Recently, some fans complained to me backstage , Go to a large factory for interview , Interviewers always like to ask JVM!
You ask JVM Why? ? Programmers usually don't use these things ! Ask more about the framework , database , Project experience is not good ?
Some people think it's the interviewer who pretends to be forced , I like to ask such empty but not real things , Look like you're tough , Force the company !
In fact, this idea is very naive ! I don't rule out that some interviewers have this idea , I like interviewing and abusing people . But big factories have big concerns , ask JVM It's mainly about your potential in technology , Do you think you have a deep attitude towards technology .
Probably in 2011 About , Alipay has had multiple memory leaks. , And the problem is quite serious , At that time, master bixuan personally led the team to solve the problem . here we are 2013 About , Ali's rapid development , Many architectures are based entirely on OSGI,
JVM More and more prominent problems , If you don't understand JVM There is no way to do it , So from then on ,JVM It has become the technical requirement of Ali .
There is a more important reason , Right now Java Development post , Competition too TM It's intense !
Some time ago , Our director will recruit one Java back-end , Two days 200 Multiple resumes ! So many resumes can't be screened out !
Generally, only one or two people are recruited for the posts in large factories , There are 10 personal , The technical ability is almost the same , Who do you say you will choose at this time ?
If I were an interviewer , I'll ask who will JVM performance tuning ? Who will , The better the technical ability, the better !BAT That's it , Many small companies like to follow suit , So don't ask questions JVM I'm sorry to say hello to other people . therefore ,JVM Very important , Be able to have JVM Tuning skills are more important .
Take a look at these real questions of Ali's interview , Can you answer ?
1,JVM What are the memory areas ? Why is this division ?
2,GC Roots What are there ? The more comprehensive, the better .
3, A 100 million class flow system , Let it hardly happen Full GC. You do it JVM tuning , How do you do it? ?
4, Online system suddenly CPU100%, How do you check it out ?
4,JVM The difference between memory leak and memory overflow , How to check memory leak ?
These problems , from the shallower to the deeper , It has to be right JVM Have a systematic understanding and learning , To be able to answer , And basically, all the questions are combined with the actual situation , Not only do you need to be able to use these technologies , Also know why you want to use this technology , And how to achieve high availability and so on . To master JVM, There is a high demand for the breadth and depth of the programmer's technology .
JVM Class loading is included in the system of , Runtime data area , Bytecode execution engine , Garbage recovery and other aspects , If there is a problem with your app , You may need to investigate from many aspects , This is the breadth of technology ;
meanwhile JVM Many of the problems in , It's hidden deep , It is possible that a line of garbage code will cause a memory leak and cause a system failure OOM, To solve this problem requires technical depth ;
In order to let everyone have a targeted upgrade technology , Before my special invitation 58 architect King The teacher brought it to you 《JVM Deep analysis of infrastructure and performance tuning 》 Live class , from
JVM memory management , The running process of bytecode , Garbage collection mechanism , 100 million class flow system GC Prediction and optimization ,CPU High occupancy and tuning practice ,JVM Memory tuning and so on , Make your promotion and job hopping more confident !
7.14 Interview must ask JVM Deep analysis of bottom layer principle
Quick Mastery JVM memory management ;
How to analyze the running process of bytecode through stack frame ;
depth analysis JVM Garbage collection mechanism ;
100 million class flow system GC Prediction and optimization ;
7.15 One of the necessary skills for Architects JVM Optimize actual combat
JVM Necessary foundation and theory before optimization ;
JVM Common problems positioning and tool use ;
Analysis of architecture skills CPU High occupancy and memory overflow ;
One of the necessary skills for Architects JVM Optimize actual combat ;
Front 58, Senior architect of China Merchants Bank ,10 one 's remaining years java Industry experience .
Specialized field ： Software architecture design , High concurrency , High performance services ;
Suitable for people
This sharing content partial principle and the source code , There needs to be some Java Basic knowledge , fit ：
Have certain self-study ability , Want to improve yourself ;
Want to learn systematically JVM Knowledge partner ;
Aspire to be a senior engineer , Architect's IT people ;
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The main contents of this interview manual are as follows 3 primary topic ,5 Main modules ,35 Small plates ：
Programmer interview question set ：
JAVA Core interview question bank （1000+ topic .pdf） JAVA Common interview question bank （3000+ topic .pdf） BATJ JAVA Interview question bank of classic compulsory examination （50+ topic .pdf）
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Concurrent programming , Multithreading , Collection framework , Design patterns , database , performance optimization RabbitMQ Message middleware ActiveMQ Message middleware Dubbo JVM Kafka MongoDB
MyBatis MySQL Netty Nginx Redis Tomcat Zookeeper Spring SpringBoot SpringCloud
Programmer's essential book list （ Massive collection Edition ）
Programmer Resume Template （900 share ）
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