After "eating" this Java performance tuning actual combat, MySQL+JVM+Tomcat and other problems are eliminated with one click

A friend went to a factory for an interview two days ago. The opening went smoothly, but it didn't take long for him to be optimistic about it.

I thought to myself, it’s already July and a half, and soon the autumn recruitment army is coming. Are there many friends who are also not enough in JAVA performance tuning? So today I’m writing this article, I just want to share with you a tuning note of the Ali P8 architect hand-knocking 20W words, and especially for the three special treatments of MySQL, Tomcat, and JVM, let’s take a look at my hand-painted Corresponding mind maps and high-frequency real questions and answers related to interviews.

Let's take a look at the actual performance of Java performance tuning

Due to too much space, I will directly come to the general catalog Kangkang. From the following catalogue, you can roughly know what the details include...

From the catalog, you can know that the content is too much, I will not explain it in detail. At the beginning, I said that I want to share this tuning note of the 20W word by the Ali P8 architect with everyone, so I privately wrote me **["Tuning"]** You can share the download method for free, and there are more interviews for MySQL, Tomcat, JVM, etc. and my pure hand-painted mind maps.

Let's look at the detailed content inside

• Java programming performance tuning

Java programming performance tuning

• Multi-threaded performance tuning

Multi-threaded performance tuning

• JVM performance monitoring and tuning

JVM performance monitoring and tuning

• Design pattern tuning

Design pattern tuning

• MySQL performance tuning

MySQL performance tuning

• Practice field

Practice field

MySQL's hand-drawn mind map + interview

• MySQL hand-drawn mind map

The xmind software used for hand-painting this mind map will have a detailed analysis on each branch point. The original can not be uploaded here, so take a screenshot. The original can be shared with the editor, and I ** "tuning" **Yes, whether it is performance tuning or hand-drawn mind maps and interviews.

MySQL hand-drawn mind map

• MySQL Interview (Ali P8 level, test your own level)

1. Tell me about the internal execution process of MySQL executing a query statement?
2. MySQL prompts that "this column does not exist" is reported to which node?
3. What are the advantages and disadvantages of the MySQL query cache function?
4. How to turn off the query cache function of MySQL?
5. What are the commonly used engines for MySQL?
6. Can MySQL set the database engine for the table level? How to set it up?
7. What is the difference between the commonly used storage engines InnoDB and MyISAM?
8. What are the features of InnoDB?
9. There are three pieces of data in an auto-increment table. After deleting two pieces of data, restart the database and add another piece of data. What is the ID of this piece of data?
10. What situation in MySQL can cause auto-increment primary keys to be inconsistent?
11. Can auto-incrementing primary keys in InnoDB be persisted?
12. What are independent table spaces and shared table spaces? What is the difference between them?
13. How to set up an independent table space?
14. How to shrink the table space?
15. Talk about the execution process of rebuilding the table?
16. Where does the structure information of the table exist?
17. What is a covering index?
18. If the primary key of an InnoDB table is deleted, is there no primary key and no way to query back to the table?
19. After executing an update statement, I execute the hexdump command to directly view the contents of the ibd file. Why do I not see any changes in the data?
20. What is the difference between a memory table and a temporary table?
21. What problems can concurrent transactions bring?
22. What are dirty reading and phantom reading?
23. Why is there a phantom reading? What problems will phantom reading bring?
24. How to avoid phantom reading?
25. How to check the idle connections of MySQL?
26. What are the string types in MySQL?
27. What is the difference between VARCHAR and CHAR? What are the applicable scenarios?
28. Which data type should be used for MySQL storage amount? why?
29. What is the meaning of limit 3,2?
30. What is the difference between now() and current_date()?
31. Why doesn't InnoDB record the total number and return it directly when querying?
32. Can the number of rows in the show table status be used directly as the total number of rows in the table? why?
33. Which of the following SQL has the highest query performance?
34. What are the advantages and disadvantages of indexes?
35. What is wrong with the following SQL? How to optimize?
36. Why does MySQL officially recommend using an auto-incrementing primary key as the primary key of a table?
37. What are the advantages and disadvantages of auto-incrementing primary keys?
38. How many types of indexes are there? How to create each?
39. What is the difference between primary index and unique index?
40. Why is the query performance of primary key index higher than ordinary index in InnDB?
41. What is the return table query?
42. 10. How to query all indexes of a table?
43. How many index columns can MySQL create at most?
44. Which option will the following like query use the index? why?
45. How to make like %abc use index query?
46. What should be paid attention to in MySQL joint index?
47. What is the role of the joint index?
48. What is the leftmost matching principle? What are its effective principles?
49. When the column value is NULL, will the query use the index?
50. Will the following statement be indexed?
51. Can an index be created for the first 6 digits of the mobile phone number? How to create?
52. What is a prefix index?
53. Why use prefix index?
54. When is it appropriate to use prefix indexes?
55. What is a page?
56. What are the common storage algorithms for indexes?
57. Why does InnoDB use B+ trees instead of B trees, Hash, red-black trees, or binary trees?
58. Why does InnoDB use B+ trees to store indexes?
59. Which one is better for unique index or ordinary index?
60. What are the factors affecting the optimizer's choice of query index?
61. How does MySQL determine the number of index scan rows?
62. How does MySQL get the index cardinality? Is it accurate?
63. What is a lock? How many types of locks are provided in MySQL?
64. What are the common deadlock cases?
65. How to deal with deadlocks?
66. How to check deadlock?
67. How to avoid deadlock?
68. How does InnoDB treat deadlocks by default?
69. How to enable deadlock detection?
70. What is a global lock? What are its application scenarios?
71. What is a shared lock?
72. What is an exclusive lock?
73. What problems can be caused by using global locks?
74. How to deal with the situation that the entire database cannot be inserted during logical backup?
75. How to set the database as a global read-only lock?
76. Except FTWRL can set the database to be read-only, what other methods are there?
77. What is the difference between FTWRL and set global readonly=true?
78. How to implement table lock?
79. What is the difference between pessimistic lock and optimistic lock?
80. What are the advantages and disadvantages of optimistic locking?
81. How many lock algorithms does the InnoDB storage engine have?
82. What are the important log files for MySQL?
83. What is the difference between redo log and binlog?
84. What is crash-safe?
85. What are dirty pages and clean pages?
86. Under what circumstances will cause MySQL to flush dirty pages (flush) operation?
87. What could be the reason why MySQL flushes dirty pages very slowly?
88. How to control MySQL to refresh only the current dirty pages?
89. What problem does MySQL's WAL technology solve?
90. Why do I sometimes feel that MySQL gets stuck occasionally?
91. How are redo log and binlog related?
92. How does MySQL know that binlog is complete?
93. Can I just use binlog in MySQL instead of redo log?
94. Can I just redo log instead of binlog in MySQL?
95. Why is the binlog cache maintained by each thread, while the redo log buffer is shared globally?
96. During the execution of the transaction, it has not been submitted. If a crash occurs and the redo log is lost, will it cause inconsistency between the master and the backup?
97. What mechanism is used in MySQL to optimize the IO consumption of random read/write disks?
98. Is there a way to restore MySQL data to a specified time node in the past? How to recover?
99. MySQL commands and built-in functions
100. How to connect to MySQL database by command line?
101. About the command mysql -h 127.0.0.1 -uroot -P 3307 -p3307 What is wrong with the following statement?
102. How to create users? And authorize the user?
103. How to change MySQL password?
104. How to use SQL to create a database and set the encoding format of the database?
105. How to modify the encoding format of databases and tables?
106. How to create a table using SQL?
107. How to view table structure information in MySQL command line?
108. How to use SQL to view the table creation script of a known table?
109. How to update the table structure using SQL statements?
110. What are the deletion methods for MySQL? What's the difference?
111. How to open and close MySQL service?
112. How to query the version number of the current MySQL installation?
113. How to check the storage engine of a table?
114. How to view the statistics of the number of executions of the current database addition, deletion, modification, and query?
115. How to query the number of thread connections?
116. How to check the maximum number of MySQL connections? Can it be modified? How to modify?
117. What is the difference between CHAR_LENGTH and LENGTH?
118. What is the purpose of UNION and UNION ALL? What's the difference?
119. Which of the following statements about WHERE and HAVING are correct?
120. What are the MySQL performance indicators? How to get these indicators?
121. What is a slow query?
122. How to enable slow query log?
123. How to locate slow queries?
124. What are the optimization methods of MySQL?
125. What are the common MySQL read-write separation solutions?
126. Tell me about the function and execution process of Sharding-JDBC?
127. What is MySQL multi-instance? How to configure MySQL multi-instance?
128. How to ensure that there is no delay in the standby database?

