Redis集群实战-创新互联

          Redis基础到集群实战笔记

持久化存储

redis介绍

redis是基于key-value的持久化数据库存储系统，redis和memcached服务很想，但是redis支持的数据存储类型

服务更丰富

memcached支持value

redis支持string（字符）list（链表）  set（集合）  push、pop

redis比memcached服务性能好，但是比相对性的关系数据库（如mysql） 相对差

redis支持各种不同方式的排序，与memcached一样，为了保存效率，数据都是缓存在内存中提供服务，但是redis会定时的将

数据存储在磁盘当中，而且redis支持master-slave（主从）同步，这很类似MYSQL

redis优点

可以持久化存储数据

性能很高：redis支持超过100k+秒的读写频率。

丰富的数据类型：strings lists，hashes，Sets数据类型操作

redis支持主从复制

redis应用场景

传统的MYSQL+MEMCACHED架构遇到的问题

MYSQL数据库是适合进行海量数据存储的，加上通过Memcached热点数据放在内存cache中，随着访问量增长，就会出现

问题。

1需要不断的对MYSQL拆库拆表，Memcached也需要不断地扩充，占据大量的运维时间

2Memcached和MYSQL数据一致性问题

3Memcached数据库命中率低或当机，导致大量的访问直接穿透数据库，导致mysql无法支持访问

4跨级方cache同步一致性问题

redis最佳应用场景

1Redis最佳使用场景全部数据是in-memory（内存）

2Redis更多的场景作为Memcached替代

3当需要除key/value之外的更多数据类型支持的时候，使用Redis更合适

4支持持久化

5需要负载均衡的场景（redis主从同步）

redis部署搭建

MASTER 192.168.2.1

SLAVE  192.168.2.4

MASTER:

[root@localhost ~]# ls

anaconda-ks.cfg  bbs  boke  install.log  install.log.syslog  mysql-5.5.32-linux2.6-x86_64.tar.gz  redis-3.0.2.tar.gz  test.sh  www

[root@localhost ~]# tar zxf redis-3.0.2.tar.gz

[root@localhost ~]# cd redis-3.0.2

[root@localhost redis-3.0.2]# make  MALLOC=jemalloc

[root@localhost redis-3.0.2]# make PREFIX=/application/redis install  指定安装路径

SLAVE

[root@localhost ~]# ls

anaconda-ks.cfg  bbs  boke  install.log  install.log.syslog  mysql-5.5.32-linux2.6-x86_64.tar.gz  redis-3.0.2.tar.gz  test.sh  www

[root@localhost ~]# tar zxf redis-3.0.2.tar.gz

[root@localhost ~]# cd redis-3.0.2

[root@localhost redis-3.0.2]# make  MALLOC=jemalloc

[root@localhost redis-3.0.2]# make PREFIX=/application/redis install  指定安装路径

装完后bin有5个命令

[root@localhost bin]# ls

redis-benchmark  redis-check-aof  redis-check-dump  redis-cli  redis-sentinel  redis-server

redis-benchmark redis性能测试工具

redis-check-aof 更新日志检查

redis-check-dump

redis-cli Redis命令操作工具

redis-sentinel 用于本地数据库检查

redis-server Redis服务的启动程序

要想启动Redis要做环境变量

[root@localhost redis]# export PATH=/application/redis/bin/:$PATH

[root@localhost redis]# which  redis-server

/application/redis/bin/redis-server

永久生效修改文件

[root@localhost redis]# vim /etc/profile

export PATH=/application/redis/bin/:$PATH

[root@localhost redis]# . /etc/profile

redis配置

[root@localhost redis-3.0.2]# mkdir /application/redis/conf

[root@localhost redis-3.0.2]# cp redis.conf  /application/redis/conf/

启动Redis

[root@localhost redis-3.0.2]# redis-server  /application/redis/conf/redis.conf

5522:M 18 Feb 05:02:08.448 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._

           _.-``__ ''-._

      _.-``    `.  `_.  ''-._           Redis 3.0.2 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._

 (    '      ,       .-`  | `,    )     Running in standalone mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379

 |    `-._   `._    /     _.-'    |     PID: 5522

  `-._    `-._  `-./  _.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |           http://redis.io

  `-._    `-._`-.__.-'_.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |

  `-._    `-._`-.__.-'_.-'    _.-'

      `-._    `-.__.-'    _.-'

          `-._        _.-'

              `-.__.-'

5522:M 18 Feb 05:02:08.463 # Server started, Redis version 3.0.2

5522:M 18 Feb 05:02:08.464 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.

