web server
1 HTTP protocol
http: hypertext transfer protocol, based on the tcp way, will be more secure and safer. Agreement that specifies how to request the server, the server returns information how. As shown in FIG red marker block:
Open your browser electric provider advertising works:
We open a browser to access an electronic business platform Baidu and other goods or access the server at the time the request will get to the Cookie value, you get access to the history and resolution. When the next time you open the page, the ad will be recommended as the load from local history. That Cookie tracking website by users.
2 TCP three-way handshake fourth wave
Three-way handshake is essentially a four-way handshake, C syn incoming request data request link S, S server response data ack; S C client server again request to establish a link, C response to the S server. Since the intermediate and the S reply request may merge together, resulting in 3-way handshake. Essentially to establish the connection.
Four waving time, mainly closed when there may be a communication delay or end communication. It can not be combined. Essentially closes the connection.
- Long connected to the short connection
3 TCP-IP protocol
- Process browser to access the server
4 Python knowledge
- GIL Global Interpreter Lock
python sparked off in multi-process concurrency, multithreading can not introduce concurrency, GIL
- Deep copy
- Shallow copy
- Privatization