There are 128 questions in total. Here are the answers. There are 64 pages of questions and answers...

Analysis of answers to MySQL Ali P8 interview

Java virtual machine-JVM hand-drawn mind map + interview

• JVM hand-drawn mind map

JVM hand-drawn mind map

• JVM interview

1. Java class loading process?
2. Describe the principle mechanism of JVM loading Class files?
3. Java memory allocation
4. What is GC? Why is GC?
5. Briefly describe the Java garbage collection mechanism
6. How to judge whether an object is alive? (Or how to determine the GC object)
7. The advantages and principles of garbage collection. And consider 2 recycling mechanisms
8. What is the basic principle of the garbage collector? Can the garbage collector reclaim memory immediately? Is there any way to proactively notify the virtual machine for garbage collection?
9. Will there be a memory leak in Java, please describe briefly
10. Deep copy and shallow copy
11. What will System.gc() and Runtime.gc() do?
12. When is the finalize() method called? What is the purpose of finalization?
13. If the object's reference is set to null, will the garbage collector immediately release the memory occupied by the object?
14. What is distributed garbage collection (DGC)? How does it work?
15. What is the difference between a serial collector and a throughput collector?
16. In Java, when can an object be garbage collected?
17. Briefly describe the Java memory allocation and recovery strategy and Minor GC and MajorGC
18. Will garbage collection occur in the permanent generation of the JVM?
19. What are the methods of garbage collection in Java?
20. What are class loaders and what are the class loaders?

JVM interview answer analysis

Tomcat tuning

• Tomcat tuning interview questions

1. How do you tune tomcat?
2. How to increase the number of tomcat connections?
3. How to prohibit listing files in tomcat?
4. How to increase the memory of tomcat?
5. How many ways to deploy Tomcat?
6. Tomcat optimization experience?
7. … …

Tomcat tuning interview question answer analysis

• Tomcat architecture analysis document

Final statement

The actual performance tuning of JAVA mentioned in the full text + MySQL interview-hand-drawn mind map + JVM hand-drawn mind map-interview + Tomcat interview-architecture analysis document , if you feel that you need to learn more about tuning to deal with autumn recruitment , then The editor can share all the originals with you for free . Just click here to get it.