redis 集群批量操作實(shí)現

 Redis集群是沒(méi)法執行批量操作命令的，如mget，pipeline等。這是因為redis將集群劃分為16383個(gè)哈希槽，不同的key會(huì )劃分到不同的槽中。但是，Jedis客戶(hù)端提供了計算key的slot方法，已經(jīng)slot和節點(diǎn)之間的映射關(guān)系，通過(guò)這兩個(gè)數據，就可以計算出每個(gè)key所在的節點(diǎn)，然后使用pipeline獲取數據。具體代碼如下：

初始化    JedisCluster類(lèi)

@Configuration
public class JedisClusterConfig {

    @Value("${spring.redis.cluster.nodes}")
    private String clusterNodes;

    @Value("${spring.redis.cache.commandTimeout}")
    private Integer commandTimeout;

    @Bean
    public JedisCluster getJedisCluster() {

        String[] serverArray = clusterNodes.split(",");
        Set<HostAndPort> nodes = new HashSet<>();
        for (String ipPort : serverArray) {
            String[] ipPortPair = ipPort.split(":");
            nodes.add(new HostAndPort(ipPortPair[0].trim(), Integer.valueOf(ipPortPair[1].trim())));
        }
        return new JedisCluster(nodes, commandTimeout);
    }
}

工具類(lèi) JedisClusterUtil

@Component
public class JedisClusterUtil {

    @Autowired
    private JedisCluster jedisCluster;

    @Resource(name = "redisTemplate4Json")
    protected RedisTemplate<String, Object> redisTemplate;

    /**
     * ZSet批量查詢(xún)
     * @param keys
     * @return
     */
    public List<Object> batchZRange(List<String> keys) {

        List<Object> resList = new ArrayList<>();
        if (keys == null || keys.size() == 0) {
            return resList;
        }

        if (keys.size() == 1) {
            BoundZSetOperations<String, Object> operations = redisTemplate.boundZSetOps(keys.get(0));
            Set<Object> set = operations.reverseRange(0, 0);
            resList.add(set.iterator().next());
            return resList;
        }

        Map<JedisPool, List<String>> jedisPoolMap = getJedisPool(keys);

        List<String> keyList;
        JedisPool currentJedisPool = null;
        Pipeline currentPipeline;
        List<Object> res = new ArrayList<>();
        Map<String, Object> resultMap = new HashMap<>();

        //執行
        for (Map.Entry<JedisPool, List<String>> entry : jedisPoolMap.entrySet()) {
            Jedis jedis = null;
            try {
                currentJedisPool = entry.getKey();
                keyList = entry.getValue();
                //獲取pipeline
                jedis = currentJedisPool.getResource();
                currentPipeline = jedis.pipelined();
                for (String key : keyList) {
                    currentPipeline.zrevrange(key, 0, 0);
                }
                //從pipeline中獲取結果
                res = currentPipeline.syncAndReturnAll();
                currentPipeline.close();
                for (int i = 0; i < keyList.size(); i++) {
                    if (null == res.get(i)) {
                        resultMap.put(keyList.get(i), null);
                    } else {
                        Set<Object> set = (Set<Object>) res.get(i);
                        if (null == set || set.isEmpty()) {
                            resultMap.put(keyList.get(i), null);
                        } else {
                            byte[] byteStr = set.iterator().next().toString().getBytes();
                            Object obj = redisTemplate.getDefaultSerializer().deserialize(byteStr);
                            resultMap.put(keyList.get(i), obj);
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                returnResource(jedis, currentJedisPool);
            }
        }
        resList = sortList(keys, resultMap);
        return resList;
    }

    /**
     * Value批量查詢(xún)
     * @param keys
     * @return
     */
    public List<Object> batchGet(List<String> keys){
        List<Object> resList = new ArrayList<>();
        if (keys == null || keys.size() == 0) {
            return resList;
        }

        if (keys.size() == 1) {
            BoundValueOperations<String, Object> operations = redisTemplate.boundValueOps(keys.get(0));
            resList.add(operations.get());
            return resList;
        }

