GraphAwareTM

Building High Performance Applications with Spring Data Neo4j 4

Vince Bickers, GraphAware

graphaware.com

@graph_aware

Agenda● A bit about Neo4j and the Spring Data project

● A brief history of SDN

● SDN 4: Spring Data + Standalone Java OGM

● Conference Demo

o Data model

o Code

o Live demo!

● Roadmap

● Q & A

Neo4j is a Graph Database•Nodes & Edges (Relationships)

• Index-free adjacency means super-fast traversals

•Embedded Client and Remote Server

•Schema-flexible!

•Cypher Query Language

When worlds collide…The impedance mismatch

Spring Data

•Most active Spring Project

•Consistent APIs to access both RDBMS and NoSQL stores

• JPA, Neo4j, MongoDB, Redis, CouchBase…

•Convenient abstractions for Spring developers

Quick History of SD-Neo4j● SDN 0.x - Rod and Emil wrote it, started Spring Data efforts

● SDN 1.x - Embedded Neo4j, Object Mapping, Templates

● SDN 2.x - Neo4j Server, SD-Repositories

● SDN 3.x - Neo4j 2.x with Label + Schema Index Support, etc.

Now… Spring Data Neo4j 4.0● New and Shiny!

o Complete rewrite

o Neo4j Server only (for now, at least)

o Sympathetic to typical business use cases

o And … not just for Spring developers!

Spring Data Neo4j 4 - Progress● Development started Sep 2014

● Milestone 1 released end Mar 2015

● RC1 end-May 2015

● GA … mid-June 2015

Spring Data + Separate OGM● Standalone Java OGM

● Spring+

o Template methods

o Transactions

o Repositories

o Queries

o Exception Translation

o Conversion Services

Approach● Constraint: Cypher over HTTP

● Solution: Focus on performance!

Core OGM - Features● "Vampire" Metadata scanning (no reflection!)

● Optional annotations

● Mapping contexts scoped to “conversational” lifetimes:

o Application,

o HTTP session,

o HTTP request, etc.

● "Smart" object-mapping

● Variable-depth persistence

Variable-depth persistence

If you're interested in loading this...

...you're often really interested in this

Variable-depth persistenceIf your domain objects are connected….…you should be able to save them all at once - from any object.

Conference Application

Spring Data Neo4j 4.0 Spring Boot Angular.js

Application architectureStraightforward Spring Boot application:

● RESTControllers

● … depending on Services

● …... depending on Spring Repositories

● to persist POJO Entity classes

Entities and RelationshipsEntities (Labels)

● Speaker

● Conference

● Track

● Talk (Session)

● Timeslot

Relationships

● PRESENTS

● REGISTERED_FOR

● IN_TRACK

● HAS_TRACK

● AT_TIMESLOT

Conference Graph Model

Speaker

Conference

Track

Session

Timeslot

PRESENTS

REGISTERED_FORHAS_TRACK

IN_TRACKAT_TIME_SLOT

Preparing the data - CQLcreate (conference:Conference {name : 'GraphConnect 2015'})

create (track1:Track {name : 'Technical Track'})

create (track2:Track {name : 'Business Track'})

create (track3:Track {name : 'Practitioner Track'})

create (track4:Track {name : 'Beginner Track'})

create (conference)<-[:REGISTERED_FOR]-(long:Speaker {name : 'Josh Long'})

create (conference)<-[:REGISTERED_FOR]-(gonzalez:Speaker {name : 'Ignasi Gonzalez'})

create (conference)<-[:REGISTERED_FOR]-(lopez:Speaker {name : 'Ivan Lopez'})

create (conference)<-[:REGISTERED_FOR]-(rodriguez:Speaker {name : 'Anton Rodriguez'})

…etc

All the data loaded…

Configuration: Spring Boot@SpringBootApplication

@Import(PersistenceConfig.class)

public class ConferenceApplication {

public static void main(String[] args) {

SpringApplication app = new SpringApplication(ConferenceApplication.class);

app.setShowBanner(false);

app.run(args);

