Self introduction
basis
HashMap
- Comparison of different JDK versions
- Why is it optimized in JDK1.8 and what are the problems with JDK1.7
- Expansion mechanism
- How to ensure thread safety
- The reason for choosing ConcurrentHashMap, why not choose HashTable, Synchronized, Lock, Collection.Synchronized
- Synchronized lock upgrade process
Spring
Transaction isolation level
- What
- Compare with data isolation level
AOP
- What are the implementation methods
- What are the practical applications in the project
reflection
- Use scenario: dynamic acquisition
- Performance issues: (reflection is an interpretation operation)
Nginx
- How to do load balancing: consistent hash, weighted hash, polling
- What are the commonly used load balancing algorithms
The internet
TCP three-way handshake
- Three-way handshake process
- Why not twice or four times
MySQL
Tuning
- Multiple index matching
- If the covering index and storage medium are mechanical hard drives, turn on MRR
- Common index: changeBuffer
- Index is not effective: SQL statement troubleshooting, index information is inaccurate (using AnalyzeTable)
- Is the index analyzed by Explain necessarily optimal?
- Index efficiency is not high, how to remedy: force index; covering index + leftmost principle
Hot data mass update solution
- Use cache
- How to solve the problem of full cache bandwidth? Can consider local cache
New Features of Java 8
- What are the new features
- Which ones have been used
- What optimizations have been made
project
Project responsibility performance
Modular
- Module split
- Calling between modules
- RPC principle
- RPC framework
- Timeout processing
- Cluster processing
- Message middleware
Troubleshooting
- The external traffic is normal, the log of this module increases sharply, the thread pool is full, how to troubleshoot
other
How to learn
Learning gains
The relationship between business and technology
- Technology drives business and business generates value
What do you want to ask the interviewer
Question source: A programmer interviewed a Java intern and showed a textbook answer. Will he come if he has two major offers?