redis缓存的使用总结

本人使用了redis3.0版本。3.0版本主要增加了redis集群功能。

安装的前提条件：安装gcc：yum install gcc-c++

1、下载redis的源码包。

2、把源码包上传到linux服务器

3、解压源码包 tar -zxvf redis-3.0.0.tar.gz

4、Make

5、Make install

[root@shuang redis-3.0.0]# make install PREFIX=/usr/local/redis

1.1 启动redis

1、前端启动模式

/usr/local/redis/bin/redis-server

默认是前端启动模式，端口是6379

2、后端启动

1）从redis的源码目录中复制redis.conf到redis的安装目录。

2）修改配置文件redis.conf

3）[root@shuang bin]# ./redis-server redis.conf

1.2 redis的常用命令

127.0.0.1:6379> set a 10

OK

127.0.0.1:6379> get a

"10"

等等

1.3 redis常用数据类型

String

Hash

List

Set

SortedSet

1. 4Redis集群的搭建

redis-cluster把所有的物理节点映射到[0-16383]slot上,cluster负责维护node<->slot<->value

Redis 集群中内置了 16384 个哈希槽，当需要在Redis 集群中放置一个key-value 时，redis先对 key使用 crc16算法算出一个结果，然后把结果对 16384求余数，这样每个 key都会对应一个编号在 0-16383之间的哈希槽，redis会根据节点数量大致均等的将哈希槽映射到不同的节点

例如：

Key:a

计算a的hash值，例如值为100，100这个槽在server1上，所以a应该放到server1.

 

Key:hello

Hash值：10032，此槽在server2上。Hell可以应该存在server2.

1.5 redis-cluster投票:容错

(1)领着投票过程是集群中所有master参与,如果半数以上master节点与master节点通信超过(cluster-node-timeout),认为当前master节点挂掉.

(2):什么时候整个集群不可用(cluster_state:fail)? 

a:如果集群任意master挂掉,且当前master没有slave.集群进入fail状态,也可以理解成集群的slot映射[0-16383]不完成时进入fail状态.

 ps : redis-3.0.0.rc1加入cluster-require-full-coverage参数,默认关闭,打开集群兼容部分失败.

    b:如果集群超过半数以上master挂掉，无论是否有slave集群进入fail状态.

  ps:当集群不可用时,所有对集群的操作做都不可用，收到((error) CLUSTERDOWN The cluster is down)错误

二 redis集群

1.1 我的集群结构

集群中有三个节点的集群，每个节点有一主一备。需要6台虚拟机。

搭建一个伪分布式的集群，使用6个redis实例来模拟。

 

1.2 搭建集群需要的环境

搭建集群需要使用到官方提供的ruby脚本。

需要安装ruby的环境。

 

安装ruby

yum install ruby

yum install rubygems

 

redis集群管理工具redis-trib.rb

[root@shuang ~]# cd redis-3.0.0

[root@shuang redis-3.0.0]# cd src

[root@shuang src]# ll *.rb

-rwxrwxr-x. 1 root root 48141 Apr  1 07:01 redis-trib.rb

[root@shuang src]#

 

脚本需要的ruby包：

需要上传到linux服务。

安装ruby的包：

gem install redis-3.0.0.gem

[root@bogon ~]# gem install redis-3.0.0.gem

Successfully installed redis-3.0.0

1 gem installed

Installing ri documentation for redis-3.0.0...

Installing RDoc documentation for redis-3.0.0...

1.3 集群的搭建

第一步：创建6个redis实例，端口号从7001~7006

第二步：修改redis的配置文件

1、修改端口号

2、打开cluster-enable前面的注释。

第三步：把创建集群的ruby脚本复制到redis-cluster目录下。

第四步：启动6个redis实例

第五步：创建集群。

./redis-trib.rb create --replicas 1 192.168.25.153:7001 192.168.25.153:7002 192.168.25.153:7003 192.168.25.153:7004 192.168.25.153:7005  192.168.25.153:7006

[root@shuang redis-cluster]# ./redis-trib.rb create --replicas 1 192.168.25.153:7001 192.168.25.153:7002 192.168.25.153:7003 192.168.25.153:7004 192.168.25.153:7005  192.168.25.153:7006

>>> Creating cluster

Connecting to node 192.168.25.153:7001: OK

Connecting to node 192.168.25.153:7002: OK

Connecting to node 192.168.25.153:7003: OK

Connecting to node 192.168.25.153:7004: OK

Connecting to node 192.168.25.153:7005: OK

Connecting to node 192.168.25.153:7006: OK

>>> Performing hash slots allocation on 6 nodes...

