Preemptive multitasking using coroutines in PHP Swoole

PHP Swoole enables PHP developers to write high-performance, scalable, concurrent TCP, UDP, Unix socket, HTTP, WebSocket services in PHP programming language.

Compared with other async programming frameworks or software such as Nginx, Tornado, Node.js, Swoole has the built-in async, coroutines, multiple threads I/O modules.

Preemptive scheduling is the key to building a high performance, low latency, near the real-time system.

Compared with other programming languages or frameworks, PHP Swoole is one of the very few supports preemptive multitasking using coroutines.

This talk we like to introduce the coroutines in PHP Swoole and the implementation of a multitasking coroutines scheduler in PHP Swoole.

Transcript

1. Preemptive multitasking using coroutines in PHP Swoole Bruce Dou | @doubaokun bruce@transfon.com 6th Jun 2019
2. 1. Evolution of web server or services 2. The problems to solve for PHP 3. Coroutinesand preemptive schedulingfor PHP 4. Show case preemptivescheduling in PHP Swoole Agenda
3. About me • Software Architect & Head of Development • Founderat Transfon • Twitter:@doubaokun • Email:bruce@transfon.com • Linkedin:linkedin.com/in/brucedou • Github: github.com/doubaokun
4. Security Performance Regulation compliance Cost control About Transfon
5. Evolution of web server or services
7. https://unixism.net/2019/04/linux-applications-performance-introduction/
8. I/O bound vs CPU bound
9. Decoupling I/O and Computation
10. Async and non-blocking I/O
11. Why non-blocking I/O matters Multiple cores and fast CPU vs slow Network I/O
12. Linux I/O multiplexing, non-blocking • select() monitors the sockets’ status flag and return the status of all sockets, manually iterate through all the fds (C10K problem) • poll() similar to select() but allocate an array of pollfd, can handle more than 1024 sockets •epoll() monitors sockets’ status and trigger related events, and only return triggered events array.
13. Reactor pattern
14. PHP ?
15. The problems to solve for PHP • High concurrency,large numberof connections • Long-liveconnections,real-timeservices • Long-liveconnectionsto DB, Cache, RPC etc • Supportmoreprotocols • Server programming,not just scripts • Milliseconds scheduler • Async tasks of consuming3rd party services • Manage and reuse the statusin memory • Performance
17. 1.Receive the request 2.Load and compile PHP files and codes 3.Initialize the context objects and variables 4.Execute the functions 5.Send the response 6.Recycle the resources The life cycle of HTTP request in PHP-FPM
18. 1.Load and compile files and codes 2.Initialize the context objects and variables 3.Receive the request 4.Execute the functions 5.Send the response 6.Recycle the resources The life cycle of HTTP request in PHP Swoole
19. PHP Swoole https://www.swoole.co.uk/ https://github.com/swoole/swoole-src @php_swoole Coroutine-based concurrency library for PHP
20. Get started git clone git@github.com:doubaokun/phplondon201906.git docker build -f Dockerfile -t swoole-phplondon . docker run --rm -p 9501:9501 -v $(pwd):/app -w /app \ swoole-phplondon server.php
21. How it looks like
22. How fast
23. Open Source(Apache2 license) PHP Extension C/C++ / Boost.Context Callbackstyle & Coroutine Event-basednon-blockingI/O HTTP/HTTP2/Websocket/TCP/UDPetc Milliseconds task scheduler Process manager Preemptivescheduling PHP Swoole
24. The problems we like to solve further • Callback hell • Use Coroutinestyle (sync) concurrency • Automaticallycontextswitchbasedon I/O • Soft real-time • Long tail latency • One bad guy stopthe world
25. Callback hell
26. Callback hell Swoole 2.x.x
27. I/O based automatically scheduling in PHP Swoole
28. I/O based automatically scheduling
29. Coroutines in PHP Swoole
30. Coroutines in PHP Swoole
31. Problem with CPU heavy business logics
32. Preemptive scheduling
33. PHP Swoole Server
34. HTTP server with PHP Swoole
36. HTTP server structure
37. Preemptive scheduling in PHP Swoole Server
38. Scheduling thread ZendVM:EG(vm_interrupt)= 1 Zend_interrupt_function Yield current coroutineif it runs longer than 5ms How preemptive scheduling works
39. Preemptive scheduling in PHP Swoole Server
40. HTTP server structure single process
41. Preemptive scheduling in PHP Swoole Server time curl -I http://127.0.0.1:9501/\?p\=1 (CPU heavy logics) time curl -I http://127.0.0.1:9501/\?p\=0 (light weight logics) docker run --rm -p 9501:9501 -v $(pwd):/app -w /app \ swoole-phplondon server_preemptive.php time curl -I http://127.0.0.1:9501/\?p\=1 & sleep 1 && \ time curl -I http://127.0.0.1:9501/\?p\=0 & wait
42. Preemptive scheduling in PHP Swoole Server ini_set("swoole.enable_preemptive_scheduler", "0");
43. Preemptive scheduling in PHP Swoole Server ini_set("swoole.enable_preemptive_scheduler", "1");
44. Real world meaningof preemptive scheduling
45. Real-world meaning of preemptive scheduling
46. https://github.com/doubaokun/phplondon201906 https://www.swoole.co.uk/ https://github.com/swoole/swoole-src https://swoole.slack.com https://twitter.com/php_swoole Thank you