mongodb 复制集

mongodb的复制集，大致就是在主从复制的基础上，加入了高可用控制，类似高可用mysql集群

在主节点出现问题后，从节点会重新找出来一个主节点，系统自动完成，mysql如果也这样就完美了，mysql弄这个好复杂

1. 

在linux 下面做3个账号连接，然后依次开启3个mongodb的进程（非守护进行，守护进程只能开启一个）

2.

/usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data1 -logpath=/mongodb/log1/log.log -port=10001  --replSet terry/usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data2 -logpath=/mongodb/log2/log.log -port=10002  --replSet terry/usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data3 -logpath=/mongodb/log3/log.log -port=10003  --replSet terry

查看是否运行成功：

[root@grande ~]# ps -ef | grep mongoroot      2345     1  0 Nov27 ?        01:34:52 /usr/local/mongodb2.6/bin/mongod --dbpath=/usr/local/mongodb2.6/data -logpath=/usr/local/mongodb2.6/log -fork -port=27017root     25111 24779  0 09:13 pts/1    00:00:12 /usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data2 -logpath=/mongodb/log2/log.log -port=10002 --replSet terryroot     25157 24679  0 09:13 pts/0    00:00:12 /usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data1 -logpath=/mongodb/log1/log.log -port=10001 --replSet terryroot     25203 24809  0 09:14 pts/2    00:00:11 /usr/local/mongodb2.6/bin/mongod --dbpath=/mongodb/data3 -logpath=/mongodb/log3/log.log -port=10003 --replSet terryroot     25341 24854  0 09:17 pts/4    00:00:00 mongo 10.10.10.252:10001/adminroot     25895 25288  0 09:38 pts/5    00:00:00 mongo 10.10.10.252:10002root     26089 26069  0 09:44 pts/6    00:00:00 grep mongo

3. 通过上面的运行，我们还需要初始化：

mongo 10.10.10.252:10001/admin  

db.runCommand({"replSetInitiate":{"_id":"terry","members":[{"_id":1,"host":"10.10.10.252:10001"},{"_id":2,"host":"10.10.10.252:10002"}]}})

如果成功： 显示

{"info" : "Config now saved locally.  Should come online in about a minute.","ok" : 1}

显示复制集状态：

rs.status()

> rs.status(){"set" : "terry","date" : ISODate("2015-12-08T01:17:08Z"),"myState" : 1,"members" : [{"_id" : 1,"name" : "10.10.10.252:10001","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 192,"optime" : Timestamp(1449537265, 1),"optimeDate" : ISODate("2015-12-08T01:14:25Z"),"electionTime" : Timestamp(1449537274, 1),"electionDate" : ISODate("2015-12-08T01:14:34Z"),"self" : true},{"_id" : 2,"name" : "10.10.10.252:10002","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 162,"optime" : Timestamp(1449537265, 1),"optimeDate" : ISODate("2015-12-08T01:14:25Z"),"lastHeartbeat" : ISODate("2015-12-08T01:17:06Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T01:17:06Z"),"pingMs" : 0,"syncingTo" : "10.10.10.252:10001"}],"ok" : 1}

把10003添加到副本集： mongo 10.10.10.252:10001/admin  （仲裁服务器）

rs.addArb("10.10.10.252:10003")

terry:PRIMARY> rs.addArb("10.10.10.252:10003"){ "ok" : 1 }terry:PRIMARY> rs.statusfunction () { return db._adminCommand("replSetGetStatus"); }terry:PRIMARY> rs.status(){"set" : "terry","date" : ISODate("2015-12-08T01:18:29Z"),"myState" : 1,"members" : [{"_id" : 1,"name" : "10.10.10.252:10001","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 273,"optime" : Timestamp(1449537501, 1),"optimeDate" : ISODate("2015-12-08T01:18:21Z"),"electionTime" : Timestamp(1449537274, 1),"electionDate" : ISODate("2015-12-08T01:14:34Z"),"self" : true},{"_id" : 2,"name" : "10.10.10.252:10002","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 243,"optime" : Timestamp(1449537501, 1),"optimeDate" : ISODate("2015-12-08T01:18:21Z"),"lastHeartbeat" : ISODate("2015-12-08T01:18:28Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T01:18:28Z"),"pingMs" : 0,"syncingTo" : "10.10.10.252:10001"},{"_id" : 3,"name" : "10.10.10.252:10003","health" : 1,"state" : 7,"stateStr" : "ARBITER","uptime" : 8,"lastHeartbeat" : ISODate("2015-12-08T01:18:27Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T01:18:28Z"),"pingMs" : 0}],"ok" : 1}

查看到3个进程的mongodb的复制集完成，如果添加其他的，还可以陆续添加

4. 执行查询会报错：

但此时在从库中查询报如下错误：

这是正常的现象，对于SECONDARY节点默认是不可读的。因为SECONDARY是不允许读和写的，在写多读少的应用中，使用Replica Sets来实现读写分离。通过在连接时指定或者在主库指定slaveOk，由SECONDARY来分担读的压力，PRIMARY只承担些操作。

解决方法：

第一种：在从节点设置slaveOk（）：

rs.slaveOk();

第二种：在主节点设置：  

db.getMongo().setSlaveOk();

这样就可以查询了。

5. 增加新节点：

rs.add("10.10.10.252:10004");

