redis cluster jedis client 示例

redis cluster 基本的redis操作示例:

JedisCluster jc = null;
    @Before
    public void before(){
        Set<HostAndPort> jedisClusterNodes = new HashSet<HostAndPort>();
        //Jedis Cluster will attempt to discover cluster nodes automatically
        jedisClusterNodes.add(new HostAndPort("127.0.0.1", 7000));
        jc = new JedisCluster(jedisClusterNodes);
    }
    @Test
    public void test_incr(){
         
        String key = "page_view";
        jc.del(key);
        jc.incr(key);
        String result = jc.get(key);
        System.out.println(result);
        Assertions.assertThat(result).isEqualTo(1+"");
    }
    @Test
    public void test_setAndGetStringVal(){
        String key = "foo";
        String value = "bar";
        jc.set(key, value);
        String result = jc.get(key);
        System.out.println(result);
        Assertions.assertThat(result).isEqualTo(value);
    }
    @Test
    public void test_setAndGetStringVal_and_set_expire() throws InterruptedException{
        String key = "hello";
        String value = "world";
        int seconds = 3;
        jc.setex(key, seconds , value);
        String result = jc.get(key);
        System.out.println(result);
        Assertions.assertThat(result).isEqualTo(value);
        Thread.sleep(seconds*1000);
        result = jc.get(key);
        System.out.println(result);
        Assertions.assertThat(result).isNull();
         
    }
    @Test
    public void test_setAndGetHashVal(){
         
        String key = "website";
        String field= "google";
        String value = "google.com";
        jc.del(key);
        jc.hset(key, field, value);
        String result = jc.hget(key, field);
        System.out.println(result);
        Assertions.assertThat(result).isEqualTo(value);
    }
    @Test
    public void test_setAndGetListVal(){
         
        String key = "mylist";
        jc.del(key);
        String[] vals = {"a","b","c"};
        jc.rpush(key, vals);
        List<String> result = jc.lrange(key, 0, -1);
        System.out.println(result);
        Assertions.assertThat(result).containsExactly(vals);
    }
    @Test
    public void test_setAndGetSetVal(){
         
        String key = "language";
        jc.del(key);
        String[] members = {"java", "ruby", "python"};
        jc.sadd(key, members);
        Set<String> result = jc.smembers(key);
        System.out.println(result);
        Assertions.assertThat(result).containsOnly(members);
    }

演示主从切换时的jedis操作情景:

JedisCluster jc = null;
    @Before
    public void before(){
        Set<HostAndPort> jedisClusterNodes = new HashSet<HostAndPort>();
        //Jedis Cluster will attempt to discover cluster nodes automatically
        jedisClusterNodes.add(new HostAndPort("127.0.0.1", 7000));
        jc = new JedisCluster(jedisClusterNodes);
    }
    /**
     * 在一个无限循环中不停的读写
     * @throws InterruptedException
     */
    @Test
    public void setAndWriteStringValueRepeatedly() throws InterruptedException{
        String key = "test_oper_during_failover";
        jc.del(key);
        long failureTime = 0;
        long recoveryTime = 0;
        while(true){
            try {
                String result = jc.get(key);
                if(failureTime != 0 && recoveryTime==0){
                    recoveryTime =  System.currentTimeMillis();
                    System.out.println("Cluster is recovered! Downtime lasted "+(recoveryTime-failureTime)+" ms");
                }
                     
                System.out.println(result);
                jc.set(key, System.currentTimeMillis()+"");
                 
            } catch (Exception e) {
                if(failureTime==0)
                    failureTime=System.currentTimeMillis();
                e.printStackTrace();
            }
            Thread.sleep(1000);
        }
         
    }

输出：

null
1430663109857
1430663110860
......
redis.clients.jedis.exceptions.JedisClusterMaxRedirectionsException: Too many Cluster redirections?
    at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:37)
    at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:70)
    ...
...
redis.clients.jedis.exceptions.JedisClusterException: CLUSTERDOWN The cluster is down
    at redis.clients.jedis.Protocol.processError(Protocol.java:111)
    at redis.clients.jedis.Protocol.process(Protocol.java:138)
    ...
Cluster is recovered! Downtime lasted 7089 ms
1430663137897
1430663146602
...

pom.xml:

<properties>
        <junit.version>4.11</junit.version>
        <assertj.version>1.7.0</assertj.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.6.2</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <!-- assertj -->
        <dependency>
            <groupId>org.assertj</groupId>
            <artifactId>assertj-core</artifactId>
            <version>${assertj.version}</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

参考:

https://github.com/xetorthio/jedis

问题：

1.  hostandport 只需要指定一个 host ip和端口？其他的都直接由rediscluster去获取是吧？

   摘自http://redis.io/topics/cluster-tutorial

   此段话是针对ruby client的， 但是我想应该也适用于jedis。

 3  startup_nodes = [
     4      {:host => "127.0.0.1", :port => 7000},
     5      {:host => "127.0.0.1", :port => 7001}
     6  ]
 
The startup nodes don't need to be all the nodes of the cluster. The important thing is that at least one node is reachable. Also note that redis-rb-cluster updates this list of startup nodes as soon as it is able to connect with the first node. You should expect such a behavior with any other serious client.

来源：oschina

链接：https://my.oschina.net/u/1175066/blog/411077