spring-data-redis读写分离

谁践踏了优雅 2022-03-30 14:47 219阅读 0赞

在对Redis进行性能优化时，一直想对Redis进行读写分离。但由于项目底层采用spring-data-redis对redis进行操作，参考spring官网却发现spring-data-redis目前(1.7.0.RELEASE)及以前的版本并不支持读写分离。

**一、源码分析**

spring-data-redis中关于JedisConnectionFactory的配置如下：

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<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:p="http://www.springframework.org/schema/p"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd">
            
        <bean id="redisSentinelConfiguration" class="org.springframework.data.redis.connection.RedisSentinelConfiguration">
            <property name="master">
                <bean class="org.springframework.data.redis.connection.RedisNode">
                    <property name="name" value="mymaster"/>
                    <constructor-arg name="host" value="${redis.master.host}"></constructor-arg>
                    <constructor-arg name="port" value="${redis.master.port}"></constructor-arg>
                </bean>
            </property>
            <property name="sentinels">
                <set>
                    <bean class="org.springframework.data.redis.connection.RedisNode">
                        <constructor-arg name="host" value="${redis.sentinel1.host}"></constructor-arg>
                        <constructor-arg name="port" value="${redis.sentinel1.port}"></constructor-arg>
                    </bean>
                    <bean class="org.springframework.data.redis.connection.RedisNode">
                        <constructor-arg name="host" value="${redis.sentinel2.host}"></constructor-arg>
                        <constructor-arg name="port" value="${redis.sentinel2.port}"></constructor-arg>
                    </bean>
                    <bean class="org.springframework.data.redis.connection.RedisNode">
                        <constructor-arg name="host" value="${redis.sentinel3.host}"></constructor-arg>
                        <constructor-arg name="port" value="${redis.sentinel3.port}"></constructor-arg>
                    </bean>
                </set>
            </property>
        </bean>
        
        
        <bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
            <property name="maxTotal" value="${redis.pool.maxActive}" />
            <property name="maxIdle" value="${redis.pool.maxIdle}" />
            
            <property name="testOnBorrow" value="${redis.pool.testOnBorrow}" />
            <property name="testOnReturn" value="${redis.pool.testOnReturn}" />
        </bean>
        
        <bean id="jedisConnectionFactory"
              class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
            <property name="poolConfig" ref="jedisPoolConfig"></property>  
            <constructor-arg ref="redisSentinelConfiguration"/>
        </bean>
    
        <bean id="stringRedisTemplate" 
              class="org.springframework.data.redis.core.StringRedisTemplate" 
              p:connection-factory-ref="jedisConnectionFactory"/>
    </beans>

查看JedisConnectionFactory源码发现pool是Pool<Jedis>，而不是Pool<ShardedJedis>。因此我猜目前spring data redis是做不了读写分离的，stringRedisTemplate读写操作都是在master上。

**二、读写分离改造**

参考sentinel的主备选举机制对spring-data-redis的相关配置进行如下改造：

读写分离原理如下所示：

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(1)Spring配置

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<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:p="http://www.springframework.org/schema/p"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd">
            
           <context:property-placeholder  location="classpath:redis/redis.properties" ignore-unresolvable="true" />
           
           <bean id="poolConfig" class="redis.client.jedis.JedisPoolConfig">
                <property name="maxIdle" value="${redis.maxIdle}" />
                <property name="maxTotal" value="${redis.maxTotal}" />
                <property name="maxWaitMillis" value="${redis.maxWait}" />
                <property name="testOnBuorrow" value="${redis.testOnBorrow}" />
            </bean>
    
        <bean id="redisSentinelConfiguration" class="org.springframework.data.redis.connection.RedisSentinelConfiguration">
         <constructor-arg index="0">
              <bean class="org.springframework.core.env.MapPropertySource">
                <constructor-arg index="0" value="RedisSentinelConffiguration" />
                <constructor-arg index="1">
                   <map>
                    <entry key="spring.redis.sentinel.master" value="${redis.sentinel.master}"></entry>
                    <entry key="spring.redis.sentinel.nodes" value="${redis.sentinel.nodes"}> </entry>
                    </map>
                 </constructor-arg>
                 </bean>
                </constructor-arg>
        </bean>
        
        <bean id="connectionFactory" class="com.test.data.redis.connection.TWJedisConnectionFactory">
           <constructor-arg index="0" ref="redisSentinelConfiguration" />
           <constructor-arg index="1" ref="poolConfig" />
           <property name="password" value="${redis.pass}" />
           <property name="databse" value="7" />
        </bean>
         
