MongoDB主从+php实现
环境
172.16.115.202 primary
172.16.111.171 secondary
172.16.115.157 secondary
一、MongoDB安装
1. yum下载安装mongodb
扩展源http://repo.mongodb.org/yum/redhat/mongodb-org-3.0.repo
mongodb-org-3.0.7-1.el6.x86_64.rpm #元数据包，它可以实现自动安装下面的4个组件包
mongodb-org-mongos-3.0.7-1.el6.x86_64.rpm # mongod守护程序，以及相关的配置和初始化脚本
mongodb-org-server-3.0.7-1.el6.x86_64.rpm # mongos守护程序
mongodb-org-shell-3.0.7-1.el6.x86_64.rpm # ongo shell环境
mongodb-org-tools-3.0.7-1.el6.x86_64.rpm # MongoDB工具
2. 编辑配置文件vim /etc/mongod.conf
1）去掉以下两行以#开头的注释，以防重启报错
fork:true
pidFilePath:/var/mongodb/mongod.pid
2）bind_ip绑定多个IP，用逗号隔开，如监听全部，留空即可
3. 修改配置参数，启动mongd
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo never > /sys/kernel/mm/transparent_hugepage/defrag
编辑vim /etc/security/limits.conf，加入内容：
mongod soft nofile 64000
mongod hard nofile 64000
mongod soft nproc 32000
mongod hard nproc 32000
service mongd start
注：启动过程较慢，这是它在写数据/var/lib/mongo，如果启动不了，mongod -f /etc/mongod.conf方式，可以看到报错
4. 编辑三台机器的MongoDB配置文件vim /etc/mongod.conf，重启
内容：
##1）去掉replication的注释
##2）加入下面参数(注意首行留空2个空格，固定格式)：
## 类似于二进制日志
oplogSizeMB: 20
## 副本集名字
replSetName: huangzhenping
5. 查看日志文件tail /var/log/mongodb/mongod.log
6. 主上配置，搭建副本集
use admin # 主上进入admin库
config={_id:"huangzhenping",members:[{_id:0,host:"172.16.115.202:27017"},{_id:1,host:"172.16.115.157:27017"},{_id:2,host:"172.16.111.171:27017"}]} #配置机器
rs.initiate(config) #刷新
rs.status() #查看状态
如下结果：出现三台机器的信息，主的状态已变为PRIMARY
> rs.initiate(config){ "ok" : 1 }huangzhenping:OTHER> rs.status(){ "set" : "huangzhenping", "date" : ISODate("2017-01-14T20:24:59.490Z"), "myState" : 1, "members" : [ { "_id" : 0, "name" : "172.16.115.202:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 297, "optime" : Timestamp(1484425453, 1), "optimeDate" : ISODate("2017-01-14T20:24:13Z"), "electionTime" : Timestamp(1484425455, 1), "electionDate" : ISODate("2017-01-14T20:24:15Z"), "configVersion" : 1, "self" : true }, { "_id" : 1, "name" : "172.16.115.157:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 45, "optime" : Timestamp(1484425453, 1), "optimeDate" : ISODate("2017-01-14T20:24:13Z"), "lastHeartbeat" : ISODate("2017-01-14T20:24:57.851Z"), "lastHeartbeatRecv" : ISODate("2017-01-14T20:24:58.343Z") , "pingMs" : 0, "configVersion" : 1 }, { "_id" : 2, "name" : "172.16.111.171:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 45, "optime" : Timestamp(1484425453, 1), "optimeDate" : ISODate("2017-01-14T20:24:13Z"), "lastHeartbeat" : ISODate("2017-01-14T20:24:57.863Z"), "lastHeartbeatRecv" : ISODate("2017-01-14T20:24:58.262Z") , "pingMs" : 1, "configVersion" : 1 } ], "ok" : 1}huangzhenping:PRIMARY>注：
1）如执行rs.status()命令，没有发现三台机器，需手动执行添加
rs.add("172.16.115.157")
rs.add("172.16.111.171")
2）如从机的状态为"stateStr":"STARTUP"，则需执行：
var config={_id:"huangzhenping",members:[{_id:0,host:"172.16.115.202:27017"},{_id:1,host:"172.16.115.157:27017"},{_id:2,host:"172.16.111.171:27017"}]}
rs.initiate(config)
7. 从上登录，状态已变为：SECONDARY
二、MongoDB主从测试
1. mongodb副本集测试
1）主上建库，建集合
use mydb
db.createCollection('testA')
