Recently, many of my friends have gone to the mainstream large Internet companies for interviews (Alibaba, JINGdong, Meituan, Didi), and they will send me some interview questions after the interview. Some of my friends breezed through and got offers, but some came to ask me for answers.
In fact, I really didn’t plan to write this article, mainly because MY memory is not very good, unlike some people with strong memory, after the interview, they can almost write down their conversations with the interviewer. After his initial interview, in addition to remember some of the knowledge points talked about, the specific content is basically forgotten, so write this article is actually very difficult.
However, there are too many people asking me lately. In order to avoid repeating the answer and save myself some energy, I simply reply here. To be honest, I can only vaguely remember the keywords concurrency, JVM, distributed, TCP/IP, and I really can’t remember any of the details. And even if I did, and I told you, and you memorized, I still think it’s very unlikely that you’ll be asked the exact same question in an interview. And even if you’re lucky enough to be asked, memorizing it won’t necessarily help you in the interview, because if the interviewer asks you more than one question, you might as well just say no. Here to tell you about large-scale Internet enterprises interview questions.
First, Alibaba interview
Number one: What does Ali ask in the interview? (55 minutes)
1. What are the data structures that Java uses most in development?
Talk about your understanding of HashMap, basic implementation of the underlying principle, how does HashMap solve the collision problem?
Are these data structures thread-safe? If you say HashMap is thread-safe, then ask if you have a thread-safe map, and then ask the Conurren package.
3. Are you familiar with the JVM? A brief description of the class loading process. What does it do? I asked if GC and memory management are configured in Tomect
4, then ask HTTP protocol, get and POST basic difference, then TCP/IP protocol, three handshake, window sliding mechanism.
5. Which databases are used in the development? What are the storage engines? Then asked me pessimistic lock and optimistic lock problem use scenarios, distributed cluster implementation principle.
6, then asked me the working principle of SpringMVC and Mybatis, have you read the underlying source code?
Two, jingdong Finance interview
1. Dubbo timeout retry; Dubbo timeout setting
2. How to ensure the order of request execution
3, distributed things and distributed lock (do not appear negative deductions)
4. Distributed session Settings
5. Perform an operation, the first 50 times are successful and the 51st time is failed. A Roll back all the first 50 times b Submit the 51st throw exception.
6. What is the use of Zookeeper
7. JVM memory model
8. Split the database vertically and horizontally
9, how to page MyBatis; How to set up the cache; MySQL paging
Are you familiar with IO? NIO, blocking and non-blocking
11. Distributed session consistency
12. Idempotent design of distributed interface “No repeated deduction”
Iii. Meituan interview
1. Which project have you been familiar with recently? Draw the technical architecture of the project
2. What is the ratio between older and newer JVM generations?
3. Specific scenarios of YGC and FGC
What do jstack, Jmap, and jutil mean? How to troubleshoot JVM related issues online?
5. What are the specific meanings of the 5 parameters of the thread pool constructor method?
6. What if a sudden power outage occurs while a thread pool is processing services on a single machine? How to handle requests in processing and blocking queues?
7. What is the problem with using unbounded blocking queues?
8. How does the interface handle repeated requests?
9. What is the specific treatment plan?
10. How to ensure atomicity when changing shared variables?
11. Design an interface implementation class for external services to realize load balancing and sequential polling mechanism (considering concurrency) on the three hosts (1,2,3) (corresponding to different IP addresses).
To sum up, the above is to collect and share the interview questions of large Internet famous enterprises, and share them with you. I hope you can understand what is the interview questions of large Internet famous enterprises. If you feel the harvest, you can point a attention to collect and forward a wave oh, thank you for your support! Java programmer from Ali, JINGdong, Meituan interview back, these interview questions you can? (With answers)