A reworking of the infamous "CouchDB Perform Like a Pron Star" presentation, done for the Maine Ruby User Group

1. CouchDB
Perform like a frAg star
Casey Rosenthal
Maine Ruby Users Group
Slides by Renae Bair

2. How do you identify
a developer/frAg star?

3. size
- memory usage
- amount of servers
- infrastructure

4. reliability

5. fault-tolerant
- no downtime
- ready for traffic peaks
- ready for more data

6. plays well with others

7. plays well with others
- public interfaces
- no discrimination

8. scalability

9. scalability
- reaction under load
- handle concurrent connections
- number of requests/s
- latency

10. performance

11. ¿frAg star?

12. kinda!

13. CouchDB
Apache’s Document-Oriented Database

14. Relational Database
Management Systems

15. Relational Database
Management Systems
Data Columns
Relationships Tables
Data Rows

16. RDBMS
table name
primary key structured data
scalar values column name
SQL consistency
integrity constraints

17. RDBMS
challenges for the web
- most/all fields become optional
- many-to-many relationships
- joins
- replication
- auto incremental ids

18. RDBMS
scaling is a pain

19. Column Oriented DBMS
Hypertable
Bigtable

20. Distributed Hash Table
node B
Key/Value
node C
Key/Value node A
Key/Value node M
Key/Value
node L
Key/Value
node Z
Key/Value

21. Distributed Hash Table
-decentralized
-add/remove nodes ➟ scale
-fault tolerant
-p2p & IM
-memcached
-memcached ➟ disk
-MemcacheDB
-Project Voldemort
-Scalaris
-Tokyo Cabinet
-Redis

22. CouchDB

23. CouchDB

24. key/value
store
CouchDB
Key: "user-077-socialsecuritynumber"
value: "477-289-4690"

25. decentralized
CouchDB

26. replication
CouchDB

27. replication
CouchDB

28. fault tolerant
CouchDB

29. compute data
CouchDB
map/reduce built-in

30. compute data
CouchDB
function(doc) {
if (doc.type == 'Card' && doc.tags) {
doc.tags.forEach(function(tag){
emit(tag, 1);
})
}
}

31. more tricks

32. full ACID
compliance

33. HTTP
REST interface

34. Load Balancing

35. Caching

36. conflict management

37. MVCC
Multiversion concurrency control

38. couchdb-lucene
http://github.com/rnewson/couchdb-lucene/

39. ruby

40. couchrest

41. core
couch = CouchRest.new("http://127.0.0.1:5984")
db = couch.database!('GoGaRuCo')
db.save_doc({
'type' => 'attendee',
'first_name' => 'John',
'last_name' => 'Doe',
'age' => 32,
'tags' => ['Merb', 'MacRuby', 'JS']
})

42. more
class Card < CouchRest::ExtendedDocument
include CouchRest::Validation
use_database SERVER.default_database
property :first_name
property :last_name, :alias => :family_name
property :pid, :read_only => true
timestamps!
validates_present :first_name
end

43. more
Card.first
Card.all
Card.by_first_name(:key => 'Matt')
Card.by_last_name(:keys => ['Aimonetti','Vega'])
Card.get('matt_aimonetti')
Card.by_phone_number( :startkey => [760,{}],
:endkey => [815,{}])

44. more
property :questions, :cast_as => ['Question']
property :professor, :cast_as => 'Person'
property :final_test_at, :cast_as => 'Time'

45. more
view_by :date, :descending => true
view_by :user_id, :date

46. more
view_by :tags,
:map =>
"function(doc) {
if (doc['couchrest-type'] == 'Article' && doc.tags) {
doc.tags.forEach(function(tag){
emit(tag, 1);
});
}
}",
:reduce =>
"function(keys, values, rereduce) {
return sum(values);
}"

47. more
save_callback :before, :generate_slug_from_title

48. when to use couch?
-when you need to scale your DB
-when availability is more important than
consistency
-when your data is decentralized
-when you need to compute data

49. Thanks