Async PHP Requests & Reactive Responses with PHP-FPM

There are many approaches to execute PHP sub-tasks asynchronously or to parallelise PHP execution. While some solutions require extra extensions, individual PHP builds or a lot of process control management, this talk will show you how to configure and use the built-in PHP FastCGI Process Manager (php-fpm) to execute requests asynchronously in an isolated, tunable process pool and eventually handle their responses in a reactive way.

Talk at FOSDEM 2019 in Brussels

Transcript

1. FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF Async PHP Requests & Reactive Responses with PHP-FPM
2. HOLGER WOLTERSDORF CIO • FATHER • HUSBAND • PHP DEV WITH ♥ github.com/hollodotme @hollodotme
4. + async
5. USE CASE A PDF CREATION SERVICE
6. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USE CASE (PDF CREATION) 6 WEB-SERVICE
7. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USE CASE (PDF CREATION) 7 WEB-SERVICE SEQUENTIAL PROCESSING IS OK(-ish)
8. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USE CASE (PDF CREATION) 8 WEB-SERVICE BUT WHAT IF…
9. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USE CASE (PDF CREATION) 9 PARALLELISM TO THE RESCUE
10. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE TRIED… 10 exec('php "/create-pdf.php" > /dev/null 2>&1 &'); # OR shell_exec('php "/create-pdf.php" > /dev/null 2>&1 &'); # OR proc_open('php "/create-pdf.php"', $descriptorSpec ); PHP 4 - 2001
11. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WORKS, BUT… 11 ๏PHP SCRIPT IS CALLED IN CLI MODE (DIFFERENT ENVIRONMENT) ๏COMMAND GETS QUIET MESSY WHEN A LOT OF DATA SHOULD BE PASSED ๏DATA HANDLING IN CALLED SCRIPT BASED ON $ARGV ARRAY ๏RESPONSE ENDS UP IN NIRVANA ๏DEBUGGING IS A NIGHTMARE (ESPECIALLY IN PRODUCTION)
12. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE TRIED… 12 $scriptUrl = 'http:#//##www.yoursite.com/create-pdf.php'; $ch = curl_init(); curl_setopt( $ch, CURLOPT_URL, $scriptUrl ); curl_setopt( $ch, CURLOPT_FRESH_CONNECT, true ); curl_setopt( $ch, CURLOPT_TIMEOUT_MS, 1 ); curl_exec( $ch ); curl_close( $ch ); PHP 5.2.3 - 2009
13. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WORKS, BUT… 13 ๏WEBSERVER ALWAYS INVOLVED (= OVERHEAD + ERROR SOURCE) ๏MAYBE A LOAD BALANCER INVOLVED, TOO ๏AT LEAST 2 ENVIRONMENTS TO MAINTAIN ๏CURL EXTENSION NEEDED ๏RESPONSE ENDS UP IN NIRVANA ๏CALLED SCRIPT MUST BE EXPOSED (UNDER DOMAIN’S DOCUMENT ROOT)
14. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE TRIED VERY HARD… 14 $pdo#->query( "INSERT INTO queue (id, script, data) VALUES ('123', '/create-pdf.php', '{json}')" ); $ crontab -e #*/1 * * * * php "/path/to/queue-processor.php" +
15. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WORKS, BUT… 15 ๏ NO ON-DEMAND EXECUTION ๏ NEEDS A LOT OF LOCKING AND LOGGING ๏ RAISE CONDITIONS FOR THE WIN! ๏ ERRORS CAN PILE UP UNTIL SERVER IS DEAD ๏ HEAVY DATABASE LOAD FOR TECHNICALLY ELUSIVE DATA (HINT: BAD IDEA) ๏ MAINTENANCE OUTSIDE PHP PROJECT NEEDED (CRONTAB) ๏ HARD TO TEST
16. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE TRIED TO BE CLEVER… 16 function runInBackground() { include '/create-pdf.php'; } register_shutdown_function( 'runInBackground' ); header( 'Location: /show/user/a/page', true, 301 ); flush();
17. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WORKS, BUT… 17 ๏WEBSERVER INVOLVED ๏RESPONSE ENDS UP IN NIRVANA ๏MEMORY LEAKS FOR THE WIN! ๏PRETTY HARD ERROR HANDLING ๏NO EXECUTION TIME LIMIT
