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Titan:db Scaling Relationship Data with C*

Matthias Broecheler @mbroecheler September XI, MMXIV

#CassandraSummit

Storing relationship data in Cassandra entails data denormalization or pointer chasing inside the application which reduces developer productivity, is error prone, and slow due to lack of optimization. Titan:db exposes a property graph data model directly atop Cassandra which makes storing and querying relationship data fast, easy, and scalable to huge graphs. This talk demonstrates how Titan's features enable complex, multi-relational databases in Cassandra and discusses customer use cases for recommendation and personalization engines.

Multi-Relational Data Structure

Graph

Titan = Cassandra + Graph

Titan 0.5

Cassandra

,CH?;L M=;F;<CFCNS

@;OFN NIF?L;H=?

IJ?H MIOL=?

GOFNC >;N;=?HN?L

BCAB J?L@ILG;H=?

Key   ColumnA   ColumnB   ColumnC   ColumnD   ColumnE   ColumnF  

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

User Product

CREATE INDEX ON User.username, User.email, Product.productid

CREATE INDEX ON username(User), email(User), productid(Product)

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

username   producDd   Dme  

ma7   52235   9/5/14  

billy   42215   8/7/14  

billy   42215   8/7/14  

Buy

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

What did ‘matt’ buy? Application level join

username   producDd   Dme  

ma7   52235   9/5/14  

billy   42215   8/7/14  

billy   42215   8/7/14  

Buy

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

What did ‘matt’ buy? g.V.has(‘username’,’matt’) .out(‘buy’)

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

What did ‘matt’ recently buy?

Application level join

username   producDd   Dme  

ma7   52235   9/5/14  

billy   42215   8/7/14  

billy   42215   8/7/14  

Buy

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

g.V.has(‘username’,’matt’) .outE(‘buy’).orderBy(‘time’,DESC) [0..9].inV

What did ‘matt’ recently buy?

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

What did ‘matt’ recently buy?

slow

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

g.V.has(‘username’,’matt’) .outE(‘buy’).orderBy(‘time’,DESC) [0..9].inV

username   producDd   Dme  

ma7   52235   9/5/14  

billy   42215   8/7/14  

billy   42215   8/7/14  

What did ‘matt’ recently buy?

Rewrite join logic

username   Dme   producDd  

ma7   9/5/14   52235  

billy   8/7/14   42215  

billy   8/7/14   42215  

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

What did ‘matt’ recently buy?

CREATE INDEX ON buy edges by time OUT direction

g.V.has(‘username’,’matt’) .outE(‘buy’).orderBy(‘time’,DESC) [0..9].inV

producDd   username   Dme  

52235   ma7   9/5/14  

42215   billy   8/7/14  

42215   billy   8/7/14  

Who bought ‘52235’? More application joins

producDd   Dme   producDd  

52235   9/5/14   ma7  

42215   8/7/14   billy  

42215   8/7/14   billy  

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

g.V.has(‘productid’,52235) .in(‘buy’)

CREATE INDEX ON buy edges by time IN direction

Who bought ‘52235’?

Product join tables won’t scale

username   producDd   Dme  

ma7   52235   9/5/14  

billy   42215   8/7/14  

billy   42215   8/7/14  

username   Dme   producDd  

ma7   9/5/14   52235  

billy   8/7/14   42215  

billy   8/7/14   42215  

username   email   password  

ma7   ma7@   12345  

john   john@   qwerty  

billy   billy@   abcde  

producDd   name   price  

52235   cup   12.55  

42215   spoon   7.22  

24529   knife   5.32  

producDd   username   Dme  

52235   ma7   9/5/14  

42215   billy   8/7/14  

42215   billy   8/7/14  

producDd   Dme   producDd  

52235   9/5/14   ma7  

42215   8/7/14   billy  

42215   8/7/14   billy  

User Product

productid: 52235 name: cup price: 12.55

username: matt email: matt@ password: 12345

buy time: 9/5/14

PARTITION Product Vertices

Token Ring (BOP)

Edge Cut

- assigns ids to map vertices into “optimal” token range - Maintains virtual partitions

Vertical Partitioning = divide communities

Vertex Cut

Combined Graph Partitioning

Database

Datastore

Transactions

v = g.V.has(‘username’,’matt’) .has(‘password’,’12345’) p = g.V.has(‘productid’,52235) e = v.addEdge(‘buy’,p) e.setProperty(‘time’,’9/11/2014’) o = g.addVertex([orderid:242343]) o.addEdge(‘buyer’,v) o.addEdge(‘product’,p) g.commit()

unit of work

Atomicity Consistency

Isolation Durability

Transaction Consistency

u = g.addVertex([username:’matt’]) p = g.V.has(‘username’,’senior’) u.addEdge(‘father’,p) p.setProperty(‘surname’,’Jones’) g.commit()

Locks acquired to ensure consistency constraints are enforced

•  Index Uniqueness •  Multiplicity Constraints •  Cardinality Constraints

Polyglot Data Architecture

© Jay Kreps @ LinkedIn

Transaction modifications

logged

Consumers

Titan Event Framework

Use Cases

http://arli.us/magazinaluiza

Security

Fraud

http://arli.us/cisco-sec1

© Sean York @ Pearson Education

http://bit.ly/ WPTitanSEAGraph

http://arli.us/musicgraphintro

Music Graph

Knowledge Graph

TitanDB.io

Relationships + Cassandra

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