Palestra sobre implementações paralelas feita na Locaweb e no GuruSP.

1. Implementações paralelas
Willian Molinari
a.k.a PotHix

2. WTF

3. 1996!!
John Carmack

4. https://github.com/id-Software

5. #AltDevBlogADay

6. Várias formas de
implementações paralelas

7. 1. Substitution

8. Master

9. Código no branch principal
class VirtualMachine
def name
hypervisor_session.VM.get_name(uuid)
end
.
.
.
end

10. Código código no branch novo
class VirtualMachine
def name
on_hypervisor.VM.get_name(uuid)
end
.
.
.
end

11. Master NewFeature
Feature

12. "Virar a chave"

14. Dá para evitar?

15. 2. Feature Toggle

16. 2. Feature Toggle
Para adição de funcionalidade

17. Martin Fowler
http://martinfowler.com/bliki/FeatureToggle.html

18. Master
Feature1
Merge Release
Feature2
Feature3

19. Martin Fowler
http://martinfowler.com/bliki/FeatureToggle.html

20. Nando Vieira
http://simplesideias.com.br/usando-presenters-no-rails/

21. 2. Feature Toggle
Para várias implementações

22. Fabio Kung
http://fabiokung.com/2010/10/16/dsls-one-interface-multiple-implementations/

23. Qual a idéia?

24. module Resque
class Consumer
class << self
def queue(name)
@queue = name
end
def timeout(seconds=nil)
@lock_timeout = seconds unless seconds
@lock_timeout || 1.hour
end
def exclusive(param)
@exclusive = param
self.extend(Resque::Plugins::LockTimeout) if exclusive?
@lock_timeout ||= 1.hour
end
def publish(message={})
Resque.enqueue(self, message)
end
...
end
end
end

25. module ActiveMQ
class Consumer
class << self
attr_reader :queue_name, :queued_process, :headers, :timeout_value
def queue(name)
@queue_name = "/queue/#{name}"
end
def timeout(seconds)
@timeout_value = seconds
end
def exclusive(param)
@exclusive = param
end
def publish(message = {})
client = Stomp::Client.new(NephelaeConfig[:broker].merge(:max_reconnect_attempts => 1))
client.publish(queue_name, message.to_yaml, {
:persistent => true, :suppress_content_length => true
})
end
...
end
end
end

26. require 'xmpp4r'
module XMPP
class Consumer
class << self
attr_reader :queue_name, :queued_process, :timeout_value
def queue(name)
@queue_name = "#{name}@localhost"
end
def timeout(seconds)
@timeout_value = seconds
end
def exclusive(param)
@exclusive = param
end
def publish(message={})
publisher_client.send(Jabber::Message.new(queue_name, message.to_yaml))
end
...
end
end
end

27. app/consumers/consumer.rb
Consumer = ActiveMQ::Consumer

28. app/consumers/consumer.rb
Consumer = XMPP::Consumer

29. app/consumers/consumer.rb
Consumer = Resque::Consumer

30. Injeção de dependencia
MyQueue.new(Resque::Consumer)

31. Por configuração

32. 3. Feature versioning

33. Manager
Ver1 Ver2

34. module Network
class Ver1
def insert_filter_rule(filter_rule)
filter_rule.firewalls.in_parallel do |firewall|
ssh_executor = SSHExecutor.new(firewall.ip_address, 'sservice')
result = ssh_executor.exec(
:insert_filter_firewall_rules, :rule => filter_rule,
:internal_address => filter_rule.ip_pair.private_ip,
:firewall => firewall
)
raise "Insertion failed: #{result[:out]}" if result[:status] != 0
end
filter_rule.update_attribute(:status, :done)
end
def insert_dhcp_entry(vm)
vm.zone.dhcps.in_parallel do |dhcp_server|
result = dhcp_server.synchronize
raise "DHCP failed: #{result[:out]}" if result[:status] != 0
end
end
end
end

35. Manager
Ver1 Ver2

36. module Network
class Ver2
def insert_filter_rule(filter_rule)
quantum = Openstack::QuantumClient::L2l3.new(NephelaeConfig[:quantum])
quantum_response = quantum.filter_rule.create(
filter_rule.filter_address,
filter_rule.ip_pair.public_ip.to_s,
filter_rule.filter_port,
filter_rule.filter_protocol
)
filter_rule.update_attribute(:quantum_uuid, quantum_response["filter_rule"]["id"])
end
def insert_dhcp_entry(vm)
quantum = Openstack::QuantumClient::L2l3.new(NephelaeConfig[:quantum])
quantum_response = quantum.dhcp_entry.create(vm.public_ip.to_s, vm.mac, vm.name)
end
end

37. Manager
"1.0" "2.0"
Ver1 Ver2

38. module Network
module Manager
extend self
def for(versioning_object)
versioning_object.version == "2.0" ? Network::Ver2.new : Network::Ver1.new
end
end
end

39. module Network
module Manager
extend self
def for(versioning_object)
versioning_object.version.constantize.new
end
end
end
Network::Manager.for(pool).insert_filter_rule(virtual_machine)

40. Várias formas de
atacar o problema
r bu llet
os ilve
N
Resumindo
Su bene fício
an
ec Cu sto X
es
sida
de

41. Perguntas?