private TurmsRedisClient getClient(long shardKey) {
        return clients.get(shardingAlgorithm.doSharding(shardKey, clients.size()));
    }
In fact, the method is designed for {@link UserStatusService#updateOnlineUsersTtl} currently

@param keyGenerator The size of keys should not be larger than 1,048,576(1024*1024), or Redis
                    will throw
turms-server-common/src/main/java/im/turms/server/common/storage/redis/TurmsRedisClientManager.java