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 unKonf 2017 in Mannheim

Transcript

1. October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF Async PHP Requests & Reactive Responses with PHP-FPM // unKonf
3. + async
4. USE CASE PDF CREATION SERVICE
5. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USE CASE (PDF CREATION) 5 WEB-SERVICE
6. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USE CASE (PDF CREATION) 6 WEB-SERVICE SEQUENTIAL PROCESSING IS OK(-ish)
7. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USE CASE (PDF CREATION) 7 WEB-SERVICE BUT: WHAT IF…
8. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USE CASE (PDF CREATION) 8 PARALLELISM TO THE RESCUE
9. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE TRIED… 9 <?php 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
10. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WORKS, BUT… 10 ๏ 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)
11. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE TRIED… 11 <?php $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 <?php $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 );
12. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WORKS, BUT… 12 ๏ 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)
13. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE TRIED VERY HARD… 13 <?php $pdo->query( "INSERT INTO queue (id, script, data) VALUES ('123', '/create-pdf.php', '{json}')" ); #/>$ crontab -e */1 * * * * php "/path/to/queue-processor.php" +
14. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WORKS, BUT… 14 ๏ 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
15. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE TRIED TO BE CLEVER… 15 <?php function runInBackground() { include '/create-pdf.php'; } register_shutdown_function( 'runInBackground' ); header( 'Location: /show/user/a/page.php', true, 301 ); flush();
16. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WORKS, BUT… 16 ๏ WEBSERVER INVOLVED ๏ RESPONSE ENDS UP IN NIRVANA ๏ MEMORY LEAKS FOR THE WIN! ๏ PRETTY HARD ERROR HANDLING ๏ NO EXECUTION TIME LIMIT ๏ WTF? - DON’T TRY TO BE CLEVER!
17. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE COULD USE… 17 pthreads
18. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE COULD USE… 18 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
19. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE COULD USE… 19 pcntl
20. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE COULD USE… 20 pcntl ๏ NEEDS CUSTOM PHP BUILD ๏ NOT WORKING ON WINDOWS ๏ BASIC KNOWLEDGE ABOUT UNIX PROCESSES NEEDED ๏ PROCESS MANAGEMENT IS UP TO YOU
21. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WE COULD USE… 21 ๏ NEEDS ANOTHER PIECE OF INFRASTRUCTURE + PHP EXTENSION ๏ FEATURE RICH, BUT OVERLOADED FOR SIMPLE ASYNC TASKS ๏ A LOT OF SETUP FOR LOCAL DEVELOPMENT
22. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WHAT DO WE WANT? 22 ๏ 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
23. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf WHAT IF I TOLD YOU… 23 ๏THERE IS A BULLET-PROOF PROCESS MANAGER SHIPPED WITH PHP ๏…AND YOU’RE PROBABLY USING IT ALREADY.
24. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf 24 PHP-FPM (PHP FastCGI Process Manager)
25. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf 25 WEBSERVER
 (NGINX, APACHE) PHP-FPM HOW IT USUALLY WORKS POOL (WWW) 1..N PROCESSES PHP WEB CONTEXT
26. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf 26 WEBSERVER
 (NGINX, APACHE) PHP-FPM HOW IT USUALLY WORKS POOL (WWW) 1..N PROCESSES POOL (BACKGROUND)
 1..N PROCESSES QUEUE PHP WEB CONTEXT
27. hollodotme/fast-cgi-client
28. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf CONNECT TO UNIX DOMAIN SOCKET 28 <?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 'unix:///var/run/php/php7.1-fpm.sock', # Connect timeout in milliseconds (default: 5000) 5000, # Read/write timeout in milliseconds (default: 5000) 5000 ); $client = new Client( $connection );
29. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf PHP-FPM POOL CONFIG UNIX DOMAIN SOCKET 29 ; 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
30. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf CONNECT TO NETWORK SOCKET 30 <?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 9000, # Connect timeout in milliseconds (default: 5000) 5000, # Read/write timeout in milliseconds (default: 5000) 5000 ); $client = new Client( $connection );
31. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf PHP-FPM POOL CONFIG NETWORK SOCKET 31 ; 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
32. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf SEND A SYNCHRONOUS REQUEST 32 <?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();
33. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf RESPONSE INTERFACE 33 <?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; }
34. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf ASYNC FIRE & FORGET 34 <?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}";
35. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf ASYNC REQUEST + WAIT FOR RESPONSE 35 <?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();
36. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USING RESPONSE CALLBACKS 36 <?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 );
37. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USING PASS THROUG CALLBACKS 37 <?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 );
38. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf USING RESPONSE CALLBACKS 38 <?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; } }
39. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - ORDERED RESPONSES 39 <?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"; }
40. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - ORDERED RESPONSES 40 # PRINTS Response #1 Response #2 Response #3 ๏ NO MATTER HOW LONG EACH WORKER TOOK TO RESPOND
41. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - REACTIVE RESPONSES 41 <?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 '.'; }
42. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - REACTIVE RESPONSES 42 <?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 '.'; }
43. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - REACTIVE RESPONSES 43 # PRINTS .....Response #2 .......Response #3 ..........Response #1 ๏ ORDERED BY RESPONSE TIME
44. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf MULTIPLE REQUESTS - REACTIVE CALLBACKS 44 <?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 ); } }
45. QUESTIONS?
46. THANK YOU! github.com/hollodotme @hollodotme / @F9T3ch fortuneglobe.com phpug-dresden.org @phpugdd HOLGER WOLTERSDORF icehawk.github.io speakerdeck.com/hollodotme Slides available at:
47. ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • October 28th 2017 • unKonf • Mannheim HOLGER WOLTERSDORF // unKonf LINKS / REFERENCES 47 ๏ 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