Interview Reply of Zhuhai Jinshan

Delivery post

senior Java Development , requirement 3 To 5 Years of experience , The resume was rejected by the business party once because of its short working experience , Has been HR Pick it up after one recommendation .

Interview question memory

one side 1.15 Hours

project
How to realize the bottom layer of fusing
What else can a semaphore do besides limiting current
The principle of rough and fine arrangement

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redis
cluster colony
How to keep in sync
redis RDB Can you continue the transmission at breakpoints
Cache penetration ？
How to realize the bottom layer of Bloom filter ？
Bottom bitmap, Calculate the position in the array through the hash function （ hash function + Array ）.
bitmap How big is the largest ？
How to save the data of onebillion users ？ How to split ？
Consistent Hashing

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mysql
How to optimize the database ？
The bottom layer of the leftmost match , Why the leftmost match ？
How to realize optimistic lock and pessimistic lock in database ？

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es
es How to find the full text quickly ？
es How to ensure high availability
es Why can't I change it after I set the partition for the first time ？
hash function
How to write in a stand-alone ？
flush What happens if I hang up before operation ？
translog,fsyn Default 5 Second drop , It can also be manually set to drop the disc every time

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computer network
https How is the process ？
https How to certificate ？
How to authenticate non encrypted algorithms ？
How to prevent middlemen from changing ？

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java
JVM tuning ？
Will meta space be automatically expanded ？
The elderly generation guarantee ？
How to maintain consistency in high concurrency ？
synchronize Bottom
synchronize Lock down
lock and synchronize
Let's talk about AQS
AQS What design patterns are used
CAS
ABA problem
seen JDK Source code is not ？
HashMap Why dead circulation
ConcurrentHashMap
sleep and wait
run and start
Thread pool parameters ？
How to maximize the number of active threads ？
What will happen if you change the order , Don't block the queue , Directly add to the maximum thread ？

Analysis and summary

The answer to the question is ok ,80% It's all answered . And talked for more than an hour , I think it's OK , The result was still hung up . I haven't slept well for two days , Carefully recall the reasons .

First , The project talks too much , For the first time in a long time , Too little interview experience , I don't speak fluently . The interviewer began to say , Talk about a project with the highest participation , I talked about search collateral without thinking about it , Because I did it all by myself , So participation 100%. There are also some questions in the middle , Have answered . I think we will talk about the most complex projects later , The results did not , Start asking for eight part essay directly . It is estimated that the project I started talking about is too simple , Don't ask anything else directly behind . My colleague listened and said , What is there to say about the collateral branch , There is no gold content . It's all about minus points , Then delete this part directly . It's also the problem of too little interview experience , I can't feel what the interviewer feels and wants to hear , I didn't think I would hang up , As a result, I didn't feel it until I experienced it .

in addition , Chatting too casually , Not proactive enough . In fact, I didn't mention the project in the end , You should take the initiative to say ：” Although this project has a high degree of participation , But the complexity is not enough , The logic is simple , Not enough to show my work , Can I talk more about the main process of search ？“ You can't wait for the interviewer to ask , Have a bright spot to show yourself , And we must show it ！ Can't feel almost on the line , Wait until you get a chance next time , This can easily lead to no next time . It can't be similar , Be sure to completely . Don't think about boasting about your ability and be embarrassed to say it . If you don't talk, you'll hang up , Should hold such a mentality , It's true . At that time, I just thought it was almost the same whether I said it or not , This idea can't exist anymore , Don't talk about the best project at first , Don't make a good impression , It's hard to recover .

And if you talk a lot about the project , There is less time left for the interview to ask eight part essay , Further reduce the fault tolerance . As long as the interviewer doesn't stop , We should talk about as many projects as possible , At least tell the highlights of your work . Otherwise, the project you talked about is general , The answer is also average , It must be gone . At least we should support the part of the project first .

But I calmed down and thought again , Maybe the result has been decided by my working years . Unless it's really good , But I was too implicit to be particularly excellent , Therefore, the original judgment is upheld . There may also be more suitable competitors , Or suddenly no HC 了 , Various possibilities . I can only say that we should sum up more experience , Learn from it .

Some people say we should order something else first , Accumulate some experience , Come again, the one you want to go most . But this opportunity is really waiting for no one , I happened to meet someone who was hiring , It's also appropriate , See it again today , The recruitment information has been dropped . It's a pity , I still didn't seize every opportunity to express myself , Did not show a strong desire to succeed .

Last , Let's conclude with a sentence from the Celtic training hall , Mutual encouragement ！