Using 3 masters:

192.168.25.153:7001

192.168.25.153:7002

192.168.25.153:7003

Adding replica 192.168.25.153:7004 to 192.168.25.153:7001

Adding replica 192.168.25.153:7005 to 192.168.25.153:7002

Adding replica 192.168.25.153:7006 to 192.168.25.153:7003

M: 5a8523db7e12ca600dc82901ced06741b3010076 192.168.25.153:7001

   slots:0-5460 (5461 slots) master

M: bf6f0929044db485dea9b565bb51e0c917d20a53 192.168.25.153:7002

   slots:5461-10922 (5462 slots) master

M: c5e334dc4a53f655cb98fa3c3bdef8a808a693ca 192.168.25.153:7003

   slots:10923-16383 (5461 slots) master

S: 2a61b87b49e5b1c84092918fa2467dd70fec115f 192.168.25.153:7004

   replicates 5a8523db7e12ca600dc82901ced06741b3010076

S: 14848b8c813766387cfd77229bd2d1ffd6ac8d65 192.168.25.153:7005

   replicates bf6f0929044db485dea9b565bb51e0c917d20a53

S: 3192cbe437fe67bbde9062f59d5a77dabcd0d632 192.168.25.153:7006

   replicates c5e334dc4a53f655cb98fa3c3bdef8a808a693ca

Can I set the above configuration? (type 'yes' to accept): yes

>>> Nodes configuration updated

>>> Assign a different config epoch to each node

>>> Sending CLUSTER MEET messages to join the cluster

Waiting for the cluster to join.....

>>> Performing Cluster Check (using node 192.168.25.153:7001)

M: 5a8523db7e12ca600dc82901ced06741b3010076 192.168.25.153:7001

   slots:0-5460 (5461 slots) master

M: bf6f0929044db485dea9b565bb51e0c917d20a53 192.168.25.153:7002

   slots:5461-10922 (5462 slots) master

M: c5e334dc4a53f655cb98fa3c3bdef8a808a693ca 192.168.25.153:7003

   slots:10923-16383 (5461 slots) master

M: 2a61b87b49e5b1c84092918fa2467dd70fec115f 192.168.25.153:7004

   slots: (0 slots) master

   replicates 5a8523db7e12ca600dc82901ced06741b3010076

M: 14848b8c813766387cfd77229bd2d1ffd6ac8d65 192.168.25.153:7005

   slots: (0 slots) master

   replicates bf6f0929044db485dea9b565bb51e0c917d20a53

M: 3192cbe437fe67bbde9062f59d5a77dabcd0d632 192.168.25.153:7006

   slots: (0 slots) master

   replicates c5e334dc4a53f655cb98fa3c3bdef8a808a693ca

[OK] All nodes agree about slots configuration.

>>> Check for open slots...

>>> Check slots coverage...

[OK] All 16384 slots covered.

[root@shuang redis-cluster]# 

1.4 测试集群

[root@shuang redis-cluster]# redis01/redis-cli -h 192.168.25.153 -p 7002-c

[root@shuang redis-cluster]# redis01/redis-cli -h 192.168.25.153 -p 7002

192.168.25.153:7002> set a 100

(error) MOVED 15495 192.168.25.153:7003

192.168.25.153:7002>

[root@shuang redis-cluster]# redis01/redis-cli -h 192.168.25.153 -p 7002 -c

192.168.25.153:7002> set a 100

-> Redirected to slot [15495] located at 192.168.25.153:7003

OK

192.168.25.153:7003> 

1.5 关闭redis

redis01/redis-cli -p 7001 shutdown

三、java使用redis--Jedis客户端

需要把jedis的jar包添加到工程中，如果是maven需要添加jar包的坐标。

单机版测试类

public class JedisTest {@Testpublic void testJedisSingle() {//创建一个jedis的对象。Jedis jedis = new Jedis("192.168.25.153", 6379);//调用jedis对象的方法，方法名称和redis的命令一致。jedis.set("key1", "jedis test");String string = jedis.get("key1");System.out.println(string);//关闭jedis。jedis.close();}/** * 使用连接池 */@Testpublic void testJedisPool() {//创建jedis连接池JedisPool pool = new JedisPool("192.168.25.153", 6379);//从连接池中获得Jedis对象Jedis jedis = pool.getResource();String string = jedis.get("key1");System.out.println(string);//关闭jedis对象jedis.close();pool.close();}

集群版测试类

@Testpublic void testJedisCluster() {HashSet<HostAndPort> nodes = new HashSet<>();nodes.add(new HostAndPort("192.168.25.153", 7001));nodes.add(new HostAndPort("192.168.25.153", 7002));nodes.add(new HostAndPort("192.168.25.153", 7003));nodes.add(new HostAndPort("192.168.25.153", 7004));nodes.add(new HostAndPort("192.168.25.153", 7005));nodes.add(new HostAndPort("192.168.25.153", 7006));JedisCluster cluster = new JedisCluster(nodes);cluster.set("key1", "1000");String string = cluster.get("key1");System.out.println(string);cluster.close();}

