mongodb 副本集
系统：centos6.5
IP：10.19.21.244 主节点
10.19.21.245 备节点
10.19.21.248 仲裁点
不只是主节点、副本节点、仲裁节点，还有Secondary-Only、Hidden、Delayed、Non-Voting。
Secondary-Only:不能成为primary节点，只能作为secondary副本节点，防止一些性能不高的节点成为主节点。
Hidden:这类节点是不能够被客户端制定IP引用，也不能被设置为主节点，但是可以投票，一般用于备份数据。
Delayed：可以指定一个时间延迟从primary节点同步数据。主要用于备份数据，如果实时同步，误删除数据马上同步到从节点，恢复又恢复不了。
Non-Voting：没有选举权的secondary节点，纯粹的备份数据节点。
三台主机安装mongodb
下载mongodb wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-2.6.9.tgz 解压到目录 tar xf mongodb-linux-x86_64-2.6.9.tgz -C /usr/local/src 更改名 mv mongodb-linux-x86_64-2.6.9 /usr/local/mongodb cd /usr/local/mongodb/ 创建数据目录和日志目录 mkdir -p data log 创建用户 useradd mongodb -s /sbin/nologin 更改目录属主属组 chown mongod:mongodb /usr/local/mongodb -R 更改环境变量 vim ~/.bash_profile PATH=$PATH:/usr/local/mongodb/bin source ~/.bash_profile
配置文件 vim /etc/mongodb.conf port = 27017 fork = true logpath = /usr/local/mongodb/log/mongodb.log dbpath =/usr/local/mongodb/data/ journal = true #以目录的形式存数据，如果已经存在，修改此配置会导致原始数据消失（注释次参数会回来），除非迁移现有数据文件到directoryperdb所产生的数据目录中。 directoryperdb=true #日志增加形式写入 logappend=true #配置副本集，指定副本名称作为参数，所有主机都必须有相同名称作为同一个副本集 replSet=testrs #使用预分配方式来保证写入性能的稳定，预分配在后台进行，并且每个预分配的文件都用0进行填充。这会让MongoDB始终保持额外的空间和空余的数据文件，从而避免了数据增长过快而带来的分配磁盘空间引起的阻塞。设置noprealloc= true来禁用预分配的数据文件，会缩短启动时间，但在正常操作过程中，可能会导致性能显著下降。 noprealloc=true
启动服务 mongod -f /etc/mongodb.conf
首先连接主节点
mongo
> use admin
> conf = {_id:"testrs",members:[{_id:0,host:"10.19.21.244:27017",priority:2},{_id:1,host:"10.19.21.245:27017",priority:1},{_id:2,host:"10.19.21.248:27017",arbiterOnly:true}]};
{
"_id" : "testrs",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "10.19.21.244:27017",
"priority" : 2
},
{
"_id" : 1,
"host" : "10.19.21.245:27017"
},
{
"_id" : 2,
"host" : "10.19.21.248:27017",
"arbiterOnly" : true
}
]
}
注意最初的_id的值就是我们配置文件中设定的replSet的值，arbiterOnly是大写的O，配置完成后进行初始化：
> rs.initiate(conf)
{
"info" : "Config now saved locally. Should come online in about a minute.",
"ok" : 1
}
此步骤必须备节点和仲裁节点的mongo启动，不然无法执行此步骤。
> rs.status()
{
"set" : "testrs",
"date" : ISODate("2015-05-07T11:55:17Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "10.19.21.244:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 5737,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"electionTime" : Timestamp(1430993992, 1),
"electionDate" : ISODate("2015-05-07T10:19:52Z"),
"self" : true
},
{
"_id" : 1,
"name" : "10.19.21.245:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 3077,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"lastHeartbeat" : ISODate("2015-05-07T11:55:17Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T11:55:17Z"),
"pingMs" : 0,
"syncingTo" : "10.19.21.244:27017"
},
{
"_id" : 2,
"name" : "10.19.21.248:27017",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 5735,
"lastHeartbeat" : ISODate("2015-05-07T11:55:17Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T11:55:17Z"),
"pingMs" : 0
}
],
"ok" : 1
}
> use test
插入数据
> db.testdb.insert({"tset1":"i'm master"})
然后到备份节点查看数据是否有
mongo 10.19.21.245
testrs:SECONDARY> use test
switched to db test
testrs:SECONDARY> show tables;
2015-05-07T19:57:29.670+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
需要进行配置
testrs:SECONDARY> db.setSlaveOk()
testrs:SECONDARY> show tables;
system.indexes
testdb
testrs:SECONDARY> db.testdb.find()
{ "_id" : ObjectId("554a4ee4eb804a0f1b6ec347"), "test1" : "i'm master" }
停止主节点，查看整个集群状态
