Hands on with Ruby and MongoDB

Transcript

1. Hands on with MongoDB Ruby & ^ Austin on Rails ˒ October 27, 2009 WYNNNETHERLAND Wednesday, October 28, 2009
2. Wednesday, October 28, 2009
3. No SQL? x x Wednesday, October 28, 2009
4. When does NOSQL make sense? ★Your data is stored and retrieved mainly by primary key, without complex joins. ★You have a non-trivial amount of data, and the thought of managing lots of RDBMS shards and replication failure scenarios gives you the fear. http://www.metabrew.com/article/anti-rdbms-a-list-of-distributed-key-value-stores/ Wednesday, October 28, 2009
5. Key value stores Project Voldemort Ringo Scalaris Kai Dynomite MemcacheDB ThruDB CouchDB Cassandra HBase Hypertable Redis Tokyo Cabinet/Tyrant http://www.metabrew.com/article/anti-rdbms-a-list-of-distributed-key-value-stores/ Some very cool projects in this space Wednesday, October 28, 2009
6. Tokyo Cabinet: Popular with Rubyists, Big in Japan Wednesday, October 28, 2009
7. Tokyo Cabinet: Popular with Rubyists, Big in Japan ★Lightning fast ★Works best for at objects ★Tokyo Tyrant for network access http://www.igvita.com/2009/02/13/tokyo-cabinet-beyond-key-value-store/ Wednesday, October 28, 2009
8. More document-oriented solutions Wednesday, October 28, 2009
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10. CouchDB Apache CouchDB is a distributed, fault-tolerant and schema-free document-oriented database accessible via a RESTful HTTP/JSON API. http://couchdb.apache.org/ Wednesday, October 28, 2009
11. Erlang + Javascript Wednesday, October 28, 2009
12. Map + reduce Wednesday, October 28, 2009
13. Very cool Wednesday, October 28, 2009
14. Plenty o’ Ruby to go around Wednesday, October 28, 2009
15. Ruby libraries for CouchDB CouchRest Basic model RelaxDB CouchPotato CouchFoo ActiveCouch http://www.slideshare.net/brianthecoder/couchdb From the Austin on Rails talk Wednesday, October 28, 2009
16. Document stores: Throw out everything you learned about DB design almost* * more on this later Wednesday, October 28, 2009
17. SQL CouchDB Prede ned, explicit schema Dynamic, implicit schema Uniform tables of data Collection of named documents with varying structure Normalized. Objects spread across tables. Duplication reduced. Denormalized. Docs usually self contained. Data often duplicated. Must know schema to read/write a complete object Must know only document name Dynamic queries of static schemas Static queries of dynamic schemas http://damienkatz.net/files/What is CouchDB.pdf http://damienkatz.net/files/What is CouchDB.pdf Wednesday, October 28, 2009
18. SQL CouchDB Prede ned, explicit schema Dynamic, implicit schema Uniform tables of data Collection of named documents with varying structure Normalized. Objects spread across tables. Duplication reduced. Denormalized. Docs usually self contained. Data often duplicated. Must know schema to read/write a complete object Must know only document name Dynamic queries of static schemas Static queries of dynamic schemas http://damienkatz.net/files/What is CouchDB.pdf http://damienkatz.net/files/What is CouchDB.pdf The devil's in the details Wednesday, October 28, 2009
19. Wednesday, October 28, 2009
20. because this is BIG Wednesday, October 28, 2009
21. Wednesday, October 28, 2009
22. Runs like Hayes. Hits like Mays. Wednesday, October 28, 2009
23. MongoDB x Wednesday, October 28, 2009
24. Let's just skip to here already! x Wednesday, October 28, 2009
25. Introducing ★Built For Speed ★Dynamic Queries and Indexes ★Replication and Failover ★Sharding ★Map / Reduce can be very fast Wednesday, October 28, 2009
26. MongoDB is great for ★Websites ★Caching ★High volume, low value ★High scalability ★Storage of program objects and JSON stash the hash Wednesday, October 28, 2009
27. Not as great for ★Highly transactional ★Ad-hoc business intelligence ★Problems requiring SQL Wednesday, October 28, 2009
28. Installation ★mkdir -p /data/db ★download pre-built for OSX and unzip to /usr/local/ ★cp -R /usr/local/pathtomongo/bin /usr/local/bin ★sudo gem install mongo ★sudo gem install mongo_ext ★sudo gem install mongo_mapper Native C extensions ( go turbo! ) Ruby driver for MongoDB Wednesday, October 28, 2009
29. Contents of mongo/bin ★mongod - The MongoDB server ★mongo - the JavaScript interactive shell ★mongoexport - export data as JSON or csv ★mongoimport - As advertised ★mongodump - Like mysqldump ★mongorestore - Restore from mongodump les ★mongos - Auto-sharding module (getting better with every build) what's in the box? why? What did you think it was? Wednesday, October 28, 2009
30. Some new terms Wednesday, October 28, 2009
31. When I say database Wednesday, October 28, 2009
32. When I say database think database Wednesday, October 28, 2009
33. Well that one isn't new... When I say database think database Wednesday, October 28, 2009
34. Databases in MongoDB ★Made up of multiple collections ★Are created on-the- y when rst referenced Wednesday, October 28, 2009
35. When I say collection Wednesday, October 28, 2009
36. When I say collection think table Wednesday, October 28, 2009
