redis之初探

 

    之前nosql群里的哥们对redis讨论的挺热闹，今天我也着手试了吧，主要测试2个方面（只是简单测试了下，主要针对jedis java客户端，jedis已实现了consistent hash算法）

 

1：在多节点下，数据的分布均匀情况如何
2：在多节点下，删除可增加节点后，对原有数据的映射关系，及命中情况如何

 

本机上启动3个节点（6379、6380、6381）

第一：测试数据分布测试情况：

3个节点下，插入10000条数据情况，数据分布还是挺理想的

 

节点	数据量	分布率
6379 node	3365	33.65%
6380 node	3243	32.43%
6381 node	3392	33.92%

 

 

第二：测试增删节点后，对原有数据的影响

 

 

a:首先本机的3个节点（6379、6380、6381），插入10条数据（数据少，分布的还是不均匀的），数据的分布情况为：

 

key:0 put in :127.0.0.1:6380
key:1 put in :127.0.0.1:6380
key:2 put in :127.0.0.1:6381
key:3 put in :127.0.0.1:6381
key:4 put in :127.0.0.1:6380
key:5 put in :127.0.0.1:6381
key:6 put in :127.0.0.1:6379
key:7 put in :127.0.0.1:6380
key:8 put in :127.0.0.1:6381
key:9 put in :127.0.0.1:6379

 

 

b:再把6381节点服务停掉，代码里面不修改节点配置，发现该正确hit的key还是能正确hit到自己的节点（此时后台会抛连接redis异常）

 

key:0 from :127.0.0.1:6380->0
key:1 from :127.0.0.1:6380->1
key:2 from :127.0.0.1:6381->null
key:3 from :127.0.0.1:6381->null
key:4 from :127.0.0.1:6380->4
key:5 from :127.0.0.1:6381->null
key:6 from :127.0.0.1:6379->6
key:7 from :127.0.0.1:6380->7
key:8 from :127.0.0.1:6381->null
key:9 from :127.0.0.1:6379->9

 

 

c:再启动6381这个节点服务，代码里面的配置remove掉6381，然后重新get所有的key，可以看到该正确hit的key也还是能正确hit到自己的节点

 

 

key:0 from :127.0.0.1:6380->0
key:1 from :127.0.0.1:6380->1
key:2 from :127.0.0.1:6380->null
key:3 from :127.0.0.1:6380->null
key:4 from :127.0.0.1:6380->4
key:5 from :127.0.0.1:6380->null
key:6 from :127.0.0.1:6379->6
key:7 from :127.0.0.1:6380->7
key:8 from :127.0.0.1:6380->null
key:9 from :127.0.0.1:6379->9

 

 

 

其实以上测试已经说明了，jedis客服端在移除或者添加一个cache节点时，不影响原有数据的映射关系，这也是一致性hash算法的原理。就这么测这么点，自己玩玩而已，至于性能如何，官方说的挺不错的，大家可以自己去看看...整一个新的分布式缓存我觉得这些必要的测试还是需要的，下面把测试代码发出来，写的很简单，就2个类：

 

 

import java.util.ArrayList;
import java.util.List;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.ShardedJedis;
import redis.clients.jedis.ShardedJedisPool;
import redis.clients.util.Hashing;
import redis.clients.util.Sharded;

/**
 * 
 * @Title: RedisResourcePool.java 
 * @Copyright: Copyright (c) 2005
 * @Description: <br> <br>
 * @Company: hd
 * @Created on May 4, 2012 3:05:44 PM
 * @author <a href="mailTo:tangzhibin@*.com">tangzhibin</a>
 */
public class RedisResourcePool {
	
	/**ShardedJedisPool底层实现了commons.pool中的GenericObjectPool对象池,it's thread-safety*/
	private ShardedJedisPool shareRedisPool;
	
	void initRedisPool(){
		JedisPoolConfig configs=new JedisPoolConfig();
		/**对象池中最大活动的对象个数*/
		configs.setMaxActive(200);
		/**对象的最大空闲时间*/
		configs.setMaxIdle(60*1000);
		/**客户端获取对象时，如果池中没有空闲的对象(已达MaxActive)，则会等待MaxWait时间，在此时间内，如果还没有空闲的对象返回，则抛出异常*/
		configs.setMaxWait(5*1000);
		
