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

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

@Testpublic 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：

@Testpublic 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：

@Testpublic 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：

@Testpublic 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

@Testpublic 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

@Testpublic 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

        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。

@Testpublic 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

@Testpublic 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 secondsTransaction SET: 0.5 secondsPipelined SET: 0.353 secondsPipelined transaction: 0.509 secondsSimple@Sharing SET: 5.289 secondsPipelined@Sharing SET: 0.348 secondsSimple@Pool SET: 5.039 secondsPipelined@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 secondsPipelined@Sharing SET: 0.51 secondsSimple@Pool SET: 5.223 secondsPipelined@Pool SET: 0.518 seconds

        下面是10片：

Simple@Sharing SET: 5.9 secondsPipelined@Sharing SET: 0.794 secondsSimple@Pool SET: 5.624 secondsPipelined@Pool SET: 0.762 seconds

        下面是100片：

Simple@Sharing SET: 14.055 secondsPipelined@Sharing SET: 8.185 secondsSimple@Pool SET: 13.29 secondsPipelined@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.bijian.study;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;@SuppressWarnings("unused")@FixMethodOrder(MethodSorters.NAME_ASCENDING)public class TestJedis {private static Jedis jedis;private static ShardedJedis sharding;private static ShardedJedisPool pool;@BeforeClasspublic static void setUpBeforeClass() throws Exception {List<JedisShardInfo> shards = Arrays.asList(new JedisShardInfo("192.168.128.129", 6379), new JedisShardInfo("192.168.128.129",6379)); // 使用相同的ip:port,仅作测试jedis = new Jedis("192.168.128.129");sharding = new ShardedJedis(shards);pool = new ShardedJedisPool(new JedisPoolConfig(), shards);}@AfterClasspublic static void tearDownAfterClass() throws Exception {jedis.disconnect();sharding.disconnect();pool.destroy();}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}@Testpublic 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");}}

运行结果：

 

Simple SET: 24.316 secondsTransaction SET: 2.641 secondsPipelined SET: 1.016 secondsPipelined transaction: 1.484 secondsSimple@Sharing SET: 29.287 secondsPipelined@Sharing SET: 1.953 secondsSimple@Pool SET: 31.537 secondsPipelined@Pool SET: 1.156 seconds

直接查看redis数据库：

[root@localhost bin]# /usr/local/redis/bin/redis-cli127.0.0.1:6379> dbsize(integer) 800000127.0.0.1:6379> 

 

PS：如上实例是基于jedis-2.1.0.jar、commons-pool-1.6.jar、junit-4.11.jar、hamcrest-core-1.3.jar运行的。

 

文章来源：http://www.blogways.net/blog/2013/06/02/jedis-demo.html

本文附件下载:
• commons-pool-1.6.jar (108.5 KB)
• hamcrest-core-1.3.jar (44 KB)
• jedis-2.1.0.jar (136.2 KB)
• junit-4.11.jar (239.3 KB)