15:40:21.980 reconnect localhost:10003 ok
rs.status()
{
"set" : "blort",
"date" : ISODate("2013-05-31T07:40:23Z"),
"myState" : 1,
"members" : [
{
"_id" : 2,
"name" : "localhost:10002",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 2,
"optime" : {
"t" : 1369986021,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T07:40:21Z"),
"lastHeartbeat" : ISODate("2013-05-31T07:40:21Z"),
"lastHeartbeatRecv" : ISODate("2013-05-31T07:40:23Z"),
"pingMs" : 2,
"lastHeartbeatMessage" : "db exception in producer: 10278 dbclient error communicating with server: localhost:10003",
"syncingTo" : "localhost:10003"
},
{
"_id" : 3,
"name" : "localhost:10003",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 4539,
"optime" : {
"t" : 1369986021,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T07:40:21Z"),
"self" : true
}
],
"ok" : 1
}

清空node1，数据文件。

rm -rf node1*
ls -l
drwxrwxr-x 3 conan conan 4096 May 31 14:38 node2/
-rw-rw-r-- 1 conan conan 509277 May 31 15:42 node2.log
drwxrwxr-x 3 conan conan 4096 May 31 14:38 node3/
-rw-rw-r-- 1 conan conan 515918 May 31 15:42 node3.log
drwxrwxr-x 2 conan conan 4096 May 31 15:02 repair/

7. 新增加一个Replica Set节点


mkdir node1
mongod --dbpath /home/conan/dbs/node1 --port 10001 --replSet blort --nojournal --fork --logpath /home/conan/dbs/node1.log
about to fork child process, waiting until server is ready for connections.
forked process: 15145
all output going to: /home/conan/dbs/node1.log
child process started successfully, parent exiting

新增加的node1节点

rs.add("localhost:10001")
blort:PRIMARY> rs.status()
{
"set" : "blort",
"date" : ISODate("2013-05-31T07:48:28Z"),
"myState" : 1,
"members" : [
{
"_id" : 2,
"name" : "localhost:10002",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 487,
"optime" : {
"t" : 1369986467,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T07:47:47Z"),
"lastHeartbeat" : ISODate("2013-05-31T07:48:26Z"),
"lastHeartbeatRecv" : ISODate("2013-05-31T07:48:27Z"),
"pingMs" : 0,
"syncingTo" : "localhost:10003"
},
{
"_id" : 3,
"name" : "localhost:10003",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 5024,
"optime" : {
"t" : 1369986467,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T07:47:47Z"),
"self" : true
},
{
"_id" : 4,
"name" : "localhost:10001",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 41,
"optime" : {
"t" : 1369986467,
"i" : 1
},
"optimeDate" : ISODate("2013-05-31T07:47:47Z"),
"lastHeartbeat" : ISODate("2013-05-31T07:48:27Z"),
"lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
"pingMs" : 0,
"syncingTo" : "localhost:10003"
}
],
"ok" : 1
}

增加的localhost:10001, 为SECONDARY.

实验完成！

Replica Set 做为FailOver的实现，还是很不错的。

 

转载请注明：
http://blog.fens.me/mongodb-replica-set/

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