CELUM set out to develop its own reactive graph driven architecture to provide the best user experience for workrooms.net. Hear our story on how we ventured into the areas of Graph Databases, Data Modelling as well as Reactive Programming and melted them into a graph-centred reactive architecture. We put it to the test and built our production-ready cloud-based enterprise application atop it. Learn about lofty goals and unexpected surprises that we managed to turn into happy endings. Building upon our experiences will become your edge once you develop your own graph-centric cloud application. The unique aspects presented are a type-safe query language atop Gremlin available within back-end and front-end, our inheritance-aware data model and the seamless streaming of graph data to the front-end as it becomes available. Finally, drawing upon these capabilities, we look at Live Queries that notify clients when query results become stale and thus both improve the UX and reduce the system load.

1. BUILDING A PRODUCTION-READY, GRAPH-BASED
ENTERPRISE APPLICATION IN THE CLOUD
RAINER PICHLER, SOFTWARE ARCHITECT
https://twitter.com/rainerpichler
AN INNOVATION STORY TOLD BY

2. III. Where we go
AN INNOVATION STORY*
*inspired by the Gartner Hype Cycle

3. WHO WE ARE
PREFACE

4. &
Turn content into value
Change how people collaborate
CONTENT
HUB
AGILE TEAMWORK
MANAGEMENT
OUR MISSION

5. OUR CHALLENGES
Scale globally
Our users are data modelers
&

6. BACK IN 2016

7. WHAT WE EXPECTED
CHAPTER I

8. OUR EXPECTATIONS
Customizability
Reactivity
Scalability

10. ESSENTIALS FOR EFFICIENT TEAMWORK
Free Trial? Visit workrooms.net!

11. OUR DOMAIN (EXCERPT)
2.097.152
5.242.880
Fast local navigation
Intuitive Data Modelling
Load stuff on demand
Rainer
Rene
Catalogue
Winter
Pictures
Products.docx
Draft.psd
Logo.tiff
Bike.tiff
moderator
moderator
524.288
2.048
Inbox
Free Trial? Visit workrooms.net!

12. WHAT WE GOT
CHAPTER II

13. OUR ARCHITECTURE
EB - API
ENTITY DATA MODEL
PERSISTENCE
Domain
Service
Domain
Service
Domain
Service
EB - CLIENT
ENTITY DATA MODEL
View View View
Service Service Service
Angular
RxJS
Flux
Graph Database
RxJava
Vert.x
celum.com

14. FULL-STACK-REACTIVE
Channel
Database
1
234
5C
Query all Workrooms

15. FULL-STACK-REACTIVE

16. FULL-STACK-REACTIVE

17. THE ECOSYSTEM
CELUM Persistence Layer
JanusGraph
Process
Apache Cassandra
Process
23
16
42
16
23
42
<binary>
<binary>
<binary>
16
42
23
Apache TinkerPop + Gremlin

18. MORE DETAILS
https://www.youtube.com/watch?v=9ZXCHqip84Q&feat
ure=youtu.be&t=1h32m12s
Technologieplauscherl 56 (English)
Exploring the JanusGraph Database using
the Gremlin Query Language

19. THE CELUM PERSISTENCE LAYER
Entity Data Model
Query and Modification Language
Id=16
16
42
23
8 15
16 23
Result
Filter

20. MODEL DEFINITION

21. MODEL DEFINITION
Eclipse Modeling Framework
TypeScript
Java
PlantUML

22. MODEL DEFINITION
public interface ContentItemType extends AnyEntityType {
public static final Name NAME = new Name();
public static final CreationDate CREATIONDATE = new CreationDate();
public static final ModifiedDate MODIFIEDDATE = new ModifiedDate();
/** Description: Determines the primary sort order in the UI */
public static final SortIndex SORTINDEX = new SortIndex();

23. OUR QUERY AND MODIFICATION LANGUAGE
Type-safety
Uniform on BE & FECommon functionalities
Type inheritance
g.V().has("type_folder", "folder")Pure Gremlin:

24. A QUERY
Query<ContentElementType> query =
Query.fromEntitiesOfType(FolderType.instance())
.restrict(R.attributeValue(FolderType.NAME, AttributeMatcher.equalTo(“Pictures”)))
.followRelationsOfType(ContainerHasElementsRelationType.instance()).build();
Rainer
Rene
Catalogue
Winter
Pictures
Products.docx
Draft.psd
Logo.tiff
Bike.tiff
moderator
moderator
524.288
2.048
Inbox
g.V().has("type_folder", "folder")
.has("name", "Pictures")
.out("containerHasElements")

25. STATIC TYPE SAFETY
[Folder] [ContentElement]
.followRelationsOfType(ContainerHasElements)Query.fromEntitiesOfType(Folder) .restrict([…])
<File>
ID: 42
Name: Logo.tiff
<Folder>
ID: 23
Name: Pictures
<ContainerHasLeafElements>
ID: 37
instance of instance of instance of
.build()
EntityQueryBuilder QueryEntityQueryBuilder
Steps
[ContainerHasElements]

26. TYPE MISMATCHES

27. Channel
THE QUERY PIPELINE
Split Query Optimize Translate Traverse Emit
Security
C*
Steps
Pictures
Logo.tiff
Bike.tiffPictures Logo.tiff
Bike.tiff
Gremlin
g.V()…
Cassandra
Query.from…

28. THE MODIFICATION PIPELINE
Optimize Translate Traverse EmitCommit
Constraints
CRUD Tracking
C*
Gremlin
g.V()…
__.sideEffect(traverser -> {
if (!allowed(traverser.get()))
throw new RuntimeException("Computer says no!");
});
Cassandra
Steps
Modification.of…

29. TOOLING
The elegance of the query reflects in the mighty CodeMirror.

30. The result graph
becomes visible due to
an unsung rendering
hero: PlantUML

31. LEARNINGS
Replicate if the use case demands it.
Replicate if the use case demands it.
Replicate if the use case demands it.

32. LEARNINGS
Relations as First Class Citizens
✔
✘
✘
✘

33. LEARNINGS
Granularity of Results

34. LEARNINGS
Write once, run anywhere?
CELUM Persistence Layer
JanusGraph
Custom
Java
Code Arbitrary Gremlin Server
CELUM Persistence Layer
Pure Gremlin?

35. WHERE WE GO
CHAPTER III

36. Constraints & Clean-ups
Controlled Redundancy
Schema Evolution
Model is Key

37. UPCOMING: LIVE QUERIES
Goal: UI always up-to-date
Live Queries in the CELUM Reactive Server Platform
Master Thesis by Florian Latifi (florian.latifi@jku.at)
Johannes Kepler University Linz
We will blog about it on celum.com

38. And CELUM keeps
extending its platform.
Always ahead.
* The End *