		/**设置host port等配置*/
		String []hostPorts={"127.0.0.1:6379","127.0.0.1:6380","127.0.0.1:6381"};
		//String []hostPorts={"127.0.0.1:6379","127.0.0.1:6380"};
		List<JedisShardInfo> jdsInfoList =new ArrayList<JedisShardInfo>(hostPorts.length);
		for(int i=0;i<hostPorts.length;i++){
			String hostPort=hostPorts[i];
			String[] host_port=hostPort.split(":");
			String host=host_port[0];
			/**注意port一定要转为int类型(不能为String),否则JedisShardInfod初始化时， 会将该String作为节点name名称,而把默认的6379作为端口号*/
			int port=Integer.parseInt(host_port[1]);
			JedisShardInfo jedisShardInfo=new JedisShardInfo(host,port);
			jdsInfoList.add(jedisShardInfo);
		}
		/**初始化redis池*/
		this.shareRedisPool = new ShardedJedisPool(configs, jdsInfoList,
				Hashing.MURMUR_HASH, Sharded.DEFAULT_KEY_TAG_PATTERN);
	}
	
	private RedisResourcePool(){
		initRedisPool();
	}
	
    static class RedisResourcePoolIniter{
		
		private static final RedisResourcePool redisResourcePool=new RedisResourcePool();
		
		private static RedisResourcePool getRedisResourcePool(){
			return redisResourcePool;
		}
	}
	
	public ShardedJedis getRedisCacheResource(){
		return shareRedisPool.getResource();
	}
	
	public void restoreRedisCacheResource(ShardedJedis resource){
		if(shareRedisPool!=null && resource!=null){
			shareRedisPool.returnResource(resource);
		}
	}
	
	public static RedisResourcePool getRedisResourcePool(){
		return RedisResourcePoolIniter.getRedisResourcePool();
	}
}

 

 

测试的main函数在此类中

import redis.clients.jedis.Client;
import redis.clients.jedis.ShardedJedis;
/**
 * 
 * @Title: RedisManager.java 
 * @Copyright: Copyright (c) 2005
 * @Description: <br> <br>
 * @Company: hd
 * @Created on May 4, 2012 3:05:44 PM
 * @author <a href="mailTo:tangzhibin">tangzhibin</a>
 */
public class RedisManager {
	
	private RedisResourcePool redisResourcePool=RedisResourcePool.getRedisResourcePool();

	private RedisManager(){}
	
	private static class RedisManagerIniter{
		
		private static final RedisManager redisManager=new RedisManager();
		
		private static RedisManager getRedisManager(){
			return redisManager;
		}
	}
	
	public static RedisManager getRedisManager(){
		return RedisManagerIniter.getRedisManager();
	}
	

	public String set(String key,String value){
		ShardedJedis resource=null;
		try{
			resource=redisResourcePool.getRedisCacheResource();
			Client cli=resource.getShard(key).getClient();
			return resource.set(key, value);
		}finally{
			redisResourcePool.restoreRedisCacheResource(resource);
		}
	}
	
	public Object get(String key){
		ShardedJedis resource=null;
		try{
			resource=redisResourcePool.getRedisCacheResource();
			Client cli=resource.getShard(key).getClient();
			System.out.println("key:"+key+" from :"+cli.getHost()+":"+cli.getPort());
			return resource.get(key);
		}catch(Exception ex){
			ex.printStackTrace();
			return null;
		}finally{
			redisResourcePool.restoreRedisCacheResource(resource);
		}
	}
	
   

	public static void main(String[] args){
		
		RedisManager rm=RedisManager.getRedisManager();
		//set
		for(int i=0;i<10000;i++){
			rm.set(String.valueOf(i),String.valueOf(i));
		}
		
//		//get
//		for(int i=0;i<10;i++){
//			System.out.println(rm.get(String.valueOf(i)));
//		}
//		
		
	}
}