一.Redis的分布式

Redis本身不支持分布式，通过Jedis客户端可以实现使用Redis分布式。

package com.gqshao.redis.connection;import com.google.common.collect.Lists;import com.gqshao.redis.utils.JedisUtils;import org.junit.*;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import redis.clients.jedis.*;import java.util.Arrays;import java.util.List;/** * Jedis 独有的分布式 * 根据List
    
     中Redis顺序和key，指定固定的Redis * 扩容时使用 Pre-Sharding */public class ShardedJedisTest {    protected static Logger logger = LoggerFactory.getLogger(ShardedJedisTest.class);    private static ShardedJedisPool pool = null;    protected ShardedJedis jedis = null;    @BeforeClass    public static void createPool() {        JedisPoolConfig poolConfig = JedisUtils.getMyDefaultJedisPoolConfig();//        List
     
       shards = Arrays.asList(new JedisShardInfo("192.168.3.98", 6379)//                , new JedisShardInfo("192.168.3.98", 6380));        List
      
        shards = Lists.newArrayList();        JedisShardInfo info1 = new JedisShardInfo("192.168.3.98", 6379);        JedisShardInfo info2 = new JedisShardInfo("192.168.3.98", 6380);        // 添加的顺序有意义        shards.add(info1);        shards.add(info2);        pool = new ShardedJedisPool(poolConfig, shards);    }    @Before    public void getResource() {        jedis = pool.getResource();    }    @After    public void destroyJedis() {        pool.returnResource(jedis);    }    @AfterClass    public static void destroyPool() {        pool.destroy();    }    /**     * 不同的key分配根据List
       
        中的顺序，分配不同的Redis连接     */    @Test    public void testSet() {        for (int i = 0; i < 20; i++) {            try {                logger.info(i + " - " + jedis.getShard("" + i).getClient().getHost()                        + " : " + jedis.getShard(i + "").getClient().getPort());                logger.info(jedis.set("" + i, "true"));            } catch (Exception e) {                e.printStackTrace();            }        }    }    /**     * 修改List
        
         中的顺序，无法得到结果，确定该顺序是有意义的     */    @Test    public void testGet() {        for (int i = 0; i < 20; i++) {            try {                logger.info(i + " - " + jedis.getShard(i + "").getClient().getHost()                        + ":" + jedis.getShard(i + "").getClient().getPort() + " ? " + jedis.get("" + i));            } catch (Exception e) {                e.printStackTrace();            }        }    }}
        
       
      
     
    

二.Redis主从复制

redis的主重复制有两种方式，第一种是写在.conf配置文件中，第二种是通过命令slaveof ip port 或 slaveof no one

slaveof no one 之后，当前Redis节点提升为Master但之前数据不会丢失，所以通过程序动态的设置主从复制可以解决Redis单点故障的问题

package com.gqshao.redis.connection;import com.gqshao.redis.utils.JedisUtils;import org.junit.*;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import redis.clients.jedis.Jedis;import redis.clients.jedis.JedisPool;import redis.clients.jedis.JedisPoolConfig;/** * slaveof 和 slaveofNoOne方法可以在运行中动态设置服务器为Master或Slave */public class SlaveofTest {    protected static Logger logger = LoggerFactory.getLogger(SlaveofTest.class);    private static JedisPool pool1 = null;    protected Jedis jedis1 = null;    private static JedisPool pool2 = null;    protected Jedis jedis2 = null;    @BeforeClass    public static void init() {        JedisPoolConfig poolConfig = JedisUtils.getMyDefaultJedisPoolConfig();        // timeout设置为0，解决JedisConnectionException        pool1 = new JedisPool(poolConfig, "192.168.3.98", 6379, 0);        pool2 = new JedisPool(poolConfig, "192.168.3.98", 6380, 0);        logger.info("----------------------create resource----------------------");    }    @AfterClass    public static void destroy() {        pool1.destroy();        pool2.destroy();    }    @Before    public void initJedis() {        jedis1 = pool1.getResource();        jedis2 = pool2.getResource();    }    @After    public void destroyJedis() {        pool1.returnResource(jedis1);        pool2.returnResource(jedis2);    }    /**     * 测试主从复制 注意设置Slave之后需要时间复制数据     */    @Test    public void test() {        // 设置 Redis2为Redis1的slave        logger.info("jedis1 slaveof no one");        jedis1.slaveofNoOne();        logger.info("jedis2 slaveof 192.168.3.98 6379");        jedis2.slaveof("192.168.3.98", 6379);        try {            jedis2.set("key", "value");        } catch (Exception e) {            logger.warn("由于设置的原因slave为read only");        }        // 主从复制 Redis1中保存数据Redis2中可以读取        logger.info("jedis1.set mykey1 myvalue1 : " + jedis1.set("mykey1", "myvalue1"));        try {            Thread.sleep(1000);        } catch (InterruptedException e) {            e.printStackTrace();        }        logger.info("jedis2.get mykey1: " + jedis2.get("mykey1"));        // 单点问题解决思路(思路启用Redis2为Master，Redis1为SlaveOf Redis1)        // 提升Redis2为Master，读取刚才的数据，重启Redis1，将Redis2设置为Redis1的Master        jedis2.slaveofNoOne();        // 测试值仍然存在        logger.info("jedis2.get again : " + jedis2.get("mykey1"));        // Redis2中存入数据        logger.info("jedis2.set mykey2 myvalue2 : "+jedis2.set("mykey2", "myvalue2"));        // Redis1设置为Redis2的slave        jedis1.slaveof("192.168.3.98", 6380);        try {            Thread.sleep(1000);        } catch (InterruptedException e) {            e.printStackTrace();        }        // 测试jedis1中读取数据        logger.info("jedis1.get mykey2 : " + jedis1.get("mykey2"));        logger.info("jedis1 slaveof no one");        jedis1.slaveofNoOne();        jedis1.del("mykey1", "mykey2");        jedis2.del("mykey1", "mykey2");    }}