        <bean id="readOnlyConnectionFactory" class="com.test.data.redis.connection.TWReadOnlyJedisConnectionFactory">
           <constructor-arg index="0" ref="redisSentinelConfiguration" />
           <constructor-arg index="1" ref="poolConfig" />
           <property name="password" value="${redis.pass}" />
           <property name="databse" value="7" />
        </bean>
        
    
        <bean id="redisTemplate" class="com.test.data.redis.core.TWRedisTemplate" 
           <property name="connectionFactory" ref="connectionFactory"/>
           <property name="readOnlyConnectionFactory" ref="readOnlyConnectionFactory" />
         </bean>
    </beans>

(2)TWJedisConnectionFactory

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public class TWJedisConnectionFactory extends JedisConnectionFactory {
     
      public TWJedisConnectionFactory() {
         super();
      }
      
      public TWJedisConnectionFactory(JedisShardInfo shardInfo) {
         super(shardInfo);
      }
    
      public TWJedisConnectionFactory(JedisPoolConfig poolConfig){
         this((RedisSentinelConfiguration)null,poolConfig);
      }
      
      public TWJedisConnectionFactory(RedisSentinelConfiguration sentinelConfig){
         this(sentinelConfig,null);
      }
     
      public TWJedisConnectionFactory(RedisSentinelConfiguration sentinelConfig,JedisPoolConfig poolConfig){
         super(sentinelConfig,poolConfig);
      }
    
      public TWJedisConnectionFactory(RedisClusterConfiguration clusterConfig){
         super(clusterConfig);
      }
      
      public TWJedisConnectionFactory(RedisClusterConfiguration clusterConfig,JedisPoolConfig poolConfig){
         super(clusterConfig,poolConfig);
      }
    
      @Override
      public void afterPropertiesSet() {
       try {
        super.afterPropertiesSet();
       }catch(Exception e) {
       }
      }
    }

(3)TWReadOnlyJedisConnectionFactory

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public class TWReadOnlyJedisConnectionFactory extends JedisConnectionFactory {
    
      private static final Method GET_TIMEOUT_METHOD;
    
      static {
         Method getTimeoutMethodCandidate = ReflectionUtils.findMethod(JedisShardInfo.class,"getTimeout");
         if(null == getTimeoutMethodCandidate) {
           getTimeoutMethodCandidate = ReflectionUtils.findMethod(JedisShardInfo.class,"getTimeout");
         }
         GET_TIMEOUT_METHOD=getTimeoutMethodCandidate;
      }
     
      public TWReadOnlyJedisConnectionFactory() {
         super();
      }
      
      public TWReadOnlyJedisConnectionFactory(JedisShardInfo shardInfo) {
         super(shardInfo);
      }
    
      public TWReadOnlyJedisConnectionFactory(JedisPoolConfig poolConfig){
         this((RedisSentinelConfiguration)null,poolConfig);
      }
      
      public TWReadOnlyJedisConnectionFactory(RedisSentinelConfiguration sentinelConfig){
         this(sentinelConfig,null);
      }
     
      public TWReadOnlyJedisConnectionFactory(RedisSentinelConfiguration sentinelConfig,JedisPoolConfig poolConfig){
         super(sentinelConfig,poolConfig);
      }
    
      public TWReadOnlyJedisConnectionFactory(RedisClusterConfiguration clusterConfig){
         super(clusterConfig);
      }
      
      public TWJedisConnectionFactory(RedisClusterConfiguration clusterConfig,JedisPoolConfig poolConfig){
         super(clusterConfig,poolConfig);
      }
    
      @Override
      public void afterPropertiesSet() {
       try {
        super.afterPropertiesSet();
       }catch(Exception e) {
       }  
      }
    
      protected Pool<Jedis> createRedisSentinelPool(RedisSentinelConfiguration config){
        return new JedisSentinelSlavePool(config.getMaster().getName(),
               convertToJedisSentinelSet(config.getSentinels()),
               getPoolConfig()!=null?getPoolConfig():new JedisPoolConfig(),
               getTimeOutFrom(getShardInfo()),
               getShardInfo().getPassword());
      }
    
     private Set<String> convertToJedisSentinelSet(Collection<RedisNode> nodes) {
      if(CollectionUtils.isEmpty(nodes)) {
        return Collections.emptySet();
      }
      Set<String> convertedNodes = new LinkedHashSet<String>(nodes.size());
      for(RedisNode node : nodes)
       {
         convertedNodes.add(node.asString());
       }
      return convertedNodes;
     }
     
     private int getTimeOutFrom(JedisShardInfo shardInfo){
      return (Integer) ReflectionUtils.invokeMethod(GET_TIMEOUT_METHOD,shardInfo);
     }
    
