redis之初探

FragranceM

    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;
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)));
//}
//
}
}