Discovering graph structures

Graph is a mathematical construct used to model the relationships between key/value pairs, comprises a set of vertices (nodes) and an arbitrary number of edges (lines) which connect them. There are many ways to implement graphs with PHP, from typical SQL solutions to dedidacted, powerful tools like Apache Giraph or Titan. In this talk I will introduce Neo4j, highly scalable and robust native graph database, used in mission-critical apps by thousands of leading startups, enterprises and governments around the world. We will also talk about managing nodes and traversing methods with PHP.

Transcript

1. DISCOVERING GRAPH STRUCTURES Mariusz Gil
2. ABOUT ME
3. DEVELOPER / TECH-LEAD / CONSULTANT
5. INSPIRATION IS BETTER THAN SOLUTION
6. DATA
7. CRUCIAL VERY THING IN YOUR APP
8. CRUCIAL MOST THING IN YOUR APP STORING PROCESSING
9. 90+
10. WHY?
11. 90+ HYPOTHESIS
12. dev developers struct set list tree graph … SQL(struct)
13. WE ALL SPEAK SQL* * INCLUDING 3NF THIS IS OUR WAY TO WORK WITH DATA
14. 7MB QUERY
15. STORING PROCESSING
16. 90+ HYPOTHESIS EXTENDED
17. dev developers struct set list tree graph … SQL(JSON(struct))
22. GRAPHS
23. POWERFUL SINCE 1736
24. C A GRAPH = (VERTICES, EDGES) B
25. C A SPARSE GRAPH B D C A COMPLETE GRAPH B D C A DENSE GRAPH B D ADJACENCY LIST ADJACENCY MATRIX
26. DIGRAPH = (VERTICES, DIRECTED EDGES) C A B
27. type: KNOWS VERTICES AND EDGES PROPERTIES B type: NOTHING A type: PERSON name: John Snow
28. GRAPHS IN REAL LIFE
30. Open In progress Resolved Reopened Closed
31. task_id task_status 1 1 2 3 3 2 4 4 Open In progress Resolved Reopened Closed
32. use Finite\StatefulInterface; class Document implements StatefulInterface { private $state; public function setFiniteState($state) { $this->state = $state; } public function getFiniteState() { return $this->state; } }
33. use Finite\StateMachine\StateMachine; use Finite\State\State; use Finite\State\StateInterface; // $document = retrieve your stateful object $sm = new StateMachine(); // Define states $sm->addState( new State('s1', StateInterface::TYPE_INITIAL) ); $sm->addState('s2'); $sm->addState('s3'); $sm->addState( new State('s4', StateInterface::TYPE_FINAL) );
34. s4 s3 s2 // Define transitions $sm->addTransition('t12', 's1', 's2'); $sm->addTransition('t23', 's2', 's3'); $sm->addTransition('t34', 's3', 's4'); $sm->addTransition('t42', 's4', 's2'); // Initialize $sm->setObject($document); $sm->initialize(); // Retrieve current state $sm->getCurrentState(); // Can we process a transition? $sm->can('t34'); s1
35. HUNDREDS TRANSITIONS TENS OF MODELS ONE ACTION DRY HUNDREDS OF THOUSANDS OBJECTS IN DB
36. /** * @Route("/change-state") */ public function changeStateAction() { // Get model // ... // Check user permissions // ... // Check transition and notify observers if ($model->isTransitionAllowed($targetState) { $model->setState($targetState); // Save change // ... } // Finish // ... }
37. E C G F B A D H I J K L M
38. E C G F B A D H I J 1:30 1:30 1:00 1:45 0:45 0:45 3:00 1:15 1:00 0:40 0:20 0:30 0:30 K L M
39. @tom @bob @john #php #js #web Tweet X search tweet retweet favourite contains search search search follow follow search contains search
