May 31st 2017 • Péhápkaři • Prague HOLGER WOLTERSDORF Async PHP Requests & Reactive Responses with PHP-FPM 

HOLGER WOLTERSDORF CIO • FATHER • HUSBAND • PHP DEV WITH ♥ github.com/hollodotme @hollodotme 

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SEPTEMBER 22nd ARNE BLANKERTS thePHPcc SEBASTIAN HEUER kartenmacherei JAN BURKL ZEND MARCO PIVETTA Ocramius STEPHAN HOCHDÖRFER bitExpert ALEXANDER MIERTSCH prooph software CHRISTIAN LÜCK reactPHP 

PHP & ASYNC 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE TRIED… 6 /dev/null 2>&1 &', $output, $return_var ); # OR shell_exec('php "/path/to/script.php" > /dev/null 2>&1 &') PHP 4 - 2001 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WORKS, BUT… 7 ๏ 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 NIRWANA ๏ DEBUGGING IS A NIGHTMARE (ESPECIALLY IN PRODUCTION) 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE TRIED… 8

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WORKS, BUT… 9 ๏ 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 NIRWANA ๏ CALLED SCRIPT MUST BE EXPOSED (UNDER DOMAIN’S DOCUMENT ROOT) 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE TRIED VERY HARD… 10 query( "INSERT INTO queue (id, script, data) VALUES ('123', '/path/to/script.php', '{json}')" ); #/>$ crontab -e */1 * * * * php "/path/to/queue-processor.php" + 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WORKS, BUT… 11 ๏ 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 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE TRIED TO BE CLEVER… 12

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WORKS, BUT… 13 ๏ WEBSERVER INVOLVED ๏ RESPONSE ENDS UP IN NIRWANA ๏ MEMORY LEAKS FOR THE WIN! ๏ PRETTY HARD ERROR HANDLING ๏ NO EXECUTION TIME LIMIT ๏ WTF? - DON’T TRY TO BE CLEVER 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE COULD USE… 14 pthreads ๏ NEEDS CUSTOM PHP BUILD ๏ NOT ALL EXTENSIONS ARE THREAD-SAFE ๏ BASIC KNOWLEDGE ABOUT MULTI THREADING NEEDED ๏ FEATURE AND CONFIG OVERHEAD FOR SIMPLE ASYN TASKS ๏ PROCESS / THREAD MANAGEMENT IS UP TO YOU 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE COULD USE… 15 pcntl ๏ NEEDS CUSTOM PHP BUILD ๏ NOT WORKING ON WINDOWS ๏ BASIC KNOWLEDGE ABOUT UNIX PROCESSES NEEDED ๏ PROCESS MANAGEMENT IS UP TO YOU 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WE COULD USE… 16 ๏ NEEDS ANOTHER PIECE OF INFRASTRUCTURE + PHP EXTENSION ๏ FEATURE RICH, BUT OVERLOADED FOR SIMPLE ASYNC TASKS ๏ A LOT OF SETUP FOR LOCAL DEVELOPMENT 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WHAT DO WE WANT? 17 ๏ MAKE ASYNC CALLS TO PHP ๏ EVENTUALLY GET THE RESPONSE ๏ NO ADDITIONAL INFRASTRUCTURE ๏ NO ADDITIONAL EXTENSIONS ๏ WEB-REQUEST LIKE DATA HANDLING (BECAUSE WE’RE USED TO IT) ๏ BACKGROUND WORKERS NOT EXPOSED TO "PUBLIC" ๏ TUNEABLE PROCESS MANAGEMENT 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF THE IDEA… 18 TALK BY ARNE BLANKERTS AT CONFOO / IPC16 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WHAT I FOUND… 19 ๏ SEEMED OUTDATED AND UNMAINTAINED ๏ BUT DID A GOOD PART OF THE JOB PIERRICK CHARRON ๏ DESIGNED TO SEND SINGLE SYNCHRONOUS AND ASYNCHRONOUS REQUEST 

hollodotme/fast-cgi-client 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF WHAT I DID… 21 ๏ UPDATED PHP LANGUAGE LEVEL TO 7.X ๏ Releases v1.x for PHP 7.0.x ๏ Releases v2.x for PHP 7.1.x ๏ SPLIT CODE INTO MULTIPLE CLASSES ๏ ADDED UNIT AND INTEGRATION TESTS ๏ POLISHED THE CONNECTION, CLIENT, REQUEST & RESPONSE INTERFACES ๏ ADDED FEATURES FOR MULTI-REQUESTS AND LOOP INTEGRATION ๏ ADDED USAGE DOCUMENTATION 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF CONNECT TO UNIX DOMAIN SOCKET 22

