The latest Java interview experience and interview questions in October 2020 (one-time check for vacancies to make up for enough), I believe that many people are preparing for the interview, how to get the offer you want, enter the dream big factory, and realize your career ideals , To reach the well-off level of programmers.
Share a Java interview information. Due to the length of the article, it is impossible to display all the interview questions in text format. This article has selected some interview questions for everyone. If you need this full version of the interview notes To get the interview information, just: click here to get it!!! Password: CSDN
The first (Zookeeper + microservices + message middleware + high concurrency architecture design)
one side
JVM data storage model, the structure of the new generation and the old generation?
Java GC algorithm, when will minor gc be triggered and when will full gc be triggered?
Which of the GC reachability analysis is considered GC ROOT?
JVM tuning parameters you are familiar with, and which tuning tools have you used?
What types of locks does Java have?
Describe the processing flow of the thread pool?
Class loading mechanism. There are several steps for loading a class into a virtual machine. Which of these steps are fixed in order and which is not fixed, why not?
Hashmap is not thread-safe, and concurrenthashmap is thread-safe. How to achieve thread-safety?
What problem does the volatile keyword solve, and what is the implementation principle?
What are the concurrent containers and the difference between concurrent and synchronous containers
Two sides
At work, the optimization of SQL statements and matters needing attention
Which libraries or frameworks use NIO
What kinds of injection methods does Spring have, which ones to use under what circumstances, and the principle of ioc implementation
How to locate a slow query, how do you quickly locate a service with multiple SQL
Do you know clustered index and non-clustered index? When to use a clustered index and what to use a non-clustered index
What storage structure does Nosql engine use, what are the advantages and disadvantages of relational database and NoSQL, and how to select the technology?
Under the microservice architecture, if there is an order system and an inventory system, how to guarantee transactions?
Distributed consensus protocol raft, do you understand paxos
ZAB protocol in Zookeeper, main selection algorithm
Three sides
Self introduction
Participate in concurrent projects, from design to deployment, follow the process to repeat.
You have used redis for project-related purposes. In what scenarios and how did you use it?
The principle of mysql synchronization mechanism, what are the synchronization methods
How to realize database master-slave synchronization and how to realize transactions
Talk about your understanding of SOA and microservices, as well as the adjustments and challenges involved in distributed architecture from the application level.
What are the similarities and differences between Ali-based middleware metaQ and its principles and existing Kafka
Do you know any middleware in Ali? Implementation principle? What are the characteristics of other open source message queues?
Why choose to change company?
Career planning for three to five years?
Do you want to ask me?
The second (phantom reading + segment lock + Spring Cloud + spike)
one side
Brief introduction
ACID of the transaction, which explains the isolation of the transaction in detail
Dirty reading, phantom reading, non-repeatable reading
Red-black tree, binary tree algorithm
Which collection classes are commonly used? What is the difference between ArrayList and LinkedList? The internal data structure of HashMap? ConcurrentHashMap segment lock?
What optimizations have been made to hashMap and concurrentHashMap in jdk1.8
How to resolve the hash conflict, and if there is a conflict, how to find the target value in the hash table
The difference between synchronized and ReentranLock?
ThreadLocal? Application scenario?
Java GC mechanism? What are the GC Roots?
Will there be deadlocks in MySQL row locks?
Two sides
Do you understand optimistic locking and pessimistic locking? What is involved in optimistic locking and pessimistic locking in JDK?
Nginx load balancing strategy?
Have you compared Nginx with other load balancing frameworks?
Is Redis single threaded?
The reason for the high concurrency of Redis?
How to use Redis to process hot data
Talk about Redis sentinel, replication, cluster
What technology has been optimized at work? Talk about JVM, MySQL, code, etc.
Three sides
What does Spring Cloud use? How to achieve load balancing? How to judge if the service is down?
Network programming nio and netty related, netty thread model, zero copy implementation
What do you know about the implementation of distributed locks? Talk about an implementation method in detail
In high-concurrency application scenarios, what does the technology need to involve? How to design the architecture?
Next to the issue of high concurrency, it talked about the technical applications of spikes: kafka, redis, mycat, etc.
Finally, talk about the projects you have participated in, those with relatively high technical content, related architecture design and what core coding you are responsible for
Third house
One side (50 minutes)
Hashmap, how to expand, how to deal with data conflicts? How to efficiently implement data migration?