}

}

Configuration: Persistence@Configuration @EnableNeo4jRepositories(basepackages="app.conference.repository") @EnableTransactionManagement

public class PersistenceConfig extends Neo4jConfiguration {

@Bean public Neo4jServer neo4jServer() { return new RemoteServer("http://localhost:7474"); }

@Bean public SessionFactory getSessionFactory() { return new SessionFactory("app.conference.domain"); }

@Bean @Scope(value="session", proxyMode=ScopedProxyMode.TARGET_CLASS) public Session getSession() throws Exception { return super.getSession(); } }

Entities: Abstract Entity@JsonIdentifyInfo(generator=JSOGGenerator.class)

public abstract class Entity {

@JsonProperty("id") @GraphId private Long id;

private String name;

}

Entities: Speakerpublic class Speaker extends Entity { @Relationship(type="PRESENTS") private Set<Talk> talks; }

Entities: Talk @NodeEntity(label="Session")

public class Talk extends Entity {

@Relationship(type="AT_TIMESLOT") private Timeslot timeslot;

@Relationship(type="IN_TRACK") private Track track;

@Relationship(type="PRESENTS", direction=Relationship.INCOMING) private Set<Speaker> presenters;

}

Repositoriesinterface SpeakerRepository extends GraphRepository<Speaker> {

@Query("MATCH(s:Speaker)-[:PRESENTS]->() return s, count(*) as hits ORDER BY hits DESC")

Iterable<Map<String,Object>> speakersByNumberOfTalks();

}

Services - abstraction

public abstract class GenericCRUDService<T> implements Service<T> {

private static final int DEPTH_LIST = 0; private static final int DEPTH_ENTITY = 1;

@Override public Iterable<T> findAll() { return getRepository().findAll(DEPTH_LIST); }

@Override public T find(Long id) { return getRepository().findOne(id, DEPTH_ENTITY); }

public abstract GraphRepository<T> getRepository();

}

Services - implementation@Service

public class SpeakerService extends GenericCRUDService<Speaker> {

@Autowired private SpeakerRepository repository;

@Override public GraphRepository<Speaker> getRepository() { return repository; }

}

Controllers - abstraction@RequestMapping(value = "/api")

public abstract class Controller<T> {

public Iterable<T> list() { return getService().findAll(); }

public T create (T entity) { return getService().createOrUpdate(entity); } // … more controller methods here

public abstract Service<T> getService();

}

Controllers - implementation// controller methods get an @ResponseBody annotation by default, yay!

@RestController public class TalkController extends Controller<Talk> {

@Autowired private TalkService service;

@RequestMapping(value="/talks", method = RequestMethod.GET) public Iterable<Talk> list() { return service.findAll(); } }

Front end: Angular js ● Very simple CRUD application

● Loosely based on jHipster angular templates

● Each JSON entity (track, speaker, etc) fully supported by 5 files:

o config.js

o servicefactory.js

o controllers.js

o list.html

o detail.html

DemoConference Application

Where next?Immediately after RC1:

● Project code split

● General release mid-June

● More features planned

o Dynamic Properties

o Support for Embedded Neo4j

o Versioning (MVCC)

o Automatic hooks to pre/post-save lifecycle events

o Binary protocol …etc.

Getting startedNeo4j: http://neo4j.com/download

SDN4 Conference Application: https://github.com/neo4j-examples/sdn4-conference

Spring Data Neo4j (4)

Current Release: http://maven.springframework.org/milestone/org/springframework/data/spring-data-neo4j/4.0.0.M1

Latest Build: http://repo.spring.io/libs-snapshot/org/springframework/data/spring-data-neo4j/4.0.0.BUILD-SNAPSHOT

Code: https://github.com/spring-projects/spring-data-neo4j/tree/4.0

Documentation: http://docs.spring.io/spring-data/neo4j/docs/4.0.0.M1

GraphAwareTM

Getting help

Luanne Misquitta

Adam George

Vince Bickers

Want to track/raise an issue?

○ https://jira.spring.io/browse/DATAGRAPH

Got questions, or need some advice?

○ Check our blog:http://graphaware.com/blog/

○ Stack Overflow is your friend

graphaware.com

@graph_aware