18. DON’T TRY TO BE CLEVER!
19. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE COULD USE… 19 pthreads
20. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE COULD USE… 20 pthreads ๏NEEDS CUSTOM PHP BUILD ๏NOT ALL EXTENSIONS ARE THREAD-SAFE ๏NOT WORKING IN WEB ENVIRONMENT ๏BASIC KNOWLEDGE ABOUT MULTI THREADING NEEDED ๏FEATURE AND CONFIG OVERHEAD FOR SIMPLE ASYNC TASKS ๏PROCESS / THREAD MANAGEMENT IS UP TO YOU
21. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE COULD USE… 21 pcntl
22. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE COULD USE… 22 pcntl ๏NEEDS CUSTOM PHP BUILD ๏NOT WORKING ON WINDOWS ๏BASIC KNOWLEDGE ABOUT UNIX PROCESSES NEEDED ๏PROCESS MANAGEMENT IS UP TO YOU
23. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WE COULD USE… 23 ๏NEEDS ANOTHER PIECE OF INFRASTRUCTURE + PHP EXTENSION ๏FEATURE RICH, BUT OVERLOADED FOR SIMPLE ASYNC TASKS ๏A LOT OF SETUP FOR LOCAL DEVELOPMENT
24. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WHAT DO WE WANT? 24 ๏ MAKE ASYNC CALLS TO PHP ๏ EVENTUALLY GET THE RESPONSES ๏ NO ADDITIONAL INFRASTRUCTURE ๏ NO ADDITIONAL EXTENSIONS ๏ WEB-REQUEST-LIKE DATA HANDLING (BECAUSE WE’RE USED TO IT) ๏ TAKE ADVANTAGE OF OPCACHE ๏ BACKGROUND WORKERS NOT EXPOSED TO "PUBLIC" ๏ TUNEABLE PROCESS MANAGEMENT
25. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF WHAT IF I TOLD YOU… 25 THERE IS A BULLET-PROOF PROCESS MANAGER SHIPPED WITH PHP … AND YOU’RE PROBABLY USING IT ALREADY.
26. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF 26 PHP-FPM (PHP FastCGI Process Manager)
27. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF 27 WEBSERVER
 (NGINX, APACHE) PHP-FPM HOW IT USUALLY WORKS POOL (WWW) 1..N PROCESSES PHP WEB CONTEXT
28. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF HOW IT USUALLY WORKS 28 PID TIME COMMAND 1365 00:00:01 php-fpm: master process (/etc/php/7.1/fpm/php-fpm.conf) 1719 00:00:00 php-fpm: pool ##www 1720 00:00:00 php-fpm: pool ##www 4529 00:00:01 php-fpm: pool ##www LOOKS FAMILIAR?