5522:M 18 Feb 05:02:08.470 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

5522:M 18 Feb 05:02:08.470 * The server is now ready to accept connections on port 6379

vm.overcommit_memory = 1提示这个错误

解决

[root@localhost redis-3.0.2]# sysctl  vm.overcommit_memory=1

vm.overcommit_memory = 1

[root@localhost redis-3.0.2]# redis-server  /application/redis/conf/redis.conf

5560:M 18 Feb 05:05:23.085 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._

           _.-``__ ''-._

      _.-``    `.  `_.  ''-._           Redis 3.0.2 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._

 (    '      ,       .-`  | `,    )     Running in standalone mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379

 |    `-._   `._    /     _.-'    |     PID: 5560

  `-._    `-._  `-./  _.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |           http://redis.io

  `-._    `-._`-.__.-'_.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |

  `-._    `-._`-.__.-'_.-'    _.-'

      `-._    `-.__.-'    _.-'

          `-._        _.-'

              `-.__.-'

5560:M 18 Feb 05:05:23.087 # Server started, Redis version 3.0.2

5560:M 18 Feb 05:05:23.088 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

5560:M 18 Feb 05:05:23.088 * DB loaded from disk: 0.001 seconds

5560:M 18 Feb 05:05:23.088 * The server is now ready to accept connections on port 6379

成功！

测试redis

[root@localhost ~]# redis-cli

127.0.0.1:6379>

创建库查看库

127.0.0.1:6379> set  no002 xiaohu

OK

127.0.0.1:6379> get no002

"xiaohu"

不在命令行创建库

[root@localhost ~]# redis-cli  -h 192.168.2.1 -p 6379 set no001 qi

OK

[root@localhost ~]# redis-cli  -h 192.168.2.1 -p 6379 get no001

"qi"

删除数据库

[root@localhost ~]# redis-cli   del no001

(integer) 1

[root@localhost ~]# redis-cli   get  no001

(nil)

redis类型

字符串类型

列表类型 列表是数组  对应

[root@localhost ~]# redis-cli  rpush messages "hello"

(integer) 1

[root@localhost ~]# redis-cli  rpush messages "hell"

(integer) 2

显示

[root@localhost ~]# redis-cli  lrange messages 0 2

1) "hello"

2) "hell"

redis集合  这种将3个值集合在一个变量值上  对应标签功能

127.0.0.1:6379> sadd myset a

(integer) 1

127.0.0.1:6379> sadd myset b

(integer) 1

127.0.0.1:6379> sadd myset c

(integer) 1

127.0.0.1:6379> smembers myset

1) "c"

2) "b"

3) "a"

redis 主从同步

MASTER 192.168.2.1

SLAVE  192.168.2.4

编辑slave的redis.conf

vim /application/redis/conf/redis.conf

在slaveof下面添加：

slaveof  192.168.2.1  6379 主库地址和端口号

slave查看

[root@localhost redis-3.0.2]# redis-server  /application/redis/conf/redis.conf

6631:S 24 Mar 06:21:26.599 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._

           _.-``__ ''-._

      _.-``    `.  `_.  ''-._           Redis 3.0.2 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._

 (    '      ,       .-`  | `,    )     Running in standalone mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379

 |    `-._   `._    /     _.-'    |     PID: 6631

  `-._    `-._  `-./  _.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |           http://redis.io

  `-._    `-._`-.__.-'_.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |

  `-._    `-._`-.__.-'_.-'    _.-'

      `-._    `-.__.-'    _.-'

          `-._        _.-'

              `-.__.-'

6631:S 24 Mar 06:21:26.611 # Server started, Redis version 3.0.2

6631:S 24 Mar 06:21:26.613 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

6631:S 24 Mar 06:21:26.613 * DB loaded from disk: 0.000 seconds

6631:S 24 Mar 06:21:26.613 * The server is now ready to accept connections on port 6379

6631:S 24 Mar 06:21:27.602 * Connecting to MASTER 192.168.2.1:6379

6631:S 24 Mar 06:21:27.602 * MASTER <-> SLAVE sync started  已经成功

6631:S 24 Mar 06:21:27.603 * Non blocking connect for SYNC fired the event.

