mongodb的多服务器配置,以前写过一篇文章,是master-slave模式的,请参考:详解mongodb 主从配置。master-slave模式,不能自动实现故障转移和恢复。所以推荐大家使用mongodb的replica set,来实现多服务器的高可用。给我的感觉是replica set好像自带了heartbeat功能,挺强大的。
一,三台服务器,1主,2从
服务器1:127.0.0.1:27017
服务器2:127.0.0.1:27018
服务器3:127.0.0.1:27019
1,创建数据库目录
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[root@localhost ~] # mkdir /var/lib/{mongodb_2,mongodb_3}
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在一台机子上面模拟,三台服务器,所以把DB目录分开了。
2,创建配置文件
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[root@localhost ~]# cat /etc/mongodb.conf |awk '{if($0 !~ /^$/ && $0 !~ /^#/) {print $0}}' //主服务器配置
port = 27017 //监听端口
fork = true //后台运行
pidfilepath = /var/run/mongodb/mongodb.pid //进程PID文件
logpath = /var/log/mongodb/mongodb.log //日志文件
dbpath =/var/lib/mongodb //db存放目录
journal = true //存储模式
nohttpinterface = true //禁用http
directoryperdb=true //一个数据库一个文件夹
logappend=true //追加方式写日志
replSet=repmore //集群名称,自定义
oplogSize=1000 //oplog大小
[root@localhost ~]# cat /etc/mongodb_2.conf |awk '{if($0 !~ /^$/ && $0 !~ /^#/) {print $0}}' //从服务器
port = 27018
fork = true
pidfilepath = /var/run/mongodb/mongodb_2.pid
logpath = /var/log/mongodb/mongodb_2.log
dbpath =/var/lib/mongodb_2
journal = true
nohttpinterface = true
directoryperdb=true
logappend=true
replSet=repmore
oplogSize=1000
[root@localhost ~]# cat /etc/mongodb_3.conf |awk '{if($0 !~ /^$/ && $0 !~ /^#/) {print $0}}' //从服务器
port = 27019
fork = true
pidfilepath = /var/run/mongodb/mongodb_3.pid
logpath = /var/log/mongodb/mongodb_3.log
dbpath =/var/lib/mongodb_3
journal = true
nohttpinterface = true
oplogSize = 1000
directoryperdb=true
logappend=true
replSet=repmore
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在这里要注意一点,不要把认证开起来了,不然查看rs.status();时,主从服务器间,无法连接,"lastHeartbeatMessage" : "initial sync couldn't connect to 127.0.0.1:27017"
3,启动三台服务器
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mongod -f /etc/mongodb .conf
mongod -f /etc/mongodb_2 .conf
mongod -f /etc/mongodb_3 .conf
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注意:初次启动时,主服务器比较快的,从服务器有点慢。
二,配置并初始化replica set
1,配置replica set节点
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> config = {_id: "repmore" ,members:[{_id:0,host: '127.0.0.1:27017' ,priority :2},{_id:1,host: '127.0.0.1:27018' ,priority:1},{_id:2,host: '127.0.0.1:27019' ,priority:1}]}
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2,初始化replica set
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> rs.initiate(config);
{
"info" : "Config now saved locally. Should come online in about a minute." ,
"ok" : 1
}
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3,查看replica set各节点状态
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repmore:PRIMARY> rs.status();
{
"set" : "repmore" ,
"date" : ISODate( "2013-12-16T21:01:51Z" ),
"myState" : 2,
"syncingTo" : "127.0.0.1:27017" ,
"members" : [
{
"_id" : 0,
"name" : "127.0.0.1:27017" ,
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY" ,
"uptime" : 33,
"optime" : Timestamp(1387227638, 1),
"optimeDate" : ISODate( "2013-12-16T21:00:38Z" ),
"lastHeartbeat" : ISODate( "2013-12-16T21:01:50Z" ),
"lastHeartbeatRecv" : ISODate( "2013-12-16T21:01:50Z" ),
"pingMs" : 0,
"syncingTo" : "127.0.0.1:27018"
},
{
"_id" : 1,
