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<JedisShardInfo>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<JedisShardInfo> shards = Arrays.asList(new JedisShardInfo("192.168.3.98", 6379) // , new JedisShardInfo("192.168.3.98", 6380)); List<JedisShardInfo> 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<JedisShardInfo>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<JedisShardInfo>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"); } }