redis基础到集群实战笔记
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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"
