Mongodb on Ruby And Rails (froscon 2010)

on rails

froscon 2010, st. augustin.

jan krutisch <[email protected]>http://jan.krutisch.de/

Sonntag, 22. August 2010

mailto:[email protected]


http://jan.krutisch.de


mongodb wtf? lol!?


document database


document database

NoSQLincluded!


10gen


open source

http://github.com/mongodb/mongo


http://github.com/leshill/mongodoc


id title descr pos_lat pos_lng


no fixed schemano migrations


rich data structure


{ "_id" : ObjectId("4c00245062610475a005afcd"), "address" : "Bernstorffstr. 174\n22767 Hamburg\nDE", "description" : null, "position" : { "lat" : 53.5600912, "lng" : 9.9596977 }, "tags" : [ "hausarzt", "naturheilverfahren", "akupunktur", "allgemeinmedizin" ], "title" : "Dr. med. Lilo Eisenbarth", "loxicon_id" : 808261 }


✗Sonntag, 22. August 2010

BSON


BInary Serialized jsON

http://bsonspec.org/Sonntag, 22. August 2010

http://bsonspec.org

http://bsonspec.org

Lightweight


Traversable


Efficient


Wire


Storage


rich queries


conceptually close to SQL


easy to grasp


flexible


language integration


on top: map/reduce


Scaling


Master/Slave replication


Replica Sets (1.6)


Primary

Member Member


Prim

ary

Member Primary


Member

Member Primary


Autosharding (1.6)


Durability


No single server durability!


fsyncs every 60s(configurable)


Use Replication!


Use write propagation locking


Single Server Durability planned for 1.8


mongo console


$ mongo


> use testswitched to db test

db.quotes.save({ text: "You can observe a lot just by watching.", from: "Yogi Berra", created_at: new Date() });

db.quotes.save({ text: "Silence is one of the hardest arguments to refute.", from: "Josh Billings", created_at: new Date() });


Indexing


Same concept as with SQL databases


You want them


Same concept as with SQL databases


Sort order


Unique


Compound


Geospatial


map/reduce


we can haz it, too


function() { this.tags.forEach(function(z) { emit(z, {count: 1}); }); }

function(key, values) { var total = 0; values.forEach(function(v) { total += v }); return {count: total} }


(it‘s not fast...)


security


simple user/password auth


per database


read only is possible


one more thing


GridFS


Binary fields in BSON < 4MB


GridFS saves files in chunks


I‘m in u‘r rubies,querying teh MongoDB!


core driver


mongo / bson_ext


ODMs / Libs


mongo_mapper


mongoid


Find examples here:http://github.com/halfbyte/mongo_ruby_examples


http://github.com/halfbyte/mongo_ruby_examples


Basic driver usage


init


require 'mongo'

@connection = Mongo::Connection.new@db = @connection.db("test")


insert/upsert


doc = { :text => "You can observe a lot just by watching.", :from => "Yogi Berra", :created_at => Time.now}@db['quotes'].insert(doc)


doc = @db['quotes'].find_one(id)

doc[:from] = "Yogi Berra, famous baseball player"

@db['quotes'].save(doc)


atomic updates


@db['quotes'].update( {"from" => "Yogi Berra"}, {"$inc" => {"reads" => 1 } })


$inc$set$unset$push$pushAll

$addToSet$pop$pull$pullAll$


getting a whole collection


@db['quotes'].find.each do |row| puts row.inspectend


exact query


@db['quotes'].find(:from => "Yogi Berra")


more queries


100.times do |i| db['numbers'].insert({"i" => i})end


db['numbers'].find("i" => {"$lt" => 2})


$lt <$gt >$lte <=$gte >=$ne !=


@db['people'].find(:tags => {"$in" => ['cool']})


obj = { "_id"=>BSON::ObjectID('4c706af16261040680000369'), "name"=>"Vernon Kreiger", "address"=>{ "street"=>"536 Haleigh Locks", "city"=>"Port Kiannahaven", "zip"=>"80730-0214", "country"=>"Fakistan" }, "tags"=>["cool", "weird"]}


$in IN (2,3,4)$nin NOT IN$all [2,3] ~ [1,2,3]


$mod yah, RLY$size okay$exists NOT NULL$type huh?


