Getting started with MongoDB and Scala Open Source Bridge June 27 2012 Portland Oregon

1. Getting started with
MongoDB and Scala
Open Source Bridge
June 27, 2012
Sean Sullivan

3. Gilt Groupe

5. Gilt Portland

6. http://twitter.com/tinyrobots/status/217675630962163713

7. Jobs @ Gilt Portland
• QA engineering
• Backend engineering
• Frontend engineering
#scala #java #ruby #html5 #javascript

8. open source @ Gilt

11. • MongoDB
• Using Mongo and Scala together
• MongoDB at Gilt

12. “MongoDB is a document-oriented
database management system
designed for performance, horizontal
scalability, high availability, and
advanced queryability”
source: http://docs.mongodb.org/manual/about/

13. http://www.mongodb.org

14. https://github.com/mongodb/mongo

15. Licensing
Database: GNU AGPL v3.0
Drivers: Apache License 2.0
source: http://www.mongodb.org/display/DOCS/Licensing

16. Getting started

17. http://www.mongodb.org/downloads

18. http://www.mongodb.org/downloads

19. MongoDB concepts

20. MySQL MongoDB
database database
table collection
index index
row BSON document
column BSON field
join embedding and linking
primary key _id field
group by aggregation
source: mongodb.org

21. http://www.mongodb.org/display/DOCS/BSON

22. Embedding vs Linking
“Embedding is the nesting of objects and arrays inside a
BSON document”
“Links are references between documents”
source: http://www.mongodb.org/display/DOCS/Schema+Design

23. MongoDB on MacOS X
$ wget http://downloads.mongodb.org/osx/mongodb-osx-x86_64-2.0.6.tgz
$ tar -zxvf mongodb-osx-x86_64-2.0.6.tgz
$ sudo mkdir -p /data/db
$ sudo chown `id -u` /data/db

24. Starting MongoDB
$ mongod

25. Mongo shell
$ mongo

26. Mongo shell demo

27. Mongo shell
> use mydb
> obama = { name: “Obama” };
> db.presidents.save(obama);
> db.presidents.ensureIndex({ name: 1 });
> db.presidents.find({name: “Obama”});
> exit

28. Client libraries for the JVM

29. • mongo-java-driver • Casbah
• Morphia • Hammersmith
• Rogue

30. MongoDB Java driver

31. https://github.com/mongodb/mongo-java-driver/

32. mongo-java-driver
and Maven
<dependency>
<groupId>org.mongodb<groupId>
<artifactId>mongo-java-driver<artifactId>
<version>2.8.0<version>
<dependency>

33. mongo-java-driver
example code

34. Morphia

35. http://code.google.com/p/morphia/

36. Morphia example code

37. Casbah

38. https://github.com/mongodb/casbah/

39. Casbah
• Scala toolkit for MongoDB
• built on top of the mongo-java-driver

40. Casbah
• Scala idioms
• Scala collections
• fluid query syntax

41. https://twitter.com/mongodb/status/217291079920254976

42. Casbah and Maven
<dependency>
<groupId>org.mongodb<groupId>
<artifactId>casbah_2.9.2<artifactId>
<version>2.3.0<version>
<dependency>

43. Casbah and SBT
"org.mongodb" %% "casbah" % "2.3.0"

44. Casbah DBObject
import org.mongodb.casbah.Imports._
val mongoConn = MongoConnection(hostname, port)
val mongoDB = mongoConn(“test_db”)
val collection = mongoDB(“test_data”)
val newObj = MongoDBObject(“a” -> “apple”, “b” -> “banana”)
newObj += “c” -> “chocolate”
val a = newObject.getAs[String](“a”)
// a is an Option[String]
http://api.mongodb.org/scala/casbah/current/tutorial.html

45. Casbah MongoDBList
// MongoDBList is a Mongo-friendly Scala List
import org.mongodb.casbah.Imports._
val builder = MongoDBList.newBuilder
builder += "foo"
builder += "bar"
builder += "x"
builder += "y"
val newLst = builder.result
/* newLst: com.mongodb.BasicDBList = [ "foo" ,
"bar" , "x" , "y"] */
http://api.mongodb.org/scala/casbah/current/tutorial.html

46. Querying with Casbah
val mongoColl = MongoConnection()("test_db")("users")
val user1 = MongoDBObject("user" -> "barack",
"email" -> "barack@whitehouse.gov")
val user2 = MongoDBObject("user" -> "someOtherUser")
mongoColl += user1
mongoColl += user2
mongoColl.find()
// com.mongodb.casbah.MongoCursor =
// MongoCursor{Iterator[DBObject] with 2 objects.}
for { x <- mongoColl} yield x
/* Iterable[com.mongodb.DBObject] = List(
{ "_id" : { "$oid" : "4c3e2bec521142c87cc10faa"} ,
"user" : "obama" ,
"email" : "barack@whitehouse.gov"},
{ "_id" : { "$oid" : "4c3e2bec521142c87dc10fbb"} ,
"user" : "someOtherUser"}
) */
http://api.mongodb.org/scala/casbah/current/tutorial.html

47. Fluid querying with Casbah DSL
val q = "email" $exists true
// q: (String, com.mongodb.DBObject) =
// (email,{ "$exists" : true})
val users = for (x <- mongoColl.find(q))
yield x
assert(users.size == 1)
http://api.mongodb.org/scala/casbah/current/tutorial.html

48. Hammersmith

49. https://github.com/bwmcadams/hammersmith

50. Hammersmith
• new MongoDB driver for Scala
• pure Scala
• Asynchronous
• Not production ready at this time

51. MongoDB at Gilt

52. • feature configuration service
• global navigation service
• user service

53. Foursquare’s Fongo project

54. “Fongo is an in-memory java implementation of mongo.”
“[...] primary use is for lightweight unit testing where you
don't want to spin up a mongo process”

55. https://github.com/foursquare/fongo

56. Additional resources
• http://www.10gen.com/presentations
• http://www.mongodb.org
• http://www.slideshare.net/sullis

57. Questions?

58. THE END