testrs:PRIMARY> rs.status()
{
"set" : "testrs",
"date" : ISODate("2015-05-07T11:59:42Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "10.19.21.244:27017",
"health" : 0,
"state" : 8,
"stateStr" : "(not reachable/healthy)",
"uptime" : 0,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"lastHeartbeat" : ISODate("2015-05-07T11:59:40Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T11:59:32Z"),
"pingMs" : 0
},
{
"_id" : 1,
"name" : "10.19.21.245:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 3342,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"electionTime" : Timestamp(1430999976, 1),
"electionDate" : ISODate("2015-05-07T11:59:36Z"),
"self" : true
},
{
"_id" : 2,
"name" : "10.19.21.248:27017",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 3340,
"lastHeartbeat" : ISODate("2015-05-07T11:59:42Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T11:59:41Z"),
"pingMs" : 0
}
],
"ok" : 1
}
主节点已切换过来，此时备节点已经变成了主节点。再插入一条数据
testrs:PRIMARY> db.testdb.insert({"test2":"i'm new master"})
testrs:PRIMARY> db.testdb.find();
{ "_id" : ObjectId("554a4ee4eb804a0f1b6ec347"), "test1" : "i'm master" }
{ "_id" : ObjectId("554a505d494f70c600422b41"), "test2" : "i'm new master" }
重启原来的主节点查看状态
testrs:SECONDARY> rs.status()
{
"set" : "testrs",
"date" : ISODate("2015-05-07T14:00:33Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "10.19.21.244:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 15,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"electionTime" : Timestamp(1431007222, 1),
"electionDate" : ISODate("2015-05-07T14:00:22Z"),
"self" : true
},
{
"_id" : 1,
"name" : "10.19.21.245:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 13,
"optime" : Timestamp(1430995665, 1),
"optimeDate" : ISODate("2015-05-07T10:47:45Z"),
"lastHeartbeat" : ISODate("2015-05-07T14:00:32Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T14:00:33Z"),
"pingMs" : 0,
"lastHeartbeatMessage" : "syncing to: 10.19.21.244:27017",
"syncingTo" : "10.19.21.244:27017"
},
{
"_id" : 2,
"name" : "10.19.21.248:27017",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 13,
"lastHeartbeat" : ISODate("2015-05-07T14:00:32Z"),
"lastHeartbeatRecv" : ISODate("2015-05-07T14:00:33Z"),
"pingMs" : 0
}
],
"ok" : 1
}
查看数据是否同步过来
testrs:PRIMARY> use test
switched to db test
testrs:PRIMARY> db.testdb.find()
{ "_id" : ObjectId("554a4ee4eb804a0f1b6ec347"), "test1" : "i'm master" }
{ "_id" : ObjectId("554a505d494f70c600422b41"), "test2" : "i'm new master" }
向集群中增加节点
cfg = rs.conf()
cfg.members[3] = {_id:3,host:"10.19.21.246:27017",priority:0.5}
rs.reconfig(cfg)
如果备份节点无法读取数据，需要设置db.setSlaveOK()。如果备份节点可读但不可写，修改优先级
cfg = rs.conf()
cfg.members[0].priority = 0.5
cfg.members[1].priority = 2
cfg.members[2].priority = 2
rs.reconfig(cfg)
需要 reconfig后配置才能生效。
php与mongodb连接
<?php
$options = array(
'replicaSet' => 'testrs',
'readPreference' => 'secondaryPreferred',
);
$m = new MongoClient("mongodb://10.19.21.244:27017,10.19.21.245:27017/", $options);
foreach ( $m->getConnections() as $c )
{
echo $c['hash'], ":\n",
" - {$c['connection']['connection_type_desc']}, ",
"{$c['connection']['ping_ms']} ms\n";
}
?>
primary:默认参数，只从主节点上进行读取操作；
primaryPreferred:大部分从主节点上读取数据,只有主节点不可用时从secondary节点读取数据。
secondary:只从secondary节点上进行读取操作，存在的问题是secondary节点的数据会比primary节点数据“旧”。
secondaryPreferred:优先从secondary节点进行读取操作，secondary节点不可用时从主节点读取数据；
nearest:不管是主节点、secondary节点，从网络延迟最低的节点上读取数据。