Category Archives: Database

Redis的分片技术一般是通过客户端或代理来实现的

1、用jedis实现分片的时候，服务端不需要做任何配置即可

package com.djhu.redis.test;

import java.util.ArrayList;
import java.util.List;

import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.ShardedJedis;

public class JedisShardTest
{
	public static void main(String[] args)
	{
		List<JedisShardInfo> jedisShardInfoList = new ArrayList<JedisShardInfo>();
		jedisShardInfoList.add(new JedisShardInfo("172.16.172.4", 6379));
		jedisShardInfoList.add(new JedisShardInfo("172.16.172.4", 6380));

		ShardedJedis sharded = new ShardedJedis(jedisShardInfoList);
		sharded.set("key01", "a");
		sharded.set("key02", "b");
		sharded.set("key03", "c");
		sharded.set("key04", "d");
		sharded.set("key05", "e");
		
		System.out.println(sharded.get("key03"));
	}
}

2、用Jedis连接池实现分片

package com.djhu.redis.test;

import java.util.ArrayList;
import java.util.List;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisShardInfo;
import redis.clients.jedis.ShardedJedis;
import redis.clients.jedis.ShardedJedisPool;
import redis.clients.jedis.JedisPoolConfig;
import redis.clients.util.Hashing;
import redis.clients.util.Sharded;

public class JedisSharedFactory
{
	// 最大可用连接数，默认值为8，如果赋值为-1则表示不限制
	private static int MAX_TOTAL = 256;
	// 最大空闲连接数，默认值为8
	private static int MAX_IDLE = 32;
	// 最小空闲连接数
	private static int MIN_IDLE = 4;
	// 最大等待连接毫秒数，默认值为-1表示永不超时
	private static int MAX_WAIT = 3000;
	// 连接redis超时时间
	private static int TIMEOUT = 3000;
	// true表示验证连接
	private static boolean TEST_ON_BORROW = true;

	//连接池
	private static ShardedJedisPool jedisPool = null;
	public static void initJedisPool()
	{
		try
		{
			JedisPoolConfig config = new JedisPoolConfig();
			config.setMaxTotal(MAX_TOTAL);
			config.setMaxIdle(MAX_IDLE);
			config.setMinIdle(MIN_IDLE);
			config.setMaxWaitMillis(MAX_WAIT);
			config.setTestOnBorrow(TEST_ON_BORROW);
			
			List<JedisShardInfo> jedisShardInfoList = new ArrayList<JedisShardInfo>();
			jedisShardInfoList.add(new JedisShardInfo("172.16.172.4", 6379));
			jedisShardInfoList.add(new JedisShardInfo("172.16.172.4", 6380));
			jedisPool = new ShardedJedisPool(config, jedisShardInfoList,Hashing.MURMUR_HASH,Sharded.DEFAULT_KEY_TAG_PATTERN);
		} 
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	public synchronized static ShardedJedis getConnection()
	{
		try
		{
			if (jedisPool != null)
			{
				ShardedJedis resource = jedisPool.getResource();
				return resource;
			} else
			{
				return null;
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
			return null;
		}
	}

	public static void returnResource(final ShardedJedis jedis)
	{
		if (jedis != null)
		{
			jedis.close();
		}
	}
	
	public static void main(String[] args)
	{
		initJedisPool();
		ShardedJedis redis = getConnection();
		redis.set("key10", "j");
		redis.set("key11", "k");
		redis.set("key12", "l");
		redis.set("key13", "m");
		redis.set("key14", "n");
		
		System.out.print(redis.get("key12"));
		
		returnResource(redis);
	}
}

1、源码如下

package com.djhu.redis.test;

import java.util.Set;
import java.util.HashSet;

import redis.clients.jedis.HostAndPort;
import redis.clients.jedis.JedisCluster;

public class JedisClusterTest
{
	public static void main(String[] args)
	{
		Set<HostAndPort> jedisClusterNodes = new HashSet<HostAndPort>();  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 6379));  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 6380));  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 6381));  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 6382));  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 6383));  
        jedisClusterNodes.add(new HostAndPort("172.16.172.4", 7384));  
        
		//JedisCluster cluster = new JedisCluster(jedisClusterNodes,3000,1000);
        JedisCluster cluster = new JedisCluster(jedisClusterNodes);
		cluster.set("key10", "j");
		cluster.set("key11", "k");
		cluster.set("key12", "l");
		cluster.set("key13", "m");
		cluster.set("key14", "n");
		
		System.out.println(cluster.get("key12"));
		
	}
}

2、如果遇到下面错误，主要是因为建立cluster时，ip用了127.0.0.1。用其他ip重建一下cluster，就可以解决了。

Exception in thread "main" redis.clients.jedis.exceptions.JedisClusterMaxRedirectionsException: Too many Cluster redirections?
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:34)
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:68)
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:85)
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:68)
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:85)
	at redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:68)
	at redis.clients.jedis.JedisClusterCommand.run(JedisClusterCommand.java:29)
	at redis.clients.jedis.JedisCluster.set(JedisCluster.java:75)

package com.djhu.redis.test;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class JedisFactory
{
	// 最大可用连接数，默认值为8，如果赋值为-1则表示不限制
	private static int MAX_TOTAL = 256;
	// 最大空闲连接数，默认值为8
	private static int MAX_IDLE = 32;
	// 最小空闲连接数
	private static int MIN_IDLE = 4;
	// 最大等待连接毫秒数，默认值为-1表示永不超时
	private static int MAX_WAIT = 3000;
	// 连接redis超时时间
	private static int TIMEOUT = 3000;
	// true表示验证连接
	private static boolean TEST_ON_BORROW = true;