37. Collections in MongoDB ★Schema-less ★For grouping documents into smaller query sets (speed) ★Indexable by one or more key ★Are created on-the- y when rst referenced ★Capped collections: Fixed size, older records dropped after limit reached but typed! Wednesday, October 28, 2009
38. When I say document Wednesday, October 28, 2009
39. When I say document think record or row Wednesday, October 28, 2009
40. Document ★Stored in a collection ★Can have _id key that works like primary keys in MySQL ★Supports relationships: subdocument or db reference Wednesday, October 28, 2009
41. Document Storage (BSON) { author: 'joe', created: Date('03-28-2009'), title: 'Yet another blog post', text: 'Here is the text...', tags: [ 'example', 'joe' ], comments: [ { author: 'jim', comment: 'I disagree' }, { author: 'nancy', comment: 'Good post' } ] } http://www.mongodb.org/display/DOCS/BSON Wednesday, October 28, 2009
42. Document Storage (BSON) { author: 'joe', created: Date('03-28-2009'), title: 'Yet another blog post', text: 'Here is the text...', tags: [ 'example', 'joe' ], comments: [ { author: 'jim', comment: 'I disagree' }, { author: 'nancy', comment: 'Good post' } ] } http://www.mongodb.org/display/DOCS/BSON Sure wish JSON did this... Wednesday, October 28, 2009
43. Document Storage (BSON) { author: 'joe', created: Date('03-28-2009'), title: 'Yet another blog post', text: 'Here is the text...', tags: [ 'example', 'joe' ], comments: [ { author: 'jim', comment: 'I disagree' }, { author: 'nancy', comment: 'Good post' } ] } http://www.mongodb.org/display/DOCS/BSON Sure wish JSON did this... B is for Binary Wednesday, October 28, 2009
44. That looks like JSON Wednesday, October 28, 2009
45. So does this jason.to_json Wednesday, October 28, 2009
46. Where's the Ruby? Wednesday, October 28, 2009
47. Querying db.collection.find({'first_name': 'John'}) # finds all Johns db.collection.find({'first_name': /^wynn/i}) # regex db.collection.find_first({'_id':1}) # finds first with _id of 1 db.collection.find({'age': {'$gte': 21}}) # finds possible drinkers db.collection.find({'author.first_name':'John'}) # subdocument db.collection.find({$where:'this.age >= 6 && this.age <= 18'}) Wednesday, October 28, 2009
48. Querying $in, $nin, $all, $ne, $gt, $gte, $lt, $lte, $size, $where :fields (like :select in active record) :limit, :offset for pagination :sort ascending or descending [['foo', 1], ['bar', -1]] count and group (uses map/reduce) db.collection.mapReduce(mapfunction,reducefunction[,options]); More Wednesday, October 28, 2009
49. 10 Gen projects on the hub ★mongo-ruby-driver http://github.com/mongodb/mongo-ruby- driver ★mongorecord http://github.com/mongodb/mongo-activerecord- ruby Wednesday, October 28, 2009
50. MongoMapper ★Mongo is not MySQL ★DSL for modeling domain should also teach you Mongo ★It sounded fun ★Just released version 0.5.6 from @jnunemaker Wednesday, October 28, 2009
51. MongoMapper ★Mongo is not MySQL ★DSL for modeling domain should also teach you Mongo ★It sounded fun ★Just released version 0.5.6 from @jnunemaker I voted for "Nunemapper" Wednesday, October 28, 2009
52. Features ★Typecasting ★Callbacks (ActiveSupport Callbacks) ★Validations ★Connection and database can differ per document ★Create and Update with single or multiple ★Delete and Destroy and _all counterparts ★Find: id, ids, :all, : rst, :last ★Associations Be careful. Ordering can be tricky. Wednesday, October 28, 2009
53. Example class User include MongoMapper::Document key :name, String, :required => true, :length => 5..100 key :email, String, :required => true, :index => true key :age, Integer, :numeric => true key :active, Boolean, :default => true one :address many :articles end class Address include MongoMapper::Document key :street, String key :city, String key :state, String, :length => 2 key :zip, Integer, :numeric => true, :length => 5 end Included as module, not subclassed (this may change soon). Wednesday, October 28, 2009
54. MongoDB fun ★Capped collections (think memcache, actually used for replication) ★Upserts db.collection.update({'_id':1}, {'$inc': {'views':1}}) ★Multikeys (think tagging and full text search) ★GridFS and auto-sharding Wednesday, October 28, 2009
55. So, is it ready for Prime Time? ★Disqus ★SourceForge ★TweetCongress, GovTwit -- Floxee.com ★TweetSaver.com ★Mozilla Ubiquity Herd Ask these folks! Wednesday, October 28, 2009
56. Lessons learned in production ★The laws of computing are still in effect ★Indexes are important no matter what the salesman told ya about performance ★Data modeling. Deep or Wide? ★MongoDB and MongoMapper are in active development the fine print The answer is yes! Very responsive yet very volatile changes! Wednesday, October 28, 2009
57. How can you help? ★We need an awesome admin GUI ★Port some plugins (might get easier with ActiveModel support coming soon) ★Build something cool Wednesday, October 28, 2009
58. Resources http://mongodb.org http://www.10gen.com http://groups.google.com/group/mongomapper http://groups.google.com/group/mongodb-user http://squeejee.com http://wynnnetherland.com and thanks for having me! Questions? I'm @pengwynn on Twitter the very new blog the very cool company behind MongoDB Wednesday, October 28, 2009