How to implement Linux shared memory, probably talk about it.
Socket network programming, talk about TCP's three-way handshake and four waved hands
What is the difference between synchronous IO and asynchronous IO?
Java GC mechanism? What are the GC Roots?
Red-black tree talk about five features, insert and delete operations, time complexity?
The time complexity of fast sorting, the worst case, the best case, the time complexity of heap sorting, and the complexity of building a heap
Two sides (40 minutes)
Introduce yourself, mainly talk about what you have done and what you are good at
What do you know about design patterns?
How does AtomicInteger realize atomic modification?
What is the difference between ConcurrentHashMap in Java7 and Java8? Why is Java 8 concurrency more efficient? When to use--
HashMap, when to use ConcurrentHashMap?
Redis data structure?
Redis data elimination mechanism?
Three sides (about 1 hour)
The principle of mysql to achieve transaction (MVCC)
How is MySQL data master-slave synchronization achieved?
The realization of MySQL index, innodb index, how to realize the b+ tree index, why use b+ tree as index node, one node is saved
How much data, how to specify the size, corresponding to the disk page.
If Redis has 100 million keys, will using the keys command affect online services?
Redis persistence methods, aod and rdb, how to implement it, append logs and backup files, do you know the underlying implementation principle?
What is the biggest difficulty encountered? How to overcome?
What is the future plan?
What do you want to ask me?
The fourth (transaction + cluster + spike architecture)
one side
The difference and applicable scenarios of common collections
What do concurrent containers know?
How to judge whether the linked list has a ring
How to implement concurrentHashMap
How cluster servers share application
JAVA network programming: the difference and connection between BIO, NIO and AIO
Jvm memory model jmm knows all about
JAVA garbage collection, the difference between the marking algorithm and the copy algorithm, what occasions are they used for?
The difference between http and https, the difference between http1.x and http2.0, the difference between SSL and TSL
The difference between GC, G1 and ZGC
The difference between B+ tree and B tree, and the difference between red and black trees
The difference between memory leak and memory overflow
How long is the life cycle of the session
How much do you know about the Mina framework? (Because I used Mina in the project, I mentioned this part)
Two sides
java cas principle
What are the parameters of the JAVA thread pool, and what issues should be considered if you design a thread pool by yourself?
The underlying implementation of Java's lock?
What are the advantages of mysql database default storage engine
MySQL's transaction isolation level, what problems are solved respectively.
Four tables record grades, each with about 100,000 records, how to find the students with the best grades
What are the common load balancing algorithms
If Redis has 100 million keys, will using the keys command affect online services?
Redis persistence methods, aod and rdb, how to implement it, append logs and backup files, do you know the underlying implementation principle?
Three sides
Please draw a distributed server cluster deployment diagram of a complete large-scale website
Multiple RPC requests come in, how does the server handle concurrency?
Talk about the sentinel mechanism of Redis
How much data does the database sub-database sub-table generally need?
How to ensure that the database is consistent with the redis cache
How is the message queue used in the project? What specific business scenarios are used?
Which JVM-related analysis tools have you used? Are there specific performance tuning steps?
How to do MySQL slow sql optimization in general? Besides, what other methods are there to optimize?
Online server monitoring indicators, which indicators do you think need the most attention? why?
How to do stress testing, anti-stress methods
How to design the spike module
HR face
Self introduction
How would you rate your previous 3 interviews
What do you think of yourself, what is your biggest core competitiveness
Future career plan
What kind of understanding of Ali's technology atmosphere, and which Ali's open source libraries have been used
What is the expected salary
Finally, what do you want to know
Interview Question Answer
Alright guys, this is the end of this article! Regarding why the answers to the interview questions are not written directly, what I want to say is that writing the interview questions will make the article look very long (it is already very long...) This will affect the readability of the article.
Now I have compiled more than 1,000 java interview questions from multiple companies and more than 400 pages of pdf documents, all of which have been organized by topic. There are hundreds of pages of Java core knowledge points PDF. Due to the length of the article, it is impossible to display all the interview questions in text form. This article has selected some interview questions for everyone. If you need this full version of the interview notes, you only need to obtain the interview information: Click here to receive!!! Password: CSDN