6631:S 24 Mar 06:21:27.604 * Master replied to PING, replication can continue...

6631:S 24 Mar 06:21:27.606 * Partial resynchronization not possible (no cached master)

6631:S 24 Mar 06:21:27.611 * Full resync from master: 7a09e0f69c3888561658ec8a480d250d219c2444:1

6631:S 24 Mar 06:21:27.671 * MASTER <-> SLAVE sync: receiving 83 bytes from master

6631:S 24 Mar 06:21:27.671 * MASTER <-> SLAVE sync: Flushing old data

6631:S 24 Mar 06:21:27.671 * MASTER <-> SLAVE sync: Loading DB in memory

6631:S 24 Mar 06:21:27.672 * MASTER <-> SLAVE sync: Finished with success

MASTER查看

[root@localhost ~]# redis-server  /application/redis/conf/redis.conf

2178:M 19 Feb 03:22:56.204 * Increased maximum number of open files to 10032 (it was originally set to 1024).

                _._

           _.-``__ ''-._

      _.-``    `.  `_.  ''-._           Redis 3.0.2 (00000000/0) 64 bit

  .-`` .-```.  ```\/    _.,_ ''-._

 (    '      ,       .-`  | `,    )     Running in standalone mode

 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379

 |    `-._   `._    /     _.-'    |     PID: 2178

  `-._    `-._  `-./  _.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |           http://redis.io

  `-._    `-._`-.__.-'_.-'    _.-'

 |`-._`-._    `-.__.-'    _.-'_.-'|

 |    `-._`-._        _.-'_.-'    |

  `-._    `-._`-.__.-'_.-'    _.-'

      `-._    `-.__.-'    _.-'

          `-._        _.-'

              `-.__.-'

2178:M 19 Feb 03:22:56.224 # Server started, Redis version 3.0.2

2178:M 19 Feb 03:22:56.224 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.

2178:M 19 Feb 03:22:56.224 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

2178:M 19 Feb 03:22:56.224 * DB loaded from disk: 0.000 seconds

2178:M 19 Feb 03:22:56.224 * The server is now ready to accept connections on port 6379

2178:M 19 Feb 03:37:57.011 * 1 changes in 900 seconds. Saving...

2178:M 19 Feb 03:37:57.014 * Background saving started by pid 2374

2374:C 19 Feb 03:37:57.046 * DB saved on disk

2374:C 19 Feb 03:37:57.046 * RDB: 6 MB of memory used by copy-on-write

2178:M 19 Feb 03:37:57.120 * Background saving terminated with success

2178:M 19 Feb 03:52:58.020 * 1 changes in 900 seconds. Saving...

2178:M 19 Feb 03:52:58.031 * Background saving started by pid 2546

2546:C 19 Feb 03:52:58.049 * DB saved on disk

2546:C 19 Feb 03:52:58.049 * RDB: 6 MB of memory used by copy-on-write

2178:M 19 Feb 03:52:58.138 * Background saving terminated with success

2178:M 19 Feb 04:09:04.556 * Slave 192.168.2.4:6379 asks for synchronization

2178:M 19 Feb 04:09:04.556 * Full resync requested by slave 192.168.2.4:6379

2178:M 19 Feb 04:09:04.556 * Starting BGSAVE for SYNC with target: disk

2178:M 19 Feb 04:09:04.557 * Background saving started by pid 2773

2773:C 19 Feb 04:09:04.580 * DB saved on disk

2773:C 19 Feb 04:09:04.581 * RDB: 6 MB of memory used by copy-on-write 主库也接受到了

2178:M 19 Feb 04:09:04.620 * Background saving terminated with success

2178:M 19 Feb 04:09:04.620 * Synchronization with slave 192.168.2.4:6379 succeeded

在从库做个监控，主库写数据验证

[root@localhost ~]# redis-cli  主库创建数据库

127.0.0.1:6379> set t1 xiaohu01

OK

127.0.0.1:6379> get t1

"xiaohu01"

查看从库同步

[root@localhost ~]# redis-cli  -h 192.168.2.4 get t1

"xiaohu01"

远程连接到从库查看数据同步了

[root@localhost ~]# redis-cli  -h localhost -p 6379 monitor 从库开启监控数据库写入

OK

1458772016.182626 [0 192.168.2.1:6379] "PING"

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