	//连接池
	private static JedisPool jedisPool = null;
	public static void initJedisPool(String IP, int port, String password)
	{
		try
		{
			JedisPoolConfig config = new JedisPoolConfig();
			config.setMaxTotal(MAX_TOTAL);
			config.setMaxIdle(MAX_IDLE);
			config.setMinIdle(MIN_IDLE);
			config.setMaxWaitMillis(MAX_WAIT);
			config.setTestOnBorrow(TEST_ON_BORROW);
			
			jedisPool = new JedisPool(config, IP, port, TIMEOUT, password);
		} 
		catch (Exception e)
		{
			e.printStackTrace();
		}
	}

	public synchronized static Jedis getConnection()
	{
		try
		{
			if (jedisPool != null)
			{
				Jedis resource = jedisPool.getResource();
				return resource;
			} else
			{
				return null;
			}
		}
		catch (Exception e)
		{
			e.printStackTrace();
			return null;
		}
	}

	public static void returnResource(final Jedis jedis)
	{
		if (jedis != null)
		{
			jedis.close();
		}
	}
	
	public static void main(String[] args)
	{
		initJedisPool("localhost",6379,null);
		Jedis redis = getConnection();
		redis.select(1);
		//redis.set("key01", "a");
		//redis.set("key02", "b");
		//redis.set("key03", "c");
		System.out.print(redis.dbSize());
		
		returnResource(redis);
	}
}

1、下载驱动
jedis驱动源码地址
jedis驱动下载地址

2、测试代码

package com.djhu.redis.test;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import redis.clients.jedis.Jedis;

public class ConnectionTest
{
	public static Jedis getConnection(String ip, int port)
	{
		Jedis jedis = new Jedis(ip, port);
		//jedis.auth("password");
		return jedis;
	}

	public static void cleanAll(Jedis jedis)
	{
		jedis.flushDB();
	}

	public static void stringTest(Jedis jedis)
	{
		jedis.set("key01", "a");
		jedis.set("key02", "b");
		jedis.set("key03", "c");
		jedis.mset("key04", "d", "key05", "e", "key06", "f");

		jedis.del("key04");
		System.out.println("key01 is " + jedis.get("key01"));
		System.out.println("key04 is " + jedis.get("key04"));
	}

	public static void mapTest(Jedis jedis)
	{
		Map<String, String> map = new HashMap<String, String>();
		map.put("username", "hansen");
		map.put("usersex", "male");
		jedis.hmset("mapkey01", map);

		map.put("username", "neohope");
		map.put("usersex", "male");
		jedis.hmset("mapkey02", map);

		map.put("username", "tuzi");
		map.put("usersex", "female");
		jedis.hmset("mapkey03", map);

		List<String> rsmap = jedis.hmget("mapkey03", "username", "usersex");
		System.out.println("query for hmget(\"mapkey03\", \"username\", \"usersex\") is " + rsmap);

		jedis.hdel("mapkey02", "usersex");
		System.out.println("query for hmget jedis.hmget(\"mapkey02\", \"username\") is "+jedis.hmget("mapkey02", "username"));
		System.out.println("query for jedis.hmget(\"mapkey02\", \"usersex\") is " + jedis.hmget("mapkey02", "usersex"));

		System.out.println("query for jedis.hlen(\"mapkey01\") is " + jedis.hlen("mapkey01"));
		System.out.println("query for jedis.exists(\"mapkey01\") is " + jedis.exists("mapkey01"));
		System.out.println("query for jedis.hkeys(\"mapkey01\") is " + jedis.hkeys("mapkey01"));
		System.out.println("query for jedis.hvals(\"mapkey01\") is " + jedis.hvals("mapkey01"));
	}

	public static void listTest(Jedis jedis)
	{
		jedis.lpush("keylist01", "a");
		jedis.lpush("keylist01", "b");
		jedis.lpush("keylist01", "c");

		System.out.println("keylist01 is " + jedis.lrange("keylist01", 0, -1));
	}

	public static void setTest(Jedis jedis)
	{
		jedis.sadd("keyset01", "01");
		jedis.sadd("keyset01", "02");
		jedis.sadd("keyset01", "03");
		jedis.sadd("keyset01", "04");
		jedis.sadd("keyset01", "05");

		System.out.println("query for jedis.smembers(\"keyset01\") is " + jedis.smembers("keyset01"));
		System.out.println("query for jedis.sismember(\"keyset01\", \"06\") is " + jedis.sismember("keyset01", "06"));
		System.out.println("query for jedis.scard(\"keyset01\") is " + jedis.scard("keyset01"));
	}

	public static void sortTest(Jedis jedis)
	{
		jedis.rpush("keylist02", "16");
		jedis.lpush("keylist02", "8");
		jedis.lpush("keylist02", "4");
		jedis.lpush("keylist02", "2");
		jedis.lpush("keylist02", "1");
		System.out.println("keylist02 is " + jedis.lrange("keylist02", 0, -1));
		jedis.sort("keylist02");
		System.out.println("after sort keylist02 is " + jedis.lrange("keylist02", 0, -1));
	}

	public static void main(String[] args)
	{
		Jedis jedis = getConnection("localhost", 6379);

		cleanAll(jedis);
		stringTest(jedis);
		mapTest(jedis);
		listTest(jedis);
		sortTest(jedis);
		setTest(jedis);
		jedis.close();
	}
}