29. hollodotme/fast-cgi-client
30. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF 30 WEBSERVER
 (NGINX, APACHE) PHP-FPM HOW IT WORKS POOL (WWW) 1..N PROCESSES POOL (BACKGROUND)
 0..N PROCESSES PHP WEB CONTEXT
31. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF 31 WEBSERVER
 (NGINX, APACHE) PHP-FPM HOW IT WORKS POOL (WWW) 1..N PROCESSES POOL (BACKGROUND)
 0..N PROCESSES QUEUE PHP WEB CONTEXT
32. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF PHP-FPM POOL CONFIG UNIX DOMAIN SOCKET 32 ; Pool name [background] ; Process ownership user = ##www-data group = ##www-data ; Socket path listen = /var/run/php/php7.1-fpm-background.sock ; Socket ownership listen.owner = ##www-data listen.group = ##www-data ; Process management pm = ondemand ; Maximum of children that can be alive at the same time pm.max_children = 100 ; Number of seconds after which an idle children will be killed pm.process_idle_timeout = 10s
33. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF CONNECT TO UNIX DOMAIN SOCKET 33 <?php declare(strict_types=1); namespace YourVendor\YourProject; use hollodotme\FastCGI\Client; use hollodotme\FastCGI\SocketConnections\UnixDomainSocket; $connection = new UnixDomainSocket( # Socket path to php-fpm '/var/run/php/php7.1-fpm-background.sock', # Connect timeout in milliseconds (default: 5000) 5000, # Read/write timeout in milliseconds (default: 5000) 5000 ); $client = new Client( $connection );
34. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF CONNECT TO NETWORK SOCKET 34 <?php declare(strict_types=1); namespace YourVendor\YourProject; use hollodotme\FastCGI\Client; use hollodotme\FastCGI\SocketConnections\NetworkSocket; $connection = new NetworkSocket( # Hostname or IP '127.0.0.1', # Port 9001, # Connect timeout in milliseconds (default: 5000) 5000, # Read/write timeout in milliseconds (default: 5000) 5000 ); $client = new Client( $connection );
35. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF PHP-FPM POOL CONFIG NETWORK SOCKET 35 ; Pool name [background] ; Process ownership user = ##www-data group = ##www-data ; Socket IP and Port listen = 127.0.0.1:9001 ; Socket ownership listen.owner = ##www-data listen.group = ##www-data ; Process management pm = ondemand ; Maximum of children that can be alive at the same time pm.max_children = 100 ; Number of seconds after which an idle children will be killed pm.process_idle_timeout = 10s
36. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF SEND A SYNCHRONOUS REQUEST 36 <?php declare(strict_types=1); # Content-type: ’application/x-##www-form-urlencoded’ (default) $content = http_build_query( ['key' #=> 'value'] ); # Simulate HTTP Verbs: GET, POST, PUT, PATCH, DELETE $request = new PostRequest( '/create-pdf.php', $content ); $response = $client#->sendRequest( $request ); echo $response#->getBody();
37. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF RESPONSE INTERFACE 37 <?php declare(strict_types=1); namespace hollodotme\FastCGI\Interfaces; interface ProvidesResponseData { public function getRequestId() : int; public function getHeaders() : array; public function getHeader( string $headerKey ) : string; public function getBody() : string; public function getRawResponse() : string; public function getDuration() : float; }
38. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF ASYNC REQUEST (FIRE & FORGET) 38 <?php declare(strict_types=1); $client = new Client( new NetworkSocket( '127.0.0.1', 9000 ) ); $content = http_build_query( ['key' #=> 'value'] ); $request = new PostRequest( '/create-pdf.php', $content ); $requestId = $client#->sendAsyncRequest( $request ); echo "Request sent, got ID: {$requestId}";
39. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF ASYNC REQUEST + WAIT FOR RESPONSE 39 <?php declare(strict_types=1); # ##... $requestId = $client#->sendAsyncRequest( $request ); echo "Request sent, got ID: {$requestId}"; # Do something in the meanwhile here ##... $response = $client#->readResponse( $requestId ); # Blocking call until response is received or read timed out echo $response#->getBody();
40. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USING RESPONSE CALLBACKS 40 <?php declare(strict_types=1); # Response callbacks expect a ProvidesResponseData instance # ##...variadic function $request#->addResponseCallbacks( function( ProvidesResponseData $response ) { echo $response#->getBody(); } ); # Failure callbacks expect a \Throwable instance # ##...variadic function $request#->addFailureCallbacks( function ( \Throwable $throwable ) { echo $throwable#->getMessage(); } ); $requestId = $client#->sendAsyncRequest( $request );
41. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USING PASS THROUG CALLBACKS 41 <?php declare(strict_types=1); # Pass through callbacks expect a string (output buffer) # ##...variadic function $request#->addPassThroughCallbacks( function( string $buffer ) { echo $buffer; } ); $requestId = $client#->sendAsyncRequest( $request );
42. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF USING RESPONSE CALLBACKS 42 <?php declare(strict_types=1); # ##... $client#->waitForResponse( $requestId ); # Inner loop # ##... is the same as while(true) # Outer loop { if ( $client#->hasResponse( $requestId ) ) { $client#->handleResponse( $requestId ); break; } }
43. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - ORDERED RESPONSES 43 <?php declare(strict_types=1); $requestIds = []; $requestIds[] = $client#->sendAsyncRequest( $request1 ); $requestIds[] = $client#->sendAsyncRequest( $request2 ); $requestIds[] = $client#->sendAsyncRequest( $request3 ); echo 'Sent requests: ' . implode( ', ', $requestIds ) . "\n"; # Do something else here in the meanwhile ##... # Blocking call until all responses are received or read timed out foreach ($client#->readResponses(5000, ##...$requestIds) as $response) { echo $response#->getBody() . "\n"; }
44. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - ORDERED RESPONSES 44 # PRINTS Response #1 Response #2 Response #3 ๏ NO MATTER HOW LONG EACH WORKER TOOK TO RESPOND
45. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE RESPONSES 45 <?php declare(strict_types=1); $requestIds = []; $requestIds[] = $client#->sendAsyncRequest( $request1 ); $requestIds[] = $client#->sendAsyncRequest( $request2 ); $requestIds[] = $client#->sendAsyncRequest( $request3 ); echo 'Sent requests: ' . implode( ', ', $requestIds ) . "\n"; # Do something else here in the meanwhile ##... while ( $client#->hasUnhandledResponses() ) { # read all ready responses foreach ( $client#->readReadyResponses() as $response ) { echo $response#->getBody() . "\n"; }
 echo '.'; }
46. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE RESPONSES 46 <?php declare(strict_types=1); # ##... is the same as while ( $client#->hasUnhandledResponses() ) { $readyRequestIds = $client#->getRequestIdsHavingResponse(); # read all ready responses foreach ( $readyRequestIds as $requestId ) { $response = $client#->readResponse( $requestId ); echo $response#->getBody() . "\n"; }
 echo '.'; }
47. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE RESPONSES 47 # PRINTS .....Response #2 .......Response #3 ..........Response #1 ๏ ORDERED BY RESPONSE TIME
48. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE CALLBACKS 48 <?php declare(strict_types=1); $client#->waitForResponses(); # Inner loop # ##... is the same as while ( $client#->hasUnhandledResponses() ) # Outer loop { $client#->handleReadyResponses(); } # ##... is the same as while ( $client#->hasUnhandledResponses() ) # Outer loop { $readyRequestIds = $client#->getRequestIdsHavingResponse(); foreach ( $readyRequestIds as $requestId ) { $client#->handleResponse( $requestId ); } }
49. DEMO!
50. QUESTIONS?
51. THANK YOU! github.com/hollodotme @hollodotme / @F9T3ch fortuneglobe.com phpug-dresden.org @phpugdd HOLGER WOLTERSDORF icehawk.github.io speakerdeck.com/hollodotme Slides available at:
52. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • FEBRUARY 2nd 2019 • FOSDEM BRUSSELS HOLGER WOLTERSDORF LINKS / REFERENCES 52 ๏ PHP USERGROUP DRESDEN e.V. http://phpug-dresden.org ๏ Asynchronous cURL Requests: http://www.paul-norman.co.uk/2009/06/asynchronous-curl-requests/ ๏ Arne Blankerts’ talk about nodejs + PHP: https://thephp.cc/dates/2016/02/confoo/just-married-node-js-and-php ๏ Original PHP FastCGI Client by Pierrick Charron: https://github.com/adoy/PHP-FastCGI-Client/ ๏ PHP FastCGI Client: https://github.com/hollodotme/fast-cgi-client ๏ PHP FastCGI Client Demo: https://github.com/hollodotme/fast-cgi-client-demo ๏ FastCGI Specification: http://www.mit.edu/~yandros/doc/specs/fcgi-spec.html ๏ Experimental use-case with rabbitMQ: https://hollo.me/php/experimental-async-php-volume-2.html