por Juan Maiz e Pedro Axelrud

1. Otimizando Aplicações em Rails
essa palestra será rápida

2. Servidor
Active Record / SQL
Ruby / Rails
Cache
BackgrounDRb
Metal
HTML, JS & CSS

4. Nginx, Apache
balanceadores de carga

5. joeandmotorboat.com/2008/02/28/apache-vs-nginx-web-server-performance-deathmatch/

6. Mongrel, Thin, Passenger
servidores de aplicação

7. http://izumi.plan99.net/blog/index.php/2008/03/31/benchmark-passenger-mod_rails-vs-mongrel-vs-thin/

8. Active Record / SQL

9. INCLUDE
for list in List.all
... do some ...
for contact in list.contacts
... do some ...
end
end

10. INCLUDE
for list in List.all(:include => :contacts)
... do some ...
for contacts in list.contacts
... do some ...
end
end

11. ÍNDICES
Rails não adiciona índices nas
tabelas
EXPLAIN ANALYZE SELECT * FROM contacts WHERE
email = 'foo@bar.com';>> cost=0.00..25.38CREATE INDEX
contacts_email_idx ON contacts(email);>> cost=0.00..1.06

12. TABELAS CONSOLIDADAS
Newsletter#history
>> Buscava dados de mais de 100 mensagens (total de envios,
acessos, cliques, descadastros, informações geográficas...) em uma
view e apresentava um gráfico.
Tempo médio do método: 18s
CREATE TABLE messages_complete_history AS SELECT *
FROM view_messages_complete_history;
Tempo médio do método: 0.3s
>> Criação agendada para a madrugada com BackgroundRB

13. CSV EXPORT
COPY (SELECT * FROM contacts) TO 'path' WITH
DELIMITER ';' CSV HEADER
Muitas ordens de magnitude mais
rápido do que AR + FasterCSV

14. WORKING ON
postgres_timestamps plugin
sobrescreve comportamento de created_at e updated_at do
AR
cria defaults e triggers automaticamente nas migrações
benchmarks que fiz: de 2 a 5% mais rápido em 1000 inserts.
até 10% mais rápido em 1000 updates;
>> Prometo para ainda este ano!

15. Ruby / Rails

16. BENCHMARK
require 'benchmark'
Benchmark.bm do |x|
x.report('foo') { ... code ... }
x.report('bar') { ... code ... }
end

17. ||=
def calculate_something
@something = do_some_heavy_calculation
end

18. MEMOIZE
def calculate_something(*args)
do_some_heavy_calculation
end
memoize :calculate_something
calculate_something(1) #Hit
calculate_something(1) #Cache
calculate_something(1) #Cache
calculate_something(2) #Hit

19. RAILS STARTUP
# environment startup file
require 'geoip_city'
GEOIPDB = GeoIPCity::Database.new('file.dat')
# some controller or model
GEOIPDB.look_up(ip)

20. DICAS GERAIS
ids = @contacts.map(&:id) #bad
ids = @contacts.map{|c| c.id} #ugly, but good
str = str.gsub(/java/, 'ruby')#bad
str.gsub!(/java/, 'ruby') #good

21. Cache

22. PAGE CACHE
# site controller
caches_page :index

23. ACTION CACHE
# login controller
before_filter :get_client
caches_action :index

24. FRAGMENT CACHE
# some view
- cache :action_suffix => 'comments' do
= render :partial => 'comments'
# no controller...
def create_comment
...
expire_fragment :action => 'show_post',
:action_suffix => 'comments'
end

25. FRAGMENT CACHE
# some view
- cache :key => @contact.updated_at do
= render :partial => 'contact_info'
# Expira automático, mas gera alguns arquivos
...

26. HTTP CLIENT CACHE
fresh_when
:last_modified => @product.published_at.utc,
:etag => @article

27. CACHE-MONEY PLUGIN
http://github.com/nkallen/
cache-money/tree/master
>> Try it out and tell us...

28. Metal

29. METAL
class Go
def self.call(env)
if env["PATH_INFO"] =~ /^/go/view/(d+)/
id = $1
request = Rack::Request.new(env)
delivery = Delivery.find id
View.create :contact_id => delivery.
contact_id, :message_id => delivery.message_id, :ip
=> request.ip
delivery.contact.confirm!
[200, {"Content-Type" => "text/html"}, [""]]
else
[404, {"Content-Type" => "text/html"}, ["Not
Found"]]
end
end
end

30. METAL
2-5x faster
>> NÃO DEVERIA SE CHAMAR SPEED METAL?

31. BackgrounDRb

32. Pode executar tarefas em bg;
Pode agendar tarefas para
executar em bg;
Pode executar tarefas
periodicamente em bg;
Pode até conversar via TCP;

33. EXECUTANDO UMA TAREFA
class ContactsWorker < BackgrounDRb::MetaWorker
set_worker_name :contacts_worker
def delete(args)
total = args[:contacts].size
cache[:total] = total
cache[:curr] = 0
cache[:msg] = Contact.delete_many(args[:contacts]) do
cache[:curr] += 1
end
end
end
# start worker on controller
MiddleMan.worker(:contacts_worker).async_delete(:args =>
{:contacts => @contacts}, :job_key => @job_key)
# verify worker status via Ajax
t = MiddleMan.worker(:contacts_worker).ask_result(:total)
c = MiddleMan.worker(:contacts_worker).ask_result(:curr)
return render :json => [t, c]

34. EXECUTANDO UMA TAREFA
Média antes: 13s (muitas FKs!
milhares de contatos!)
Média depois: 0.1s (usuário pode
trabalhar durante processo)

35. EXECUTANDO UMA TAREFA AGENDADA
MiddleMan.worker(:messenger_worker)
.enq_send_messages(
:args => @message.id,
:scheduled_at => @message.scheduled_at,
:job_key => "message_#{@message.id}")

36. EXECUTANDO UMA TAREFA PERIÓDICA
# backgroundrb.yml
:schedules:
:table_cache_worker:
:table_cache:
:trigger_args: 0 30 4 * * * *

37. HTML, JS & CSS

38. CSS PLEASE DONT USE FONT TAG
SPRITES *
JSMIN
GZIP
HTTP CLIENT CACHE (304!)
return render :nothing => true, :status => 304

39. Cloud Storage e CDN
static.mailee.me