Ali developed three sides, and the interviewer's set of combined punches made me confused on the spot

now 4 In the middle of the , Although the peak season of gold, silver and four has passed , However, many large factories are still in a state of shortage of personnel , Such as The ant gold dress 、 JD.COM etc. .

Some time ago , Introduced by a friend, I had the honor to interview Ali , Before the interview is a more confident state , After all, there was nothing wrong with the previous technology , In the same age, it can be regarded as the great God level . But I don't know this year Baidu What is the situation of the interview , On three sides, I was badly abused , Just hang up .

Ali side ：

• According to convention Self introduction and project introduction
• sketch hash How did the conflict happen , What are the common processing methods , stay java Occur in the hash How to get multiple conflicts after a conflict value?
• Tell me about Java GC Mechanism ?
• Red and black trees You need to compare the size to insert , What is the basis for comparison ? other Hash Conflict resolution ?
• JVM Memory model jmm Tell me all you know
• say something Java The principle of thread pooling ? What are the thread pools ? What type of thread pool does the thread pool factory have , And thread pool parameters ?
• BIO、NIO、AIO The difference and connection ?
• hash and B+ The difference between trees ? What scenarios are they applied to ? Which is better ?
• What's the concept of index and what's the use ?
• Java web Filter life cycle ?
• Tell me about TCP Three handshakes and four waves of the agreement ?
• mysql Database default storage engine , What are the advantages
• MySQL Transaction isolation level for , What problems should be solved separately .
• Talking about transaction characteristics (ACID)?
• Solution to generate unique order number under high concurrency
• Yes 10w Number How to play cpu performance Fast sum use java Realization
• What are the causes of deadlock ?
• Tomcat Class loading mechanism / J2EE In application class loader Hierarchical structure ?
• Is index scanning necessarily faster than full table scanning ? Why? ?
• stay Baidu Under the unified log system , If you do, for every request , Set a separate keyword ? In this way, you can quickly search the context through the unified log ;
• Chat spring Of IOC and AOP, What technologies are used ; In practical use , How to use ?
• Chat nosql, What are you familiar with ? for example mongodb、memcache、redis.
• Chat java Of juc frame , Be familiar with which of these classes , When did you use it , How to use ?
• Talk about jvm Your tuning strategy , If you have relevant handling experience in your work, please talk about .

Ali on both sides ：

• Introduce your own projects , The technical points 、 difficulty . Technical points about the project , We talked about ;
• TCP/IP Handshake process , Retransmit relevant knowledge ;
• TCP And UDP difference ,TCP Reliability guarantee , Congestion control and flow control ;
• Various Sort Algorithm The way 、 Time complexity ;
• Hash conflict resolution , Advantages and disadvantages ;
• De duplication in a large number of documents ;
• The difference between process and thread ;
• Process communication mode ;
• The difference between user mode and kernel mode ;
• Java Parent delegate mechanism , Break parental delegation ;
• volatile and synchronized difference ;
• Selection of database index ;
• Design patterns , The main question is about the singleton mode 、 Observer mode 、 Factory pattern and abstract factory pattern .

Three sides of Ali ：

• Introduce your own projects , The technical points , Development history ; Difficulties encountered in the development process , And troubleshooting 、 The solution ;
• Commonly used data structures ,Arraylist and Linkedlist Ergodic efficiency ;
• The usual way of learning technology , What books are you reading , The next learning direction .

Last

I also learned a lot during the interview . The feeling is quite basic , Second, it's more difficult for me , Three sides asked about some places they were not prepared to go . I don't know much about the backend , During the interview, I felt that my answer was very general, and I hung up on three sides , Purring ~ Can only accept the facts , Wait until the second half of the year . Finally, for the above frequently asked questions, I also summed up the major Internet companies java Most of the interview questions and answers involved in the programmer interview are made into documents and learning notes, and the file and structure can be taken by yourself （ Include Dubbo、Redis、Netty、zookeeper、Spring cloud、 Distributed 、 High concurrency architecture technical data ）