    }

(4)TWRedisTemplate

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public class TWRedisTemplate extends RedisTemplate {
      public static enum Operation {read,write};
      
      private static ThreadLocal<Operation> threadLocal = new ThreadLocal<TWRedisTemplate.Operation>();
      
      private RedisConnectionFactory readOnlyConnectionFactory;  
      
      public void setReadOnlyConnectionFactory(RedisConnectionFactory readOnlyConnectionFactory) {
        this.readOnlyConnectionFactory = readOnlyConnectionFactory;
      }
    
      public TWRedisTemplate() {
      }
    
      @Override
      public void afterPropertiesSet() {
       try {
        super.afterPropertiesSet();
       }catch(Exception e) {
       }  
      }
    
      public RedisConnectionFactory getConnectionFactory() {
        Operation operation = threadLocal.get();
        if(operation!=null && operation==Operation.read && readOnlyConnectionFactory!=null) {
          return readOnlyConnectionFactory;
        }
        return super.getConnectionFactory();
      }
    
     public void setOperation(Operation operation) {
       threadLocal.set(operation);
     }
    }

(5)JedisReadOnlyPool

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public class JedisReadOnlyPool extends Pool<Jedis> {
      protected GenericObjectPoolConfig poolConfig;
      protected int connectionTimeout = Protocol.DEFAULT_TIMEOUT;
      protected int soTimeout = Protocol.DEFAULT_TIMEOUT;
      protected String password;
      protected int database = Protocol.DEFAULT_TIMEOUT;
      private volatile JedisFactory factory;
      private volatile HostAndPort currentHostMaster;
      
      public JedisReadOnlyPool(final HostAndPort master, final GenericObjectPoolConfig poolConfig,
                               final int connectionTimeOut, final int soTimeout, final String password, final int databse,
                               final String clientName) {
             this.poolConfig = poolConfig;
             this.connectionTimeout = connectionTimeout;
             this.soTimeout = soTimeout;
             this.password = password;
             this.database = database;
             initPool(master);
      }
      public void destory() {
       super.destroy();
      }
      
      public void initPool(HostAndPort master) {
        if(!master.equals(currentHostMaster) {
           currentHostMaster = master;
           if(factory == null) {
             factory = new JedisFactory(currentHostMaster.getHost(),
                                        currentHostMaster.getPort(),
                                        connectionTimeout,
                                        soTimeout,
                                        password,
                                        database,
                                        null);
            initPool(poolConfig,factory);
        } else {
            factory.setHostAndPort(currentHostMaster);
            internalPool.clear();
        }
        log.info("Created JedisPool to master at" + master);
       }
      }
    
     private HostAndPort toHostAndPort(List<String> getMasterAddByNameResult) {
       String host = getMasterAddrByNameResult.get(0);
       int port = Integer.parseInt(getMasterAddrByNameResult.get(1));
       return new HostAndPort(host,port);
     }
    
     @Override
     public Jedis getResource() {
       while(true) {
          Jedis jedis = super.getResource();
          jedis.setDataSource(this);
          final HostAndPort connection = new HostAndPort(jedis.getClient().getHost(),jedis.getClient().getPort());
          if(currentHostMaster.equals(connection)) {
            return jedis;
          } else {
            returnBrokenResource(jedis);
          }
       }
     }
     
     @Override
     @Deprecated
     public void returnBrokenResource(final Jedis resource) {
       if(resource!=null) {
         returnBrokenResourceObject(resource);
       }
     }
    
     @Override
     @Deprecated
     public void returnResource(final Jedis resource) {
      if(resource !=null ){
       resource.resetState();
       returnResourceObject(resource);
      }
     }
     
    }

(6)JedisSentinelSlavesPool

(7)RedisCacheService

在具体使用缓存服务时，在读、写缓存时分别加上其类型

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...
    @Autowired
    private TWRedisTemplate twRedisTemplate;
    
    
    public List<String> getCachedByPredis(final String prefix) {
      twRedisTemplate.setOperation(Operation.read);
      ...
      finally {
        destory();
      }
    }
    
    public void hset(xxx) {
      twRedisTemplate.setOperation(Operation.write);
      ...
      finally {
        destory();
      }
      
    }
    
    
    /**释放资源**/
    private void destroy() {
      twRedisTemplate.setOperation(null);
    }

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