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF PHP-FPM POOL CONFIG UNIX DOMAIN SOCKET 23 ; 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 = 5 ; Number of seconds after which an idle children will be killed pm.process_idle_timeout = 10s 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF CONNECT TO NETWORK SOCKET 24

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF PHP-FPM POOL CONFIG NETWORK SOCKET 25 ; 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 = 5 ; Number of seconds after which an idle children will be killed pm.process_idle_timeout = 10s 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF SEND A SYNCHRONOUS REQUEST 26 'value'] ); # Simulate HTTP Verbs: GET, POST, PUT, PATCH, DELETE $request = new PostRequest( '/path/to/script.php', $content ); $response = $client->sendRequest( $request ); echo $response->getBody(); 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF RESPONSE INTERFACE 27

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF ASYNC FIRE & FORGET 28 'value'] ); $request = new PostRequest( '/path/to/script.php', $content ); $requestId = $client->sendAsyncRequest( $request ); echo "Request sent, got ID: {$requestId}"; 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF ASYNC REQUEST + WAIT FOR RESPONSE 29 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(); 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF USING RESPONSE CALLBACKS 30 addResponseCallbacks( function( ProvidesResponseData $response ) { echo $response->getBody(); } ); # Failure callbacks expects a \Throwable instance # ...variadic function $request->addFailureCallbacks( function ( \Throwable $throwable ) { echo $throwable->getMessage(); } ); $requestId = $client->sendAsyncRequest( $request ); 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF USING RESPONSE CALLBACKS 31 waitForResponse( $requestId ); # Inner loop # ... is the same as while(true) # Outer loop { if ( $client->hasResponse( $requestId ) ) { $client->handleResponse( $requestId ); break; } } 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - ORDERED RESPONSES 32 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"; } 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - ORDERED RESPONSES 33 # PRINTS Response #1 Response #2 Response #3 ๏ NO MATTER HOW LONG EACH WORKER TOOK TO RESPOND 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE RESPONSES 34 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 '.'; } 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE RESPONSES 35 hasUnhandledResponses() ) { $readyRequestIds = $client->getRequestIdsHavingResponse(); # read all ready responses foreach ( $readyRequestIds as $requestId ) { $response = $client->readResponse( $requestId ); echo $response->getBody() . "\n"; }
 echo '.'; } 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - ORDERED RESPONSES 36 # PRINTS .....Response #2 .......Response #3 ..........Response #1 ๏ ORDERED BY RESPONSE TIME 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MULTIPLE REQUESTS - REACTIVE CALLBACKS 37 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 ); } } 

USE CASES 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF MESSAGE QUEUE WORKERS 39 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF TRIGGER API - PDF CREATION 40 $documentId, #... ] ); $request = new PostRequest( '/pdf-generator.php', $content ); # Delegate heavy PDF generation to another PHP process $client->sendAsyncRequest( $request ); # Immediate respond to client with generated document ID header('Content-type: application/json', true, 200); echo json_encode( ['documentId' => $documentId] ); 

QUESTIONS? 

THANK YOU! github.com/hollodotme @hollodotme / @F9T3ch fortuneglobe.com phpug-dresden.org @phpugdd HOLGER WOLTERSDORF icehawk.github.io speakerdeck.com/hollodotme Slides available at: 

ASYNC PHP REQUESTS AND REACTIVE RESPONSES WITH PHP-FPM • MAY 31st 2017 • Péhápkaři. • PRAGUE HOLGER WOLTERSDORF LINKS / REFERENCES 43 ๏ PHP USERGROUP DRESDEN e.V. http://phpug-dresden.org ๏ PHP Developer Day 2017: https://bit.ly/PHPDD17EN ๏ 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 ๏ 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