Redis集群的槽分配的几种实现方法

HASH_SLOT = CRC16(key) % 16384

import java.util.zip.CRC32;

public class RedisSlotCalculator {
    public static void main(String[] args) {
        String key = "exampleKey";
        int slot = getSlot(key);
        System.out.println("Key: " + key + ", Slot: " + slot);
    }

    public static int getSlot(String key) {
        CRC32 crc = new CRC32();
        crc.update(key.getBytes());
        long crcValue = crc.getValue();
        return (int) (crcValue % 16384);
    }
}

redis-cli --cluster create 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 --cluster-replicas 0

>>> Performing hash slots allocation on 3 nodes...
Master[0] -> Slots 0 - 5460
Master[1] -> Slots 5461 - 10922
Master[2] -> Slots 10923 - 16383
>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
>>> Performing Cluster Check (using node 127.0.0.1:7000)

# 在节点 127.0.0.1:7000 上执行槽迁出
redis-cli -p 7000 cluster setslot 0-1000 migrating 127.0.0.1:7001

# 在节点 127.0.0.1:7001 上执行槽迁入
redis-cli -p 7001 cluster setslot 0-1000 importing 127.0.0.1:7000

# 将槽从节点 127.0.0.1:7000 移动到节点 127.0.0.1:7001
for slot in $(seq 0 1000); do
  redis-cli -p 7001 cluster setslot $slot node $(redis-cli -p 7001 cluster myid)
done

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

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

public class RedisClusterSlotExample {
    public static void main(String[] args) {
        // 定义 Redis 集群节点
        Set<HostAndPort> jedisClusterNodes = new HashSet<>();
        jedisClusterNodes.add(new HostAndPort("127.0.0.1", 7000));
        jedisClusterNodes.add(new HostAndPort("127.0.0.1", 7001));
        jedisClusterNodes.add(new HostAndPort("127.0.0.1", 7002));

        // 创建 JedisCluster 对象
        try (JedisCluster jedisCluster = new JedisCluster(jedisClusterNodes)) {
            // 获取集群节点信息
            String clusterNodes = jedisCluster.clusterNodes();
            System.out.println("Cluster nodes:\n" + clusterNodes);

            // 获取集群槽信息
            String clusterSlots = jedisCluster.clusterSlots().toString();
            System.out.println("Cluster slots:\n" + clusterSlots);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}