【转载】Redis的Java客户端Jedis的八种调用方式(事务、管道、分布式…)介绍

转载地址：http://blog.csdn.net/truong/article/details/46711045

关键字：Redis的Java客户端Jedis的八种调用方式(事务、管道、分布式…)介绍 
Tags: redis, jedis, 事务, 管道, 分布式, 连接池

redis是一个著名的key-value存储系统，而作为其官方推荐的java版客户端jedis也非常强大和稳定，支持事务、管道及有jedis自身实现的分布式。

在这里对jedis关于事务、管道和分布式的调用方式做一个简单的介绍和对比： 
一、普通同步方式

最简单和基础的调用方式，

@Test 
public void test1Normal() { 
    Jedis jedis = new Jedis("localhost"); 
    long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        String result = jedis.set("n" + i, "n" + i); 
    } 
    long end = System.currentTimeMillis(); 
    System.out.println("Simple SET: " + ((end - start)/1000.0) + " seconds"); 
    jedis.disconnect(); 
}

很简单吧，每次set之后都可以返回结果，标记是否成功。 
二、事务方式(Transactions)

redis的事务很简单，他主要目的是保障，一个client发起的事务中的命令可以连续的执行，而中间不会插入其他client的命令。

看下面例子：

@Test 
public void test2Trans() { 
    Jedis jedis = new Jedis("localhost"); 
    long start = System.currentTimeMillis(); 
    Transaction tx = jedis.multi(); 
    for (int i = 0; i < 100000; i++) { 
        tx.set("t" + i, "t" + i); 
    } 
    List<Object> results = tx.exec(); 
    long end = System.currentTimeMillis(); 
    System.out.println("Transaction SET: " + ((end - start)/1000.0) + " seconds"); 
    jedis.disconnect(); 
}

我们调用jedis.watch(…)方法来监控key，如果调用后key值发生变化，则整个事务会执行失败。另外，事务中某个操作失败，并不会回滚其他操作。这一点需要注意。还有，我们可以使用discard()方法来取消事务。 
三、管道(Pipelining)

有时，我们需要采用异步方式，一次发送多个指令，不同步等待其返回结果。这样可以取得非常好的执行效率。这就是管道，调用方法如下：

@Test 
public void test3Pipelined() { 
    Jedis jedis = new Jedis("localhost"); 
    Pipeline pipeline = jedis.pipelined(); 
    long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        pipeline.set("p" + i, "p" + i); 
    } 
    List<Object> results = pipeline.syncAndReturnAll(); 
    long end = System.currentTimeMillis(); 
    System.out.println("Pipelined SET: " + ((end - start)/1000.0) + " seconds"); 
    jedis.disconnect(); 
}

四、管道中调用事务

就Jedis提供的方法而言，是可以做到在管道中使用事务，其代码如下：

@Test 
public void test4combPipelineTrans() { 
    jedis = new Jedis("localhost"); 
    long start = System.currentTimeMillis(); 
    Pipeline pipeline = jedis.pipelined(); 
    pipeline.multi(); 
    for (int i = 0; i < 100000; i++) { 
        pipeline.set("" + i, "" + i); 
    } 
    pipeline.exec(); 
    List<Object> results = pipeline.syncAndReturnAll(); 
    long end = System.currentTimeMillis(); 
    System.out.println("Pipelined transaction: " + ((end - start)/1000.0) + " seconds"); 
    jedis.disconnect(); 
}

但是经测试（见本文后续部分），发现其效率和单独使用事务差不多，甚至还略微差点。 
五、分布式直连同步调用

@Test 
public void test5shardNormal() { 
    List<JedisShardInfo> shards = Arrays.asList( 
            new JedisShardInfo("localhost",6379), 
            new JedisShardInfo("localhost",6380));

ShardedJedis sharding = new ShardedJedis(shards);

long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        String result = sharding.set("sn" + i, "n" + i); 
    } 
    long end = System.currentTimeMillis(); 
    System.out.println("Simple@Sharing SET: " + ((end - start)/1000.0) + " seconds");

sharding.disconnect(); 
}

这个是分布式直接连接，并且是同步调用，每步执行都返回执行结果。类似地，还有异步管道调用。 
六、分布式直连异步调用

@Test 
public void test6shardpipelined() { 
    List<JedisShardInfo> shards = Arrays.asList( 
            new JedisShardInfo("localhost",6379), 
            new JedisShardInfo("localhost",6380));

ShardedJedis sharding = new ShardedJedis(shards);