40. require_once 'vendor/autoload.php'; use \Fhaculty\Graph\Graph as Graph; $graph = new Graph(); // Create some cities $rome = $graph->createVertex('Rome'); $madrid = $graph->createVertex('Madrid'); $cologne = $graph->createVertex('Cologne'); //Bbuild some roads $cologne->createEdgeTo($madrid); $madrid->createEdgeTo($rome); // create loop $rome->createEdgeTo($rome); // Process foreach ($rome->getVerticesEdgeFrom() as $vertex) { echo $vertex->getId().' leads to rome’ . PHP_EOL; }
41. require_once 'vendor/autoload.php'; $graph = new Fhaculty\Graph\Graph(); $blue = $graph->createVertex('blue'); $blue->setAttribute('graphviz.color', 'blue'); $red = $graph->createVertex('red'); $red->setAttribute('graphviz.color', 'red'); $edge = $blue->createEdgeTo($red); $edge->setAttribute('graphviz.color', 'grey'); $graphviz = new Graphp\GraphViz\GraphViz(); $graphviz->display($graph);
42. SEARCH SHORTEST PATH SPANNING TREES TRAVELING SALESMAN PROBLEM MAXIMUM FLOW MINIMUM COST FLOW MAXIMUM MATCHING ALGORITHMS
43. TYPICAL SQL-WAY C A B mysql> SELECT * FROM `nodes`; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | +----+------+ 3 rows in set (0,00 sec) mysql> SELECT * FROM `edges`; +--------+--------+ | s_node | e_node | +--------+--------+ | 1 | 2 | | 2 | 3 | | 3 | 1 | +--------+--------+ 3 rows in set (0,00 sec) CREATE TABLE `nodes` ( `id` int(11) NOT NULL auto_increment, `name` varchar(64) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB; CREATE TABLE `edges` ( `s_node` int(11) NOT NULL, `e_node` int(11) NOT NULL, PRIMARY KEY (`s_node`,`e_node`), ) ENGINE=InnoDB;
44. TYPICAL SQL-WAY C A B mysql> SELECT * FROM `nodes`; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | +----+------+ 3 rows in set (0,00 sec) mysql> SELECT * FROM `edges`; +--------+--------+-------+ | s_node | e_node | float | +--------+--------+-------+ | 1 | 2 | 6.50 | | 2 | 3 | 4.75 | | 3 | 1 | 10.00 | +--------+--------+-------+ 3 rows in set (0,00 sec) CREATE TABLE `nodes` ( `id` int(11) NOT NULL auto_increment, `name` varchar(64) NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB; CREATE TABLE `edges` ( `s_node` int(11) NOT NULL, `e_node` int(11) NOT NULL, `weight` float NOT NULL, PRIMARY KEY (`s_node`,`e_node`), ) ENGINE=InnoDB; 10.00 6.50 4.75
46. LARGE MEDIUM SMALL
47. GRAPH ORIENTED DATABASE
48. INSTALL
49. SINGLE NODE SETUP wget -O - http://debian.neo4j.org/neotechnology.gpg.key | apt-key add - echo 'deb http://debian.neo4j.org/repo stable/' > /etc/apt/sources.list.d/neo4j.list apt-get update apt-get install neo4j service neo4j-service status LINUX EDITION
51. RUN
53. QUERY
55. LIVE DEMO
56. require_once 'vendor/autoload.php'; use Neoxygen\NeoClient\ClientBuilder; $client = ClientBuilder::create() ->addConnection('default') ->setAutoFormatResponse(true) ->build(); $query = 'MATCH (n)-[r]->(m) RETURN *'; $nodes = $client->sendCypherQuery($query) ->getResult() ->getNodes(); foreach ($nodes as $node) { echo sprintf( "%s %s:" . PHP_EOL, $node->getLabel(), $node->getProperty("name") ); }
58. http://graphdatabases.com
59. ALTERNATIVES
63. TOOLS WILL CHANGE IDEAS ARE IMMORTAL
64. Dijkstra's algorithm is an algorithm for finding ______________ in graph
65. @mariuszgil THANKS! https://joind.in/14886