1.1 jedis整合spring

单机版配置

<!-- 连接池配置 --><bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig"><!-- 最大连接数 --><property name="maxTotal" value="30" /><!-- 最大空闲连接数 --><property name="maxIdle" value="10" /><!-- 每次释放连接的最大数目 --><property name="numTestsPerEvictionRun" value="1024" /><!-- 释放连接的扫描间隔（毫秒） --><property name="timeBetweenEvictionRunsMillis" value="30000" /><!-- 连接最小空闲时间 --><property name="minEvictableIdleTimeMillis" value="1800000" /><!-- 连接空闲多久后释放, 当空闲时间>该值 且 空闲连接>最大空闲连接数 时直接释放 --><property name="softMinEvictableIdleTimeMillis" value="10000" /><!-- 获取连接时的最大等待毫秒数,小于零:阻塞不确定的时间,默认-1 --><property name="maxWaitMillis" value="1500" /><!-- 在获取连接的时候检查有效性, 默认false --><property name="testOnBorrow" value="true" /><!-- 在空闲时检查有效性, 默认false --><property name="testWhileIdle" value="true" /><!-- 连接耗尽时是否阻塞, false报异常,ture阻塞直到超时, 默认true --><property name="blockWhenExhausted" value="false" /></bean><!-- jedis客户端单机版 --><bean id="redisClient" class="redis.clients.jedis.JedisPool"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="6379"></constructor-arg><constructor-arg name="poolConfig" ref="jedisPoolConfig"></constructor-arg></bean>

/** * 单机版测试 * <p>Title: testSpringJedisSingle</p> * <p>Description: </p> */@Testpublic void testSpringJedisSingle() {ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext-*.xml");JedisPool pool = (JedisPool) applicationContext.getBean("redisClient");Jedis jedis = pool.getResource();String string = jedis.get("key1");System.out.println(string);jedis.close();pool.close();}

集群版配置

<bean id="redisClient" class="redis.clients.jedis.JedisCluster"><constructor-arg name="nodes"><set><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7001"></constructor-arg></bean><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7002"></constructor-arg></bean><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7003"></constructor-arg></bean><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7004"></constructor-arg></bean><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7005"></constructor-arg></bean><bean class="redis.clients.jedis.HostAndPort"><constructor-arg name="host" value="192.168.25.153"></constructor-arg><constructor-arg name="port" value="7006"></constructor-arg></bean></set></constructor-arg><constructor-arg name="poolConfig" ref="jedisPoolConfig"></constructor-arg></bean>

@Testpublic void testSpringJedisCluster() {ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext-*.xml");JedisCluster jedisCluster =  (JedisCluster) applicationContext.getBean("redisClient");String string = jedisCluster.get("key1");System.out.println(string);jedisCluster.close();}

jedis类使用redis的封装（单机版）

public class JedisClientSingle implements JedisClient{@Autowiredprivate JedisPool jedisPool; @Overridepublic String get(String key) {Jedis jedis = jedisPool.getResource();String string = jedis.get(key);jedis.close();return string;}@Overridepublic String set(String key, String value) {Jedis jedis = jedisPool.getResource();String string = jedis.set(key, value);jedis.close();return string;}@Overridepublic String hget(String hkey, String key) {Jedis jedis = jedisPool.getResource();String string = jedis.hget(hkey, key);jedis.close();return string;}@Overridepublic long hset(String hkey, String key, String value) {Jedis jedis = jedisPool.getResource();Long result = jedis.hset(hkey, key, value);jedis.close();return result;}@Overridepublic long incr(String key) {Jedis jedis = jedisPool.getResource();Long result = jedis.incr(key);jedis.close();return result;}@Overridepublic long expire(String key, int second) {Jedis jedis = jedisPool.getResource();Long result = jedis.expire(key, second);jedis.close();return result;}@Overridepublic long ttl(String key) {Jedis jedis = jedisPool.getResource();Long result = jedis.ttl(key);jedis.close();return result;}}

jedis类使用redis的封装（集群版）

public class JedisClientCluster implements JedisClient {@Autowiredprivate JedisCluster jedisCluster;@Overridepublic String get(String key) {return jedisCluster.get(key);}@Overridepublic String set(String key, String value) {return jedisCluster.set(key, value);}@Overridepublic String hget(String hkey, String key) {return jedisCluster.hget(hkey, key);}@Overridepublic long hset(String hkey, String key, String value) {return jedisCluster.hset(hkey, key, value);}@Overridepublic long incr(String key) {return jedisCluster.incr(key);}@Overridepublic long expire(String key, int second) {return jedisCluster.expire(key, second);}@Overridepublic long ttl(String key) {return jedisCluster.ttl(key);}}

把缓存添加到业务逻辑示例，这里可以用到切面的思想更加简单

@Overridepublic List<TbContent> getContentList(long contentCid) {//从缓存中取内容try {String result = jedisClient.hget(INDEX_CONTENT_REDIS_KEY, contentCid + "");if (!StringUtils.isBlank(result)) {//把字符串转换成listList<TbContent> resultList = JsonUtils.jsonToList(result, TbContent.class);return resultList;}} catch (Exception e) {e.printStackTrace();}//根据内容分类id查询内容列表TbContentExample example = new TbContentExample();Criteria criteria = example.createCriteria();criteria.andCategoryIdEqualTo(contentCid);//执行查询List<TbContent> list = contentMapper.selectByExample(example);//向缓存中添加内容try {//把list转换成字符串String cacheString = JsonUtils.objectToJson(list);jedisClient.hset(INDEX_CONTENT_REDIS_KEY, contentCid + "", cacheString);} catch (Exception e) {e.printStackTrace();}return list;}