ShardedJedisPipeline pipeline = sharding.pipelined(); 
    long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        pipeline.set("sp" + i, "p" + i); 
    } 
    List<Object> results = pipeline.syncAndReturnAll(); 
    long end = System.currentTimeMillis(); 
    System.out.println("Pipelined@Sharing SET: " + ((end - start)/1000.0) + " seconds");

sharding.disconnect(); 
}

七、分布式连接池同步调用 （适用于2.2及以下版本）

如果，你的分布式调用代码是运行在线程中，那么上面两个直连调用方式就不合适了，因为直连方式是非线程安全的，这个时候，你就必须选择连接池调用。

@Test 
public void test7shardSimplePool() { 
    List<JedisShardInfo> shards = Arrays.asList( 
            new JedisShardInfo("localhost",6379), 
            new JedisShardInfo("localhost",6380));

ShardedJedisPool pool = new ShardedJedisPool(new JedisPoolConfig(), shards);

ShardedJedis one = pool.getResource();

long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        String result = one.set("spn" + i, "n" + i); 
    } 
    long end = System.currentTimeMillis(); 
    pool.returnResource(one); 
    System.out.println("Simple@Pool SET: " + ((end - start)/1000.0) + " seconds");

pool.destroy(); 
}

上面是同步方式，当然还有异步方式。 
八、分布式连接池异步调用 （适用于2.2及以下版本）

@Test 
public void test8shardPipelinedPool() { 
    List<JedisShardInfo> shards = Arrays.asList( 
            new JedisShardInfo("localhost",6379), 
            new JedisShardInfo("localhost",6380));

ShardedJedisPool pool = new ShardedJedisPool(new JedisPoolConfig(), shards);

ShardedJedis one = pool.getResource();

ShardedJedisPipeline pipeline = one.pipelined();

long start = System.currentTimeMillis(); 
    for (int i = 0; i < 100000; i++) { 
        pipeline.set("sppn" + i, "n" + i); 
    } 
    List<Object> results = pipeline.syncAndReturnAll(); 
    long end = System.currentTimeMillis(); 
    pool.returnResource(one); 
    System.out.println("Pipelined@Pool SET: " + ((end - start)/1000.0) + " seconds"); 
    pool.destroy(); 
}

九、需要注意的地方

事务和管道都是异步模式。在事务和管道中不能同步查询结果。比如下面两个调用，都是不允许的：

Transaction tx = jedis.multi(); 
     for (int i = 0; i < 100000; i++) { 
         tx.set("t" + i, "t" + i); 
     } 
     System.out.println(tx.get("t1000").get());  //不允许

List<Object> results = tx.exec();

… 
     …

Pipeline pipeline = jedis.pipelined(); 
     long start = System.currentTimeMillis(); 
     for (int i = 0; i < 100000; i++) { 
         pipeline.set("p" + i, "p" + i); 
     } 
     System.out.println(pipeline.get("p1000").get()); //不允许

List<Object> results = pipeline.syncAndReturnAll();

事务和管道都是异步的，个人感觉，在管道中再进行事务调用，没有必要，不如直接进行事务模式。

分布式中，连接池的性能比直连的性能略好(见后续测试部分)。

分布式调用中不支持事务。

因为事务是在服务器端实现，而在分布式中，每批次的调用对象都可能访问不同的机器，所以，没法进行事务。

十、测试

运行上面的代码，进行测试，其结果如下：

Simple SET: 5.227 seconds

Transaction SET: 0.5 seconds 
Pipelined SET: 0.353 seconds 
Pipelined transaction: 0.509 seconds

Simple@Sharing SET: 5.289 seconds 
Pipelined@Sharing SET: 0.348 seconds

Simple@Pool SET: 5.039 seconds 
Pipelined@Pool SET: 0.401 seconds

另外，经测试分布式中用到的机器越多，调用会越慢。上面是2片，下面是5片：

Simple@Sharing SET: 5.494 seconds 
Pipelined@Sharing SET: 0.51 seconds 
Simple@Pool SET: 5.223 seconds 
Pipelined@Pool SET: 0.518 seconds

下面是10片：

Simple@Sharing SET: 5.9 seconds 
Pipelined@Sharing SET: 0.794 seconds 
Simple@Pool SET: 5.624 seconds 
Pipelined@Pool SET: 0.762 seconds

下面是100片：

Simple@Sharing SET: 14.055 seconds 
Pipelined@Sharing SET: 8.185 seconds 
Simple@Pool SET: 13.29 seconds 
Pipelined@Pool SET: 7.767 seconds

