Object Graph Mapping with Spring Data Neo4j 3

Object Graph Mapping Spring Data Neo4j 3.0 Nicki
Wa( @ opencredo Michael Hunger @ neotechnology

Agenda 1. Why Object-‐Graph-‐Mapping? 2. What is
Spring Data (Neo4j)? 3. Current State of aﬀairs 4. SDN 3.0 5. The Future 6. Some Spring Data Neoj Use-‐Cases

1. Why Object-‐Graph-‐Mapping?

Why OGM ? -‐ Convenience -‐ Simplify
interac2on with underlying data source: Framework/Library handles basic CRUD type funcVonality for you -‐ Provides ability to work with na2ve domain language constructs: eg domain classes/objects (POJOs in Java) in your applicaVon -‐ Use Cases: examples at end of talk

Why OGM ? But … -‐  IndirecVon, addiVonal
abstracVon layer adds performance, overhead -‐  Encourages users to pull larger parts of the database into memory to process instead of le_ng the db do its job

2. What is Spring Data Neo4j?

Spring Data Neo4j -‐ OGM aimed at Java world
& uses Spring -‐ Neo4j Implementa2on of the Spring Data project: SpringSource/VMWare/Pivotal iniVaVve to give Spring developers easy access to the emerging world of NOSQL. Was the iniVal and ﬁrst Spring Data project by Rod and Emil -‐ Simple programming model: annotaVon-‐based programming for applicaVons with rich domains

With and without SDN ...

Spring Data Neo4j -‐ features -‐ Two mapping modes:
Simple & Advanced -‐ Provides Spring Data Repository Support -‐ Ability to drop down to Neo4j Core API if required -‐ (Neo4j Server Support)

Example Domain: “Conference Management”

Sample graph

High Level Object Model

DePining Your Entities

SDN Domain Entities @NodeEntity @TypeAlias(value = "Conference")
public class Conference { @GraphId Long graphId; @Indexed String name; Date date; @RelatedTo(type="ATTENDEE") Set<Person> attendees; @RelatedTo(type="TALK") Set<Talk> talks; // . . . }

SDN Domain Entities @NodeEntity @TypeAlias(value = "Person")
public class Person { @GraphId Long graphId; @Indexed(unique = true) String name; @RelatedToVia Iterable<Attended> talksAttended; // . . . }

SDN Domain Entities (Relationship) @RelationshipEntity(type = "LISTENED_TO") public
class Attended { @GraphId Long graphId; @StartNode Person attendee; @EndNode Talk talk; Integer rating; // . . . }

SDN Domain Entities @NodeEntity @TypeAlias(value = "Talk")
public class Talk { @GraphId Long graphId; @Indexed String name; String description; @RelatedTo(type="SPEAKER") Set<Speaker> speakers; @RelatedToVia(direction = INCOMING) Set<Attended> attendees; // . . . }

SDN Domain Entities @TypeAlias(value = "Speaker") public class
Speaker extends Person { String bio; @RelatedTo(type="SPEAKER", direction = INCOMING) Iterable<Talk> talks; // . . . }

SDN Repository Support -‐ Derived Finder Methods

SDN Repository Support import org....data.neo4j.repository.GraphRepository; import java.util.Set;
public interface TalkRepository extends GraphRepository<Talk> { Set<Talk> findTalksBySpeakersName(String name); }

@NodeEntity @TypeAlias(value = "Talk") public class Talk {
@GraphId Long graphId; @Indexed String name; String description; @RelatedTo(type="SPEAKER") Set<Speaker> speakers; @RelatedToVia(direction = INCOMING) Set<Attended> attendees; // . . . } SDN Repository Support ﬁndTalksBySpeakersName

SDN Repository Support ﬁndTalksBySpeakersName @TypeAlias(value = "Speaker")
public class Speaker extends Person { String bio; @RelatedTo(type="SPEAKER", direction = INCOMING) Iterable<Talk> talks; // . . . } @NodeEntity @TypeAlias(value = "Person") public class Person { @GraphId Long graphId; @Indexed(unique = true) String name; @RelatedToVia(type="ATTENDED") Iterable<Attended> talksAttended; // . . . }

public interface TalkRepository extends GraphRepository<Talk> { Set<Talk> findTalksBySpeakersName(String name); } START `talk_speakers`=node:`Person`(`name`={0}) MATCH (`talk`)-‐[:`SPEAKER`]-‐>(`talk_speakers`) RETURN `talk`

SDN Repository Support -‐ Dynamic Queries

public interface TalkRepository extends GraphRepository<Talk> { // Repository Query Method @Query(value = "MATCH (talk:Talk)-‐[:SPEAKER]-‐>(speaker:Speaker) " + "WHERE speaker.name={0} RETURN talk") Set<Talk> findTalksBySpeakersNameQuery(String name); // . . . }

3. Current State Of Affairs

Current State Of Affairs -‐ Current ProducVon Version: 2.3.2.RELEASE
-‐ Neo4j 1.9.3 support

4. SDN 3.0

Disclaimer !!

