redis cluster配置集群与使用Jedis的ShardedJedis做Redis集群的区别

在看ShardedJedis源码的时候，发现ShardedJedis并没有使用节点的Ip和port做hash，而是用的instance的顺序或者name，太赞了

private void initialize(List<S> shards) {
nodes = new TreeMap<Long, S>();
for (int i = 0; i != shards.size(); ++i) {
final S shardInfo = shards.get(i);
if (shardInfo.getName() == null)
for (int n = 0; n < 160 * shardInfo.getWeight(); n++) {
nodes.put(this.algo.hash("SHARD-" + i + "-NODE-" + n),
shardInfo);
}
else
for (int n = 0; n < 160 * shardInfo.getWeight(); n++) {
nodes.put(
this.algo.hash(shardInfo.getName() + "*"
+ shardInfo.getWeight() + n), shardInfo);
}
resources.put(shardInfo, shardInfo.createResource());
}
}

配置的时候也非常简单:

<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
 <property name="maxTotal" value="1000"/>
 <property name="maxIdle" value="10"/>
 <property name="minIdle" value="1"/>
 <property name="maxWaitMillis" value="30000"/>
 <property name="testOnBorrow" value="true"/>
 <property name="testOnReturn" value="true"/>
 <property name="testWhileIdle" value="true"/>
 </bean>

 <bean id="shardedJedisPool" class="redis.clients.jedis.ShardedJedisPool" destroy-method="destroy">
 <constructor-arg ref="jedisPoolConfig"/>
 <constructor-arg>
 <list>
 <bean class="redis.clients.jedis.JedisShardInfo">
 <constructor-arg value="127.0.0.1"/>
 <constructor-arg type="int" value="7000"/>
 <constructor-arg value="instance:01"/>
 </bean>
 <bean class="redis.clients.jedis.JedisShardInfo">
 <constructor-arg value="127.0.0.1"/>
 <constructor-arg type="int" value="7001"/>
 <constructor-arg value="instance:02"/>
 </bean>
 <bean class="redis.clients.jedis.JedisShardInfo">
 <constructor-arg value="127.0.0.1"/>
 <constructor-arg type="int" value="7003"/>
 <constructor-arg value="instance:03"/>
 </bean>
 </list>
 </constructor-arg>
 </bean>

一开始你可以设置足够多的instance，数据扩容的时候，只需要将几个instance的数据copy到别的机器上。
然后修改配置文件的ip和端口即可。很方便吧？

另外，Jedis还提供了对jedis sentinel pool的封装，所以发生主从切换的时候，web server都不需要重新配置和deploy。高可用性的极佳体现啊。

@Autowired private JedisSentinelPool pool;

public void mymethod() {
 Jedis jedis = null;
 try {
 jedis = pool.getResource();
 jedis.hset(....
 } catch (JedisException je) {
 throw je;
 } finally {
 if (jedis != null) pool.returnResource(jedis);
 }
 }

spring bean的配置：


<bean id="redisSentinel" class="redis.clients.jedis.JedisSentinelPool">
 <constructor-arg index="0" value="mymaster" />
 <constructor-arg index="1">
 <set>
 <value>hostofsentinel:26379</value>
 </set>
 </constructor-arg>
 <constructor-arg index="2" ref="jedisPoolConfig" />
 </bean>```

##redis cluster 客户端(Jedis)

<span style="color: #333333; font-family: Arial, sans-serif;"><span style="color: #333333; font-family: Arial, sans-serif;"> private static BinaryJedisCluster jc;  
  static {  
       //只给集群里一个实例就可以  
        Set<HostAndPort> jedisClusterNodes = new HashSet<HostAndPort>();  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 6380));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 6381));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 6382));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 6383));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 6384));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 7380));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 7381));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 7382));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 7383));  
        jedisClusterNodes.add(new HostAndPort("10.10.34.14", 7384));  
        jc = new BinaryJedisCluster(jedisClusterNodes);  
    }  
@Test  
    public void testBenchRedisSet() throws Exception {  
        final Stopwatch stopwatch = new Stopwatch();  
        List list = buildBlogVideos();  
        for (int i = 0; i < 1000; i++) {  
            String key = "key:" + i;  
            stopwatch.start();  
            byte[] bytes1 = protostuffSerializer.serialize(list);  
            jc.setex(key, 60 * 60, bytes1);  
            stopwatch.stop();  
        }  
        System.out.println("time=" + stopwatch.toString());  
    }</span></span>