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阿里云服务器上部署结合Nginx和tomcat做负载均衡，只能开启2个tomca

0

1

压测

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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redis客户端jedis序列化出现问题。

0

1

序列化

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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redis如何实现持久化操作，在实际应用中如何处理

2

1

redis

class="cursor-pointer"> 详细描述

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memcached服务端启动问题

1

压测

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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jmeter在linux环境下压测一直报错，按照学习资料的指令进行压测，报错，j

1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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使用 jdk 1.9 Callback 接口，提示我找不到

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1

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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在使用redis缓存时如何将业务逻辑与缓存之间解耦

1

缓存相关

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 源码

   @Override
    public User getUserById(int id) throws Exception {
        //find  cache
        Object object = jedisCache.get("user"+id);
        // if exist,return
        if (object!=null){
            return (User)object;
        }
        // if not exist,find user
        User user = userDAO.getUserById(id);
        jedisCache.set("user"+id,user);
        return user;
    }

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memcached 无法启动，监听远程ip

1

class="cursor-pointer"> 详细描述

./memcached -p 11211 -m 64m -l xxx.xxx.xxx.xxx -p 11211 -vv -u root  使用前面参数启动memcached ，其中 xxx.xxx.xxx.xxx为远程ip地址，执行前面命名无法启动memcached，进程里没有memcached，但若把远程ip去掉换为默认的本地ip，即127.0.0.1，则能启动，何解？
[root@VM_0_9_centos bin]# ./memcached -p 11211 -m 64m -l xxx.xxx.xxx.xxx -p 11211 -vv -u root
slab class   1: chunk size        96 perslab   10922
slab class   2: chunk size       120 perslab    8738
slab class   3: chunk size       152 perslab    6898
slab class   4: chunk size       192 perslab    5461
slab class   5: chunk size       240 perslab    4369
slab class   6: chunk size       304 perslab    3449
slab class   7: chunk size       384 perslab    2730
slab class   8: chunk size       480 perslab    2184
slab class   9: chunk size       600 perslab    1747
slab class  10: chunk size       752 perslab    1394
slab class  11: chunk size       944 perslab    1110
slab class  12: chunk size      1184 perslab     885
slab class  13: chunk size      1480 perslab     708
slab class  14: chunk size      1856 perslab     564
slab class  15: chunk size      2320 perslab     451
slab class  16: chunk size      2904 perslab     361
slab class  17: chunk size      3632 perslab     288
slab class  18: chunk size      4544 perslab     230
slab class  19: chunk size      5680 perslab     184
slab class  20: chunk size      7104 perslab     147
slab class  21: chunk size      8880 perslab     118
slab class  22: chunk size     11104 perslab      94
slab class  23: chunk size     13880 perslab      75
slab class  24: chunk size     17352 perslab      60
slab class  25: chunk size     21696 perslab      48
slab class  26: chunk size     27120 perslab      38
slab class  27: chunk size     33904 perslab      30
slab class  28: chunk size     42384 perslab      24
slab class  29: chunk size     52984 perslab      19
slab class  30: chunk size     66232 perslab      15
slab class  31: chunk size     82792 perslab      12
slab class  32: chunk size    103496 perslab      10
slab class  33: chunk size    129376 perslab       8
slab class  34: chunk size    161720 perslab       6
slab class  35: chunk size    202152 perslab       5
slab class  36: chunk size    252696 perslab       4
slab class  37: chunk size    315872 perslab       3
slab class  38: chunk size    394840 perslab       2
slab class  39: chunk size    524288 perslab       2
bind(): Cannot assign requested address
failed to listen on TCP port 11211: Cannot assign requested address

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redis序列化问题

0

1

redis

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

  @Override
    //单条查询
    public User findUserById(int userId) {
        ValueOperations<String, Object> vos = redisTemplate.opsForValue();

        User user = null;
        if ("".equals(vos.get(String.valueOf(userId)))){

//            (redisTemplate.opsForValue().get(String.valueOf(userId))==null)
            logger.info("\n从缓存返回空值");
            return user;
        }

        try {

            if (vos.get(String.valueOf(userId)) != null) {
                logger.info("\n" + "从缓存中查询单条数据");
                user = (User) vos.get(String.valueOf(userId));
            } else {
                logger.info("\n" + "从数据库中查询单条数据");
                user = userDao.findUserById(userId);
                if (user != null) {
                    vos.set(String.valueOf(userId), user);
                    logger.info("\n" + "新增单条缓存数据:" + vos.get(String.valueOf(userId)));
                } else {
                    vos.set(String.valueOf(userId),"", 60,TimeUnit.SECONDS);
                    logger.info("\n" + "将空值存到缓存");
                }
            }
        } catch (Throwable t) {
            t.printStackTrace();
        }
        return user;


    }

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redis缓存spring-data的使用

1

redis

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

@Autowired
	RedisTemplate redisTemplate;
	@Override
	public Integer queryWork(Integer isWork) throws Exception {
		//redis jar包自动装载方式
		ValueOperations<String, String> stringOperations = redisTemplate.opsForValue();
		String isWorks = stringOperations.get(String.valueOf(isWork));
		if (isWorks!=null){
			return Integer.parseInt(isWorks);
		}
		Integer isWork1 = dao.queryWork(isWork);
		stringOperations.setIfAbsent(String.valueOf(isWork), String.valueOf(isWork1));
		return isWork1;
	}
	@Override
	public List<Student> queryGood(Integer isGood) throws Exception {
		ListOperations<String, Object> listOperations = redisTemplate.opsForList();
		List<Student> student1 = (List<Student>) listOperations.leftPop(String.valueOf(isGood));
		logger.info("Redis中取到的结果为："+student1.toString());
		if (student1!=null){
			return student1;
		}
		List<Student> student = dao.queryGood(isGood);
		listOperations.leftPush(String.valueOf(isGood), student);
		return student;
		/*return dao.queryGood(isGood);*/
	}
	@Override
	public Student findStudentId(Integer ID)throws Exception{
		ValueOperations<String, Object> valueOperations = redisTemplate.opsForValue();
		Student student1 = (Student) valueOperations.get(String.valueOf(ID));
		logger.info("Redis中取到的结果为："+student1.toString());
		if (student1.getID()!=null){
			logger.info("Redis中取出并返回页面的结果为："+student1.toString());
			return student1;
		}
		Student student = dao.findStudentId(ID);
		/*List<Student> students = new ArrayList<student>();*/
		valueOperations.set(String.valueOf(ID),student);
		Student student1s = (Student) valueOperations.get(String.valueOf(ID));
		logger.info("存入缓存的值为："+ student1s.toString());
		return student;
	}