Disclaimer SDN 3.0 s)ll in progress ... • 
Subject to change •  Primary changes are Neo4j 2.0 compliance -‐ not ﬁnalised yet •  follow progress on githubh"p:// spring.neo4j.org/source

SDN 3.0 -‐ Base Neo4j 2.0 support -‐
Spring 3.2.5 (eventually 4 as well) support -‐ New Type Representa2on Strategy -‐ Labels -‐ Migra2on towards more Cypher driven founda2on -‐ Various bug ﬁxes and enhancements

Neo4j 2.0 Support -‐ Will be able to
run against a Neo4j 2.X DB -‐ Query using Labels -‐ Ability to use new Cypher Syntax -‐ Schema Indexes (Work in Progress)

Label Type Representation Strategy

@NodeEntity @TypeAlias(value = "Person") public class Person {
@Query("MATCH (person)<-‐[:ATTENDEE]-‐(gathering:Conference)" + " WHERE id(person) = {self} " + " RETURN gathering") public Iterable<Conference> findAllConferencesAttended; // . . . } @NodeEntity @TypeAlias(value = "Conference") public class Conference { // . . . }

@TypeAlias(value = "Speaker") public class Speaker extends Person {
String bio; @RelatedTo(type="SPEAKER", direction = INCOMING) Iterable<Talk> talks; // . . . } @NodeEntity @TypeAlias(value = "Person") public class Person { @GraphId Long graphId; @Indexed(unique = true) String name; @RelatedToVia(type="ATTENDED") Iterable<Attended> talksAttended; // . . . }

Index vs Label TRS public interface ConferenceRepository extends
GraphRepository<Conference> { /* Query generated when using Index Based TRS START `conference`=node:__types__(className="Conference") WHERE `conference`.`date` = {0} RETURN `conference` Query generated when using Label Based TRS MATCH (`conference`:`Conference`) WHERE `conference`.`date` = {0} RETURN `conference` */ Set<Conference> findAllByDate(Date date); }

-‐ Will allow for schema indexes** to be used
-‐ Will add addiVonal __TYPE__XX labels to nodes -‐ No addiVonal properVes need to be stored on nodes to represent hierarchy (If Index Based TRS used) -‐ No addiVonal nodes need to be created to represent hierarchy (If Sub Reference based TRS used) Label Type Representation Strategy

5. The Future

Future Plans -‐ Cypher based •  Use all Cypher
for the mapping layer •  Align embedded and remote use •  Beneﬁt from Cypher enhancements •  Leverage complex query mechanisms •  Support more OGM type funcVonality •  Client side caching •  Lazy loading

Future Plans -‐ OGM •  PotenVally extract or use
standalone, cypher-‐based Java-‐Neo4j-‐OGM •  Also useable without Spring (Data)

Future Plans -‐ Query Results •  Project query results
into object trees/graphs •  Useful for direct view-‐layer integraVon •  Less overhead by an intermediate domain model that has to be converted

Future Plans -‐ Support •  Be(er support for
•  Spring Boot •  Spring Data Rest •  Remote transacVonal integraVon •  JDBC-‐Driver in Spring

Future Plans -‐ Migration •  Migrate Type RepresentaVon
•  Index-‐based -‐> Label based •  Refactor/Rename EnVVes, Fields, References •  Rename Indexes •  @TypeAlias

6. Some Use Cases

WhyOwnIt: Ownership Sharing Service

WhyOwnIt: Ownership Sharing Service •  Sharing Culture
•  You own things you only seldomly need •  You need things you don‘t own •  Match needs and available devices/tools •  add raVngs, trust, recommendaVons •  locaVon based, close to you for pick-‐up •  Startup

WhyOwnIt: Ownership Sharing Service

Music Sharing/Discovery/Recommendation Service

Music Sharing/Discovery/Recommendation Service •  Recommend new arVsts and
songs to your users •  take their previous listen-‐history into account •  look at what‘s hot amongst their friends •  infer broader selecVon via bands and genres •  Detect duplicates using media-‐ﬁngerprints •  copyright infringements

Music Sharing/Discovery/Recommendation Service

Other Use-‐Cases

Other Use-‐Cases •  Financial Services -‐ Asset / Account
Management •  Bank -‐ Permission Management and AuthorizaVon •  EnVtlement •  Data Sopware Provider -‐ Impact analysis of changes •  ImplicaVon of changes on the company core asset: DATA •  Change tracking •  Root Cause Analysis

•  Networked Storage Boxes •  many components, disks, controllers,
power supply, sensors •  Tracking of measurement data •  Impact analyVcs •  Early detecVon of anomalies •  Intelligent fail over •  Huge number of domain enVVes (~450) •  generaVng domain classes and repositories SAN/NAS Provider -‐ Lifetime device tracking

Game Retailer •  Buy and Download & Game on
Demand •  Fraud detecVon •  delayed payments, charge backs, fradulent keys are invalid •  Convert rules to traversals •  co-‐occurrance of sudden large sales •  fradulent e-‐mail pa(erns •  CombinaVon with Oracle Infrastructure •  Cross-‐Store

Does it love me or does it not?

Domain-‐Centric •  Integrate in a Springframework Context • 
ExisVng ApplicaVons with POJO Domains •  Move a manageable amount of data in and out of the database into Domain Objects •  Rich, connected domain •  MulVple projecVons To SDN or Not to SDN ...

Data-‐Centric •  high volume database interacVons •  reads
and writes (inserts) •  thin domain view on top of graph queries •  remote Client to Neo4j Server To SDN or Not to SDN ...

Want More Info ?

•  Spring Data Book •  Spring Data Neo4j
Guidebook •  Spring Data Neo4j on Spring.io •  Chapter in Neo4j in AcVon •  Cineasts.net Tutorial Resources

Thanks ☺ Questions ? @techiewa(
@mesirii

Object Graph Mapping with Spring Data Neo4j 3

Object Graph Mapping with Spring Data Neo4j 3

More Decks by Nicki Watt

Other Decks in Technology

Featured

Transcript