From 0 to 1, Alibaba customized version of JVM master actual combat list, depth and breadth are closely linked

Beginning in 2016, it was still in the ant middleware team, and gradually had the opportunity to solve some JVM problems. Later, because of the love of JVM, mainly because of curiosity, I joined the Ali JVM team and started to face the entire Ali engineers. The road to JVM was unexpectedly out of control. I started a business and did some things related to JVM.

Recently, I specially prepared some small gifts for my friends

This time we specially prepared a series of tutorials on JVM parameter learning for everyone. I hope you can really overcome the JVM parameters, so we named the master actual combat series. Welcome everyone to forward

first part

1. JVM optimization combat, the eternal pain in the hearts of the majority of Java engineers
2. —Explore it: How does the Java code we write run?
3. Can you resist the fierce fire from the interviewer for the JVM class loading mechanism?
4. Dachang Interview Questions: What are the memory areas in the JVM and what are they used for?
5. What is the garbage collection mechanism of JVM used for? Why garbage collection
6. Draw a schematic diagram of the overall operation of the JVM without any information

 

 

the second part

1. Talk about VM generation model: young generation, old generation, permanent generation
2. Dachang interview question: How to allocate your objects in JVM memory? How to transfer
3. Hands-on experiment: personally experience how to set the JVM memory size during online system deployment
4. Case combat: How to set the JVM heap memory size in a payment system with millions of transactions per day
5. Actual case: How to set the JVM stack memory and permanent generation size for the payment system with millions of transactions per day
6. See how your online system sets the JVM memory size

 

 

the third part

1. Dachang Interview Question: Under what circumstances will an object in JVM memory be garbage collected
2. Dachang interview questions: Which garbage collection algorithms are there in JVM, and the advantages and disadvantages of each algorithm
3. Dachang interview questions: What kind of garbage collection algorithm is suitable for the young generation and the old generation
4. Dachang interview questions: What are the common garbage collectors in JVM and what are their characteristics?
5. "Stop the World" problem analysis: the most helpless pain point of JVM
6. Draw a schematic diagram of various garbage collection algorithms and garbage collectors by yourself

 

 

fourth part

1. Step by step: Demystifying how the young generation of VM's garbage collector ParNew works
2. —Step-by-step: When the old JVM garbage collector CMS worked, what did it do internally?
3. Hands-on experiment: How to set garbage collection related parameters when deploying the system online
4. Case combat: How to optimize the garbage collection parameters of the young generation in an e-commerce system with hundreds of millions of requests per day
5. Actual case: How to optimize the garbage collection parameters of the old age in an e-commerce system with hundreds of millions of requests every day
6. Take a look at how your online system sets VM garbage collection parameters? Is the setting reasonable?

 

 

the fifth part

1. Dachang Interview Question: Can you talk about the working principle of the latest G1 garbage collector
2. In-depth illustration of the principle of G1 generational recovery: why the recovery performance is better than traditional GC
3. Hands-on experiment: How to set parameters if G1 garbage collector is used for online system deployment
4. Case combat: How to optimize performance based on G1 garbage collector for an online education platform for millions of users (Part 1)
5. Case combat: How to optimize performance based on G1 garbage collector for an online education platform for millions of users (Part 2)
6. How to set JVM parameters when you have developed a system and are ready to deploy it online

 

 

the sixth part

1. bad! The running online system is suddenly stuck and cannot be accessed, the evil JVM GC
2. Dachang Interview Question: Explain what is Young GC and Full GC
3. Dachang interview questions: Under what circumstances will Young GC and Full GC happen
4. Case combat: How frequently Young GC occurs in a BI system with 100,000 concurrent times per second
5. Actual case: Why does Full Gc happen frequently with the real-time analysis engine with tens of billions of data per day
6. Open your mind! If your online system pressure increases by 100 times, will there be frequent GC problems?

