Interview upgrade hit the blame-middle to high process

1.php memory allocation principle, the processing of reference or assignment, garbage collection mechanism, the operation principle of the array. array functions, String functions, sorting functions. PHP5, the principle of var_dump mechanism, simulate a bit.
2. Data Structure Btree Index implementation Method binary tree (relational design program is reasonable, know more design ideas more)
3.redis 5 Data structures using scenario Master-slave replication for process caching and database consistency solution implementation distributed lock AOF and RDB persistence strategy read/write Separation Architecture Sentinel architecture and data loss problem performance optimization ideas high availability and high scalability architecture Cache breakdown Batch Query optimizes the allocation of high-performance clustered Redis slots How to do if the Redis master node is down and there are no synchronized data?
4.mysql index implementation, optimizing lookup primary key index unique index federated Index single index full-text index (hash, btree difference)

Understand MySQL underlying b+tree mechanism, SQL execution Plan details, SQL statement optimization, and index optimization

MySQL master-slave copy and read/write separation practice

Mysql+keepalvad implementation of dual Master high availability scheme

MySQL High performance Solution sub-database sub-table

Preliminary knowledge Mycat of database middleware

Realization of MySQL database read-write separation based on Mycat

Implementation of database segmentation strategy based on Mycat

5.PHP7 Change
6.nginx Reverse proxy server and load Balancer Server configuration practice based on Nginx to implement access control, continuously restrict nginx static and dynamic separation practice nginx location, rewrite and other syntax configuration and principle analysis N Ginx how the algorithm for load balancing of HTTPS services is implemented

Practice of real-time escalation Kafka based on Nginx+lua completion of access traffic

Nginx's upstream currently supports 4 different ways of distribution
1), polling (default)
Each request is assigned to a different back-end server in chronological order, and can be automatically rejected if the backend server is down.
2), Weight
Specifies the polling probability, proportional to the weight and access ratios, for situations where the performance of the backend server is uneven.
2), Ip_hash
Each request is allocated according to the hash result of the access IP, so that each visitor has fixed access to a back-end server that resolves the session issue.
3), Fair (third party)
The response time of the back-end server is allocated to the request, and the response time is short of priority allocation.
4), Url_hash (third party)

Nginx built-in policy includes weighted polling and IP hash

Weighted polling algorithm is divided into the first deep search and the first wide search, then Nginx is the first deep search algorithm, will be the first to assign the request to a high-weight machine, until the machine's weight down to lower than other machines, only to start the request to the next high-weight machine;
How to solve the surprise group phenomenon?

Panic swarm is caused by multiple child processes listening to the same port at the same time;

Nginx Workaround: Only one worker child process can listen to the Web port at the same time, and the new connection event can only wake up the worker subprocess that is listening on the port.

Adopt lock, mutual exclusion amount realizes!!

7.memcache Multithreading Redis Single Thread differences

8.innodb MyISAM Difference

9.GIT: What is git and how it works, git commands best practise (avoid pit teaching), how git conflicts are caused, how to resolve, architect responsibilities git flow spec team git use procedures. There are no partitions. Work area staging Area remote Area

10. Design mode Factory mode simple interest Mode observer mode

11. Algorithm bubble dichotomy fast-discharging recursive closure time complexity spatial complexity data structure knowledge

12.http Status Code 403 501 502 301 302 http and HTTPS differences between TCP and UDP protocols

13. Network HTTP three handshake, four wave

What are the 14.web unsafe factors? Attack mode or principle? How to guard against each other? XSS, CSRF, SQL injection

15. Briefly php-fpm, how to determine how many PHP processes a machine should open? Process management tools.

Interview upgrade to blame-medium to high process