mongodb replica set 配置高性能多服务器详解

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

[root@localhost ~]# mkdir /var/lib/{mongodb_2,mongodb_3} 

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

[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

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

mongod -f /etc/mongodb.conf 
mongod -f /etc/mongodb_2.conf 
mongod -f /etc/mongodb_3.conf 

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

> 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}]} 

2,初始化replica set

> rs.initiate(config); 
{ 
 "info" : "Config now saved locally. Should come online in about a minute.", 
 "ok" : 1 
} 

3,查看replica set各节点状态

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 
} 

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

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" } 

 
2,从服务器测试

[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 

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

[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 

1.2,在主库执行命令

repmore:PRIMARY> show dbs; 
Tue Dec 17 04:48:02.392 DBClientCursor::init call() failed 

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。


数据运维技术 » mongodb replica set 配置高性能多服务器详解