@db['people'].find("address.city" => /haven/)


Sorting


@db['people'].find().sort("address.street")


Pagination


@db['numbers'].find.sort("i").limit(10)


@db['numbers'].find.sort("i").limit(10).skip(50)


Counting


@db['numbers'].find.count


Distinct


@db['people'].distinct('tags').inspect


Group


Poor mans map/reduce


Map / Reduce


map = <<-END function() { this.tags.forEach(function(z) { emit(z, {count: 1}); }); }ENDreduce = <<-END function(key, values) { var total = 0; values.forEach(function(v) { total += v.count }); return {count: total} }END

collection = @db['people'].map_reduce( map, reduce)


Indexes


db['people'].create_index("tags")

db['people'].drop_index("tags_1")

db['people'].index_information


GridFS usage


grid = Mongo::Grid.new(@db)

id = grid.put("You can put Strings in here", :filename => 'test.txt')

file = grid.get(id)

file.filenamefile.read

grid.delete(id)

grid.put( File.open("/Users/jankrutisch/Dropbox/Photos/IMGP8989.jpg"))


fs = Mongo::GridFileSystem.new(db)

fs.open("test.txt", "w") do |f| f.write "You can put stuff in here"end

fs.open("test.txt", "r") do |f| puts f.readend

fs.delete("test.txt")


Capped collections


@db.create_collection('capped_numbers', :capped => true, :max => 50)

@db.create_collection('capped_numbers', :capped => true, :size => 1024 * 64)


ODMs


mongo_mapper


John Nunemaker@jnunemaker


is in production


documentation?


how to


rails initializer


# config/initializers/mongo_mapper.rbFile.open(File.join(Rails.root, 'config/mongodb.yml'), 'r') do |f| @settings = YAML.load(f)[Rails.env]end

MongoMapper.connection = Mongo::Connection.from_uri(@settings["connection"]) if @settings["connection"]

MongoMapper.database = @settings["database"]


a simple example


MongoMapper.connection = @connectionMongoMapper.database = "test"

class Quote include MongoMapper::Document key :from key :text key :views, Integer timestamps!end


finders


Quote.where(:from => 'Yogi Berra').all

Quote.where(:from => 'Yogi Berra').limit(5).sort(:from.desc).all


embedded docs


class Person include MongoMapper::Document key :name one :address key :tags, Arrayend

class Address include MongoMapper::Document key :street key :city key :country key :zipend


person = Person.firstaddress = Person.first.address


scopes


class Person scope :tagged, lambda { |tag| where(:tags.in => [tag]) }end

puts Person.tagged('cool').first.inspect


new website coming soon


mongoid


Durran Jordan(of Hashrocket)


Two major versions


1.x (1.9.x) targeting Rails 2.3.x


2.x (2.0beta) targeting Rails 3.0


Good documentation


rails initializer


File.open(File.join(RAILS_ROOT, 'config/mongodb.yml'), 'r') do |f| @settings = YAML.load(f)[RAILS_ENV]end

Mongoid::Config.instance.from_hash(@settings)


a simple example


class Quote include Mongoid::Document include Mongoid::Timestamps field :from field :text field :views, :type => Integerend


finders


Quote.where(:from => 'Yogi Berra').all

Quote.where(:from => 'Yogi Berra').limit(5).order_by(:from.desc).all


embedded docs


class Person include Mongoid::Document field :name embeds_one :address field :tags, :type => Arrayend

class Address include Mongoid::Document field :street field :city field :country field :zipend


person = Person.firstaddress = Person.first.address


scopes


class Person scope :tagged, lambda { |tag| where(:tags.in => [tag]) }end

puts Person.tagged('cool').first.inspect


More features


atomic updates


mongoid tries to be clever


(using the „dirty“ flags)


(it‘s probably better to bypass the ODM sometimes)


GridFS


external libraries for both


mongo_mapper > grip


mongoid > mongoid_grid


Other noteworthy libraries


Candy


mongodoc





mongo-record

http://github.com/mongodb/mongo-record




mongomodel

http://github.com/spohlenz/mongomodel




mongo_queue

http://github.com/Skiz/mongo_queue




resque-mongo

http://github.com/ctrochalakis/resque-mongo




my account


Installation was easy


(when on right platform)


setting up replication


$ mongod --masterormaster = true # mongodb.conf

$ mongod --slave --source slaveserver.example.com

slave = truesource = slaveserver.example.com


(see example on github)


OpLog size!


„security“


memory usage?


limits?


stability?


I ♥


thanks for listening.

‣ [email protected]‣ http://jan.krutisch.de/‣ http://github.com/halfbyte/‣ http://twitter.com/halfbyte‣ http://www.mindmatters.de/

‣ http://www.mongodb.org/‣ http://www.mongoid.org/‣ http://github.com/jnunemaker/mongo_mapper‣ http://github.com/halfbyte/mongo_ruby_examples






http://github.com/halfbyte/

http://github.com/halfbyte/

http://twitter.com/halfbyte

http://twitter.com/halfbyte

http://www.mindmatters.de

http://www.mindmatters.de

http://www.mongodb.org

http://www.mongodb.org

http://www.mongoid.org

http://www.mongoid.org

http://github.com/jnunemaker/mongo_mapper

http://github.com/jnunemaker/mongo_mapper



Mongodb on Ruby And Rails (froscon 2010)

Technology

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