 

 

Part Seven

1. Hands-on experiment: Do it yourself to simulate the frequent Young GC scene experience
2. Hardcore skills of senior engineers: how to look at the Young GC log of JVM
3. Hands-on experiment: simulate the scene of the object entering the old age by yourself (part 1)
4. Hands-on experiment: Do it yourself to simulate the scene of the object entering the old age and experience it (below)
5. Hardcore skills of senior engineers: how to look at the JVM Full GC log
6. Try to analyze it yourself—take the JVM GC log of your online system

 

 

Part Eight

1. Hands-on experiment: Use jstat to find out the VM running status of the online system
2. Hands-on experiment: use jmap and jhat to find out the object distribution of the online system
3. From testing to online: how to analyze the JVM running status and reasonably optimize
4. Case combat: How to locate and solve frequent Young GC problems with a BI system with 100,000 concurrent times per second
5. Case combat: How to locate and solve frequent Full GC problems with a real-time analysis engine with tens of billions of data per day

 

 

Part 9

1. Case study: How to optimize the GC performance of social apps with 100,000 QPS per second and increase 3 times
2. Actual case: How to optimize Full GC in the background system of vertical e-commerce APP
3. Case actual combat: how does the novice engineer set the JVM parameters unreasonably and cause frequent Full GC
4. Case actual combat: an online system dozens of full GC per day optimization results in frequent freezes
5. Case actual combat: under the e-commerce promotion campaign, serious Full GC caused the system to directly freeze optimization combat

 

 

Part ten

1. Case actual combat: memory leak and Full GC optimization caused by an online promotion campaign
2. Case combat: Optimization of frequent Full GC problems caused by millions of data misprocessing
3. Periodic review: Do you really understand the principles of JVM operation and GC?
4. Periodic review: how to do JVM performance optimization
5. How to prepare for your interview a case of JVM optimization in your own system

 

 

Part eleven

1. The nightmare of Java programmers: The online system suddenly hangs, and the terrible OOM memory overflows
2. Dachang interview questions: What is a memory overflow? In which areas will memory overflow occur
3. How does the Metaspace area have memory overflow due to too many classes
4. How does the unlimited calling method make the thread stack memory overflow
5. Too many objects! Heap memory really can’t fit, only memory overflow
6. Hands-on experiment: simulate the memory overflow of JVM Metaspace by yourself and experience it
7. Hands-on experiment: simulate the memory overflow of the JVM stack by yourself and experience it (on)
8. Hands-on experiment: simulate the scene of JVM heap memory overflow by yourself (below)

 

 

Part Twelve

1. Actual case: How can a huge data processing system be overwhelmed by OOM
2. Case actual combat: how two novice engineers mistakenly wrote code leading to OOM
3. How to monitor and alarm the OOM abnormality of the online system
4. A key question: How to automatically dump memory snapshots when JVM memory overflows
5. Hands-on experiment: How to solve the problem of memory overflow in Metaspace area
6. Hands-on experiment: How to solve when the JVM stack memory overflows
7. Hands-on experiment: What to do when JVM heap memory overflows
8. Case combat: Why does a system with only hundreds of requests per second crash due to OOM
9. Actual case: How does the NIO mechanism of the Jetty server cause off-heap memory overflow
10. Case actual combat: OOM troubleshooting practice caused by an RPC call under a microservice architecture
11. Case combat: A practice of troubleshooting OOM problems caused by SQL statements without WHERE conditions

 

 

Part 13

1. Case actual combat: OOM problem troubleshooting practice of log analysis system with 1 billion data per day
2. Case combat: practice of troubleshooting OOM problems caused by too many service class loaders
3. Case actual combat: the practice of troubleshooting frequent OOM memory overflow in a data synchronization system
4. Online system JVM parameter optimization, GC problem location and troubleshooting, OOM analysis and solution
5. How to show your JVM actual combat experience in the interview

 

 

This set of [ JVM master actual combat list ], nearly a hundred episodes, from 0 to become a JVM technology master, friends who need the full version, can forward this article and follow the editor

You can start 100% of the full version of [ JVM master combat list ]

Speaking of JVM tuning, most people think of JVM parameter tuning. When we see a problem, we can say that we add a certain parameter or adjust the value of a certain parameter. It is a unique sense of accomplishment. Prompted me to keep learning the fun of JVM.

Growth does not happen overnight. Behind all excellence is the accumulation of a single day!