"name" : "127.0.0.1:27018" ,
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY" ,
"uptime" : 1808,
"optime" : Timestamp(1387227638, 1),
"optimeDate" : ISODate( "2013-12-16T21:00:38Z" ),
"errmsg" : "syncing to: 127.0.0.1:27017" ,
"self" : true
},
{
"_id" : 2,
"name" : "127.0.0.1:27019" ,
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY" ,
"uptime" : 1806,
"optime" : Timestamp(1387227638, 1),
"optimeDate" : ISODate( "2013-12-16T21:00:38Z" ),
"lastHeartbeat" : ISODate( "2013-12-16T21:01:50Z" ),
"lastHeartbeatRecv" : ISODate( "2013-12-16T21:01:51Z" ),
"pingMs" : 0,
"lastHeartbeatMessage" : "syncing to: 127.0.0.1:27018" ,
"syncingTo" : "127.0.0.1:27018"
}
],
"ok" : 1
}
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在这里要注意,rs.initiate初始化也是要一定时间的,刚执行完rs.initiate,我就查看状态,从服务器的stateStr不是SECONDARY,而是stateStr" : "STARTUP2",等一会就好了。
三,replica set主,从测试
1,主服务器测试
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repmore:PRIMARY> show dbs;
local 1.078125GB
repmore:PRIMARY> use test
switched to db test
repmore:PRIMARY> db. test .insert({ 'name' : 'tank' , 'phone' : '12345678' });
repmore:PRIMARY> db. test . find ();
{ "_id" : ObjectId( "52af64549d2f9e75bc57cda7" ), "name" : "tank" , "phone" : "12345678" }
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2,从服务器测试
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[root@localhost mongodb] # mongo 127.0.0.1:27018 //连接
MongoDB shell version: 2.4.6
connecting to: 127.0.0.1:27018 /test
repmore:SECONDARY> show dbs;
local 1.078125GB
test 0.203125GB
repmore:SECONDARY> db. test . find (); // 无权限查看
error: { "$err" : "not master and slaveOk=false" , "code" : 13435 }
repmore:SECONDARY> rs.slaveOk(); // 从库开启
repmore:SECONDARY> db. test . find (); // 从库可看到主库刚插入的数据
{ "_id" : ObjectId( "52af64549d2f9e75bc57cda7" ), "name" : "tank" , "phone" : "12345678" }
repmore:SECONDARY> db. test .insert({ 'name' : 'zhangying' , 'phone' : '12345678' }); // 从库只读,无插入权限
not master
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到这儿,我们的replica set就配置好了。
四,故障测试
前面我说过,mongodb replica set有故障转移功能,下面就模拟一下,这个过程
1,故障转移
1.1,关闭主服务器
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[root@localhost mongodb] # ps aux |grep mongod //查看所有的mongod
root 16977 0.2 1.1 3153692 44464 ? Sl 04:31 0:02 mongod -f /etc/mongodb .conf
root 17032 0.2 1.1 3128996 43640 ? Sl 04:31 0:02 mongod -f /etc/mongodb_2 .conf
root 17092 0.2 0.9 3127976 38324 ? Sl 04:31 0:02 mongod -f /etc/mongodb_3 .conf
root 20400 0.0 0.0 103248 860 pts /2 S+ 04:47 0:00 grep mongod
[root@localhost mongodb] # kill 16977 //关闭主服务器进程
[root@localhost mongodb] # ps aux |grep mongod
root 17032 0.2 1.1 3133124 43836 ? Sl 04:31 0:02 mongod -f /etc/mongodb_2 .conf
root 17092 0.2 0.9 3127976 38404 ? Sl 04:31 0:02 mongod -f /etc/mongodb_3 .conf
root 20488 0.0 0.0 103248 860 pts /2 S+ 04:47 0:00 grep mongod
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1.2,在主库执行命令
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repmore:PRIMARY> show dbs;
Tue Dec 17 04:48:02.392 DBClientCursor::init call() failed
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1.3,从库查看状态,如下图,
replica set 故障测试
以前的从库变主库了,故障转移成功
2,故障恢复
mongod -f /etc/mongodb.conf
启动刚被关闭的主服务器,然后在登录到主服务器,查看状态rs.status();已恢复到最原始的状态了。