6.删除新增节点：

terry:PRIMARY> rs.remove("10.10.10.252:10004");2015-12-08T10:30:15.336+0800 DBClientCursor::init call() failed2015-12-08T10:30:15.339+0800 Error: error doing query: failed at src/mongo/shell/query.js:812015-12-08T10:30:15.341+0800 trying reconnect to 10.10.10.252:10001 (10.10.10.252) failed2015-12-08T10:30:15.341+0800 reconnect 10.10.10.252:10001 (10.10.10.252) ok

terry:PRIMARY> rs.status();{"set" : "terry","date" : ISODate("2015-12-08T02:30:37Z"),"myState" : 1,"members" : [{"_id" : 1,"name" : "10.10.10.252:10001","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 4601,"optime" : Timestamp(1449541815, 1),"optimeDate" : ISODate("2015-12-08T02:30:15Z"),"electionTime" : Timestamp(1449537274, 1),"electionDate" : ISODate("2015-12-08T01:14:34Z"),"self" : true},{"_id" : 2,"name" : "10.10.10.252:10002","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 22,"optime" : Timestamp(1449541815, 1),"optimeDate" : ISODate("2015-12-08T02:30:15Z"),"lastHeartbeat" : ISODate("2015-12-08T02:30:37Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T02:30:36Z"),"pingMs" : 0,"lastHeartbeatMessage" : "syncing to: 10.10.10.252:10001","syncingTo" : "10.10.10.252:10001"},{"_id" : 3,"name" : "10.10.10.252:10003","health" : 1,"state" : 7,"stateStr" : "ARBITER","uptime" : 22,"lastHeartbeat" : ISODate("2015-12-08T02:30:37Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T02:30:36Z"),"pingMs" : 0}],"ok" : 1}

7.测试切换

主节点停掉：

terry:PRIMARY> rs.status();{"set" : "terry","date" : ISODate("2015-12-08T03:03:14Z"),"myState" : 1,"members" : [{"_id" : 1,"name" : "10.10.10.252:10001","health" : 0,"state" : 8,"stateStr" : "(not reachable/healthy)","uptime" : 0,"optime" : Timestamp(1449541815, 1),"optimeDate" : ISODate("2015-12-08T02:30:15Z"),"lastHeartbeat" : ISODate("2015-12-08T03:03:13Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T02:32:45Z"),"pingMs" : 0},{"_id" : 2,"name" : "10.10.10.252:10002","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 6565,"optime" : Timestamp(1449543736, 1),"optimeDate" : ISODate("2015-12-08T03:02:16Z"),"electionTime" : Timestamp(1449541974, 1),"electionDate" : ISODate("2015-12-08T02:32:54Z"),"self" : true},{"_id" : 3,"name" : "10.10.10.252:10003","health" : 1,"state" : 7,"stateStr" : "ARBITER","uptime" : 1979,"lastHeartbeat" : ISODate("2015-12-08T03:03:12Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T03:03:13Z"),"pingMs" : 0},{"_id" : 4,"name" : "10.10.10.252:10004","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 58,"optime" : Timestamp(1449543736, 1),"optimeDate" : ISODate("2015-12-08T03:02:16Z"),"lastHeartbeat" : ISODate("2015-12-08T03:03:12Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T03:03:12Z"),"pingMs" : 0,"lastHeartbeatMessage" : "syncing to: 10.10.10.252:10002","syncingTo" : "10.10.10.252:10002"}],"ok" : 1}

可以看到 id为1的状态为"stateStr" : "(not reachable/healthy)",

id为2的变为PRIMARY

在yii2下链接是没有问题的

关于副本集的yii2的配置参看：

http://blog.csdn.net/terry_water/article/details/50215887

重新启动id为1的mongo：

terry:PRIMARY> rs.status();{"set" : "terry","date" : ISODate("2015-12-08T03:06:09Z"),"myState" : 1,"members" : [{"_id" : 1,"name" : "10.10.10.252:10001","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 4,"optime" : Timestamp(1449541815, 1),"optimeDate" : ISODate("2015-12-08T02:30:15Z"),"lastHeartbeat" : ISODate("2015-12-08T03:06:07Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T03:06:08Z"),"pingMs" : 52},{"_id" : 2,"name" : "10.10.10.252:10002","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 6740,"optime" : Timestamp(1449543736, 1),"optimeDate" : ISODate("2015-12-08T03:02:16Z"),"electionTime" : Timestamp(1449541974, 1),"electionDate" : ISODate("2015-12-08T02:32:54Z"),"self" : true},{"_id" : 3,"name" : "10.10.10.252:10003","health" : 1,"state" : 7,"stateStr" : "ARBITER","uptime" : 2154,"lastHeartbeat" : ISODate("2015-12-08T03:06:08Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T03:06:09Z"),"pingMs" : 0},{"_id" : 4,"name" : "10.10.10.252:10004","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 233,"optime" : Timestamp(1449543736, 1),"optimeDate" : ISODate("2015-12-08T03:02:16Z"),"lastHeartbeat" : ISODate("2015-12-08T03:06:08Z"),"lastHeartbeatRecv" : ISODate("2015-12-08T03:06:08Z"),"pingMs" : 0,"syncingTo" : "10.10.10.252:10002"}],"ok" : 1}

可以看到启动成功了

副本集是强大！！！！配置如此简单。