文档章节

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

y
 yiqifendou
发布于 2016/10/08 11:43
字数 1780
阅读 114
收藏 1

jedis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
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

@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");
    }
}

本文转载自:http://www.open-open.com/lib/view/open1410485827242.html

共有 人打赏支持
y
粉丝 5
博文 53
码字总数 9177
作品 0
南京
私信 提问

暂无文章

新手也能看懂,消息队列其实很简单

该文已加入开源项目:JavaGuide(一份涵盖大部分Java程序员所需要掌握的核心知识的文档类项目,Star 数接近 16k)。地址:https://github.com/Snailclimb/JavaGuide. 本文内容思维导图: 消息...

阿里云官方博客
39分钟前
5
0
如何在Chrome浏览器中启动deviceready事件(尝试调试phonegap项目)?

我正在开发PhoneGap应用程序,我希望能够在Chrome中调试它,而不是在电话上调试。但是,我在onGetReady()函数中初始化我的代码,该函数在PhoneGap触发“deviceready”事件时触发。由于Chr...

kisshua
今天
9
0
nginx中部署vue打包后的静态文件

如何在nginx中部署静态资源就不描述了, 请看我的这篇博客 将vue脚手架项目打包后的静态文件放到nginx上, 发现有个问题, 即url上有#, 怎么去掉这个#呢. 1 项目中router的mode 路由的mode要为h...

克虏伯
今天
13
0
JS容易理解错误的地方

在这端代码执行的末尾,你会不会hi变量回事函数中的hi了?你会不会认为这不是按引用传递了? 对值传递和引用传递产生质疑了? 1 var hi = {};2 function sayHello(hi) { ...

器石_
今天
10
0
Java开发学习--MongoDB

之前只学过sql,第一次使用非关系型数据库。以前对于关系型数据库与非关系型数据库的概念很模糊,通过这次的学习对这两者有了一个清晰的概念。 主键 在MongoDB中,主键名叫"_id",如果在生成...

微笑向暖wx
今天
10
0

没有更多内容

加载失败,请刷新页面

加载更多

返回顶部
顶部