show dbs
show tables
2）从上查看，已成功同步库和集合
rs.slaveOk()
show dbs
2. 副本集更改权重，模拟主宕机
1）主上设置不同的权重，并查看
cfg = rs.conf()
cfg.members[0].priority = 3
cfg.members[1].priority = 2
cfg.members[2].priority = 1
rs.reconfig(cfg)
rs.config()
查看生效的权重：
huangzhenping:PRIMARY> rs.config(){ "_id" : "huangzhenping", "version" : 2, "members" : [ { "_id" : 0, "host" : "172.16.115.202:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 3, "tags" : { }, "slaveDelay" : 0, "votes" : 1 }, { "_id" : 1, "host" : "172.16.115.157:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 2, "tags" : { }, "slaveDelay" : 0, "votes" : 1 }, { "_id" : 2, "host" : "172.16.111.171:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : { }, "slaveDelay" : 0, "votes" : 1 } ], "settings" : { "chainingAllowed" : true, "heartbeatTimeoutSecs" : 10, "getLastErrorModes" : { }, "getLastErrorDefaults" : { "w" : 1, "wtimeout" : 0 } }}2） 主上禁用27017端口，模拟主宕机
iptables -I INPUT -p tcp --dport 27017 -j DROP
原主上：已连接失败
原一台从机：状态已变为PRIMARY
rs.status()查看状态：
huangzhenping:PRIMARY> rs.status(){ "set" : "huangzhenping", "date" : ISODate("2017-01-22T15:48:15.453Z"), "myState" : 1, "members" : [ { "_id" : 0, "name" : "172.16.115.202:27017", "health" : 0, "state" : 8, "stateStr" : "(not reachable/healthy)", "uptime" : 0, "optime" : Timestamp(0, 0), "optimeDate" : ISODate("1970-01-01T00:00:00Z"), "lastHeartbeat" : ISODate("2017-01-22T15:48:14.551Z"), "lastHeartbeatRecv" : ISODate("2017-01-22T15:48:14.632Z"), "pingMs" : 0, "lastHeartbeatMessage" : "Failed attempt to connect to 172.16.115.202:27017; couldn't connect to server 172.16.115.202:27017 (172.16.115.202), connection attempt failed", "configVersion" : -1 }, { "_id" : 1, "name" : "172.16.115.157:27017", "health" : 1, "state" : 1, "stateStr" : "PRIMARY", "uptime" : 16333, "optime" : Timestamp(1484429320, 1), "optimeDate" : ISODate("2017-01-14T21:28:40Z"), "electionTime" : Timestamp(1485100022, 1), "electionDate" : ISODate("2017-01-22T15:47:02Z"), "configVersion" : 2, "self" : true }, { "_id" : 2, "name" : "172.16.111.171:27017", "health" : 1, "state" : 2, "stateStr" : "SECONDARY", "uptime" : 5989, "optime" : Timestamp(1484429320, 1), "optimeDate" : ISODate("2017-01-14T21:28:40Z"), "lastHeartbeat" : ISODate("2017-01-22T15:48:14.751Z"), "lastHeartbeatRecv" : ISODate("2017-01-22T15:48:14.749Z"), "pingMs" : 0, "lastHeartbeatMessage" : "could not find member to sync from", "configVersion" : 2 } ], "ok" : 1}3）新主上，创建一个库和集合
use mydb2
db.createCollection('testB')
4）恢复旧主，则自动切换为MASTER状态，并同步自己离线时新主上创建的库
iptables -D INPUT -p tcp --dport 27017 -j DROP
三、MongoDB结合php
1. 下载安装mongo扩展模块
wget https://github.com/mongodb/mongo-php-driver-legacy/archive/master.zip
unzip mongo-php-driver-legacy-master.zip
cd mongo-php-driver-legacy-master
/usr/bin/phpize
./configure --with-php-config=/usr/bin/php-config
make;make install
2. 编辑php配置文件vim /etc/php.ini，加载扩展模块
3. 编辑测试文件 vim /usr/local/apache2/htdocs/1.php
内容：
mydb;echo "Database mydb selected";?>
4. 测试 curl localhost/1.php
