Backend Development
Python Tutorial
Installation and usage tips of Python's network programming library Gevent
Installation and usage tips of Python's network programming library Gevent
Installation (taking CentOS as an example)
gevent depends on libevent and greenlet:
1. Install libevent
Direct yum install libevent
Then configure the python installation
2. Install easy_install
(1)
wget -q http://peak.telecommunity.com/dist/ez_setup.py
(2) Use
python ez_setup.py
(3) Use easy_install to check whether the command is available. If not, you can add the path to PATH
3. Install greenlet
(1)
yum install python-devel
(2)
easy_install greenlet
4. Install gevent
pip install cython -e git://github.com/surfly/gevent.git@1.0rc2#egg=gevent
Tips
The Gevent library has high performance, but I have always been troubled by the fact that threads cannot seize multi-core resources due to Python's GIL model.
The multi-core mode of starting multiple python processes requires adding front-end load balancing, such as lvs, which is a bit troublesome.
The multiprocessing module and os.fork will cause the two processes to repeatedly register accept events in the event core, resulting in duplicate file handle exceptions.
As for the mode of one process monitoring and multiple process processing, the resources of the monitoring process are not easy to allocate - should one core be allocated independently or not? If allocated separately, a core will be wasted when the number of connections is small. If not allocated, the CPU will frequently switch processes when the number of connections is large.
I just discovered yesterday that gevent can easily distribute its network model to multiple processes for parallel processing.
The secret is gevent.fork().
I used to take it for granted that gevent.fork is just a wrapper for greenlet.spawn, but it turns out that's not the case. gevent.fork can replace os.fork, which not only starts a new process, but also communicates their underlying event processing for parallel processing.
import gevent
from gevent.server import StreamServer
def eat_cpu():
for i in xrange(10000): pass
def cb(socket, address):
eat_cpu()
socket.recv(1024)
socket.sendall('HTTP/1.1 200 OK\n\nHello World!!')
socket.close()
server = StreamServer(('',80), cb, backlog=100000)
server.pre_start()
gevent.fork()
server.start_accepting()
server._stopped_event.wait()
After adding monkey.patch_os, os.fork can be replaced by gevent.fork, so that the multiprocessing module can be used as usual and achieve the effect of parallel processing.
from gevent import monkey; monkey.patch_os()
from gevent.server import StreamServer
from multiprocessing import Process
def eat_cpu():
for i in xrange(10000): pass
def cb(socket, address):
eat_cpu()
socket.recv(1024)
socket.sendall('HTTP/1.1 200 OK\n\nHello World!!')
socket.close()
server = StreamServer(('',80), cb, backlog=100000)
server.pre_start()
def serve_forever():
server.start_accepting()
server._stopped_event.wait()
process_count = 4
for i in range(process_count - 1):
Process(target=serve_forever, args=tuple()).start()
serve_forever()
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Google AI announces Gemini 1.5 Pro and Gemma 2 for developers
Jul 01, 2024 am 07:22 AM
Google AI has started to provide developers with access to extended context windows and cost-saving features, starting with the Gemini 1.5 Pro large language model (LLM). Previously available through a waitlist, the full 2 million token context windo
How to download deepseek Xiaomi
Feb 19, 2025 pm 05:27 PM
How to download DeepSeek Xiaomi? Search for "DeepSeek" in the Xiaomi App Store. If it is not found, continue to step 2. Identify your needs (search files, data analysis), and find the corresponding tools (such as file managers, data analysis software) that include DeepSeek functions.
How do you ask him deepseek
Feb 19, 2025 pm 04:42 PM
The key to using DeepSeek effectively is to ask questions clearly: express the questions directly and specifically. Provide specific details and background information. For complex inquiries, multiple angles and refute opinions are included. Focus on specific aspects, such as performance bottlenecks in code. Keep a critical thinking about the answers you get and make judgments based on your expertise.
How to search deepseek
Feb 19, 2025 pm 05:18 PM
Just use the search function that comes with DeepSeek. Its powerful semantic analysis algorithm can accurately understand the search intention and provide relevant information. However, for searches that are unpopular, latest information or problems that need to be considered, it is necessary to adjust keywords or use more specific descriptions, combine them with other real-time information sources, and understand that DeepSeek is just a tool that requires active, clear and refined search strategies.
How to program deepseek
Feb 19, 2025 pm 05:36 PM
DeepSeek is not a programming language, but a deep search concept. Implementing DeepSeek requires selection based on existing languages. For different application scenarios, it is necessary to choose the appropriate language and algorithms, and combine machine learning technology. Code quality, maintainability, and testing are crucial. Only by choosing the right programming language, algorithms and tools according to your needs and writing high-quality code can DeepSeek be successfully implemented.
How to use deepseek to settle accounts
Feb 19, 2025 pm 04:36 PM
Question: Is DeepSeek available for accounting? Answer: No, it is a data mining and analysis tool that can be used to analyze financial data, but it does not have the accounting record and report generation functions of accounting software. Using DeepSeek to analyze financial data requires writing code to process data with knowledge of data structures, algorithms, and DeepSeek APIs to consider potential problems (e.g. programming knowledge, learning curves, data quality)
The Key to Coding: Unlocking the Power of Python for Beginners
Oct 11, 2024 pm 12:17 PM
Python is an ideal programming introduction language for beginners through its ease of learning and powerful features. Its basics include: Variables: used to store data (numbers, strings, lists, etc.). Data type: Defines the type of data in the variable (integer, floating point, etc.). Operators: used for mathematical operations and comparisons. Control flow: Control the flow of code execution (conditional statements, loops).
Problem-Solving with Python: Unlock Powerful Solutions as a Beginner Coder
Oct 11, 2024 pm 08:58 PM
Pythonempowersbeginnersinproblem-solving.Itsuser-friendlysyntax,extensivelibrary,andfeaturessuchasvariables,conditionalstatements,andloopsenableefficientcodedevelopment.Frommanagingdatatocontrollingprogramflowandperformingrepetitivetasks,Pythonprovid