分布式中，连接池方式调用不但线程安全外，根据上面的测试数据，也可以看出连接池比直连的效率更好。 
十一、完整的测试代码

package com.example.nosqlclient;

import java.util.Arrays; 
import java.util.List;

import org.junit.AfterClass; 
import org.junit.BeforeClass; 
import org.junit.Test;

import redis.clients.jedis.Jedis; 
import redis.clients.jedis.JedisPoolConfig; 
import redis.clients.jedis.JedisShardInfo; 
import redis.clients.jedis.Pipeline; 
import redis.clients.jedis.ShardedJedis; 
import redis.clients.jedis.ShardedJedisPipeline; 
import redis.clients.jedis.ShardedJedisPool; 
import redis.clients.jedis.Transaction;

import org.junit.FixMethodOrder; 
import org.junit.runners.MethodSorters;

@FixMethodOrder(MethodSorters.NAME_ASCENDING) 
public class TestJedis {

private static Jedis jedis; 
    private static ShardedJedis sharding; 
    private static ShardedJedisPool pool;

@BeforeClass 
    public static void setUpBeforeClass() throws Exception { 
        List<JedisShardInfo> shards = Arrays.asList( 
                new JedisShardInfo("localhost",6379), 
                new JedisShardInfo("localhost",6379)); //使用相同的ip:port,仅作测试

jedis = new Jedis("localhost"); 
        sharding = new ShardedJedis(shards);

pool = new ShardedJedisPool(new JedisPoolConfig(), shards); 
    }

@AfterClass 
    public static void tearDownAfterClass() throws Exception { 
        jedis.disconnect(); 
        sharding.disconnect(); 
        pool.destroy(); 
    }

@Test 
    public void test1Normal() { 
        long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            String result = jedis.set("n" + i, "n" + i); 
        } 
        long end = System.currentTimeMillis(); 
        System.out.println("Simple SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test2Trans() { 
        long start = System.currentTimeMillis(); 
        Transaction tx = jedis.multi(); 
        for (int i = 0; i < 100000; i++) { 
            tx.set("t" + i, "t" + i); 
        } 
        //System.out.println(tx.get("t1000").get());

List<Object> results = tx.exec(); 
        long end = System.currentTimeMillis(); 
        System.out.println("Transaction SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test3Pipelined() { 
        Pipeline pipeline = jedis.pipelined(); 
        long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            pipeline.set("p" + i, "p" + i); 
        } 
        //System.out.println(pipeline.get("p1000").get()); 
        List<Object> results = pipeline.syncAndReturnAll(); 
        long end = System.currentTimeMillis(); 
        System.out.println("Pipelined SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test4combPipelineTrans() { 
        long start = System.currentTimeMillis(); 
        Pipeline pipeline = jedis.pipelined(); 
        pipeline.multi(); 
        for (int i = 0; i < 100000; i++) { 
            pipeline.set("" + i, "" + i); 
        } 
        pipeline.exec(); 
        List<Object> results = pipeline.syncAndReturnAll(); 
        long end = System.currentTimeMillis(); 
        System.out.println("Pipelined transaction: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test5shardNormal() { 
        long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            String result = sharding.set("sn" + i, "n" + i); 
        } 
        long end = System.currentTimeMillis(); 
        System.out.println("Simple@Sharing SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test6shardpipelined() { 
        ShardedJedisPipeline pipeline = sharding.pipelined(); 
        long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            pipeline.set("sp" + i, "p" + i); 
        } 
        List<Object> results = pipeline.syncAndReturnAll(); 
        long end = System.currentTimeMillis(); 
        System.out.println("Pipelined@Sharing SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test7shardSimplePool() { 
        ShardedJedis one = pool.getResource();

long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            String result = one.set("spn" + i, "n" + i); 
        } 
        long end = System.currentTimeMillis(); 
        pool.returnResource(one); 
        System.out.println("Simple@Pool SET: " + ((end - start)/1000.0) + " seconds"); 
    }

@Test 
    public void test8shardPipelinedPool() { 
        ShardedJedis one = pool.getResource();

ShardedJedisPipeline pipeline = one.pipelined();

long start = System.currentTimeMillis(); 
        for (int i = 0; i < 100000; i++) { 
            pipeline.set("sppn" + i, "n" + i); 
        } 
        List<Object> results = pipeline.syncAndReturnAll(); 
        long end = System.currentTimeMillis(); 
        pool.returnResource(one); 
        System.out.println("Pipelined@Pool SET: " + ((end - start)/1000.0) + " seconds"); 
    } 
}