        Map<JedisPool, List<String>> jedisPoolMap = getJedisPool(keys);

        List<String> keyList;
        JedisPool currentJedisPool = null;
        Pipeline currentPipeline;
        List<Object> res = new ArrayList<>();
        Map<String, Object> resultMap = new HashMap<>();

        for (Map.Entry<JedisPool, List<String>> entry : jedisPoolMap.entrySet()) {
            Jedis jedis = null;
            try {
                currentJedisPool = entry.getKey();
                keyList = entry.getValue();
                //獲取pipeline
                jedis = currentJedisPool.getResource();
                currentPipeline = jedis.pipelined();
                for (String key : keyList) {
                    currentPipeline.get(key);
                }
                //從pipeline中獲取結果
                res = currentPipeline.syncAndReturnAll();
                currentPipeline.close();
                for (int i = 0; i < keyList.size(); i++) {
                    if (null == res.get(i)) {
                        resultMap.put(keyList.get(i), null);
                    } else {
                        byte[] byteStr = keyList.get(i).toString().getBytes();
                        Object obj = redisTemplate.getDefaultSerializer().deserialize(byteStr);
                        resultMap.put(keyList.get(i), obj);
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                returnResource(jedis, currentJedisPool);
            }
        }
        resList = sortList(keys, resultMap);
        return resList;
    }

    private Map<JedisPool, List<String>> getJedisPool(List<String> keys){
        //JedisCluster繼承了BinaryJedisCluster
        //BinaryJedisCluster的JedisClusterConnectionHandler屬性
        //里面有JedisClusterInfoCache，根據這一條繼承鏈，可以獲取到JedisClusterInfoCache
        //從而獲取slot和JedisPool直接的映射
        MetaObject metaObject = SystemMetaObject.forObject(jedisCluster);
        JedisClusterInfoCache cache = (JedisClusterInfoCache) metaObject.getValue("connectionHandler.cache");
        //保存地址+端口和命令的映射
        Map<JedisPool, List<String>> jedisPoolMap = new HashMap<>();

        JedisPool currentJedisPool = null;
        List<String> keyList;
        for (String key : keys) {
            //計算哈希槽
            int crc = JedisClusterCRC16.getSlot(key);
            //通過(guò)哈希槽獲取節點(diǎn)的連接
            currentJedisPool = cache.getSlotPool(crc);

            //由于JedisPool作為value保存在JedisClusterInfoCache中的一個(gè)map對象中，每個(gè)節點(diǎn)的
            //JedisPool在map的初始化階段就是確定的和唯一的，所以獲取到的每個(gè)節點(diǎn)的JedisPool都是一樣
            //的，可以作為map的key
            if (jedisPoolMap.containsKey(currentJedisPool)) {
                jedisPoolMap.get(currentJedisPool).add(key);
            } else {
                keyList = new ArrayList<>();
                keyList.add(key);
                jedisPoolMap.put(currentJedisPool, keyList);
            }
        }
        return jedisPoolMap;
    }

    private List<Object> sortList(List<String> keys, Map<String, Object> params) {
        List<Object> resultList = new ArrayList<>();
        Iterator<String> it = keys.iterator();
        while (it.hasNext()) {
            String key = it.next();
            resultList.add(params.get(key));
        }
        return resultList;
    }

    /**
     * 釋放jedis資源
     *
     * @param jedis
     */
    public void returnResource(Jedis jedis, JedisPool jedisPool) {
        if (jedis != null && jedisPool != null) {
            jedisPool.returnResource(jedis);
        }
    }

 注意：一定要完成后釋放 jedis 資源  不然會(huì )造成卡死現象

到此這篇關(guān)于redis 集群批量操作實(shí)現的文章就介紹到這了,更多相關(guān)redis 集群批量操作內容請搜索腳本之家以前的文章或繼續瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！