Building Cloud Castles - LRUG
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The document is a presentation by Ben Scofield discussing various aspects of cloud computing and related practices, emphasizing issues like reliability, costs, and the need for proper coding practices. It includes examples and code snippets related to handling cloud storage, managing application errors, and defensive coding methods. The presentation highlights that cloud applications tend to prefer simplicity and seeks to explain cloud architecture patterns and virtues.
![LOCAL
$ ssh deploy@production.server.com
Linux production.server #1 SMP Sat Dec 5 16:04:55 UTC 2009 i686
To access official Ubuntu documentation, please visit:
http://help.ubuntu.com/
Last login: Fri Jan 28 16:33:49 2011 from local.host
deploy@production:~$ cd /var/log/apache2
deploy@production:/var/log/apache2$ tail error.log
[Sun Jan 23 06:25:02 2011] [notice] Apache/2.2.12 (Ubuntu) Phusion_Passenger...
[Tue Jan 25 15:21:42 2011] [error] [client 118.129.166.97] Invalid URI in ...
[Fri Jan 28 12:01:50 2011] [error] [client 85.132.70.133] client sent HTTP/1...
[Sun Jan 30 06:25:06 2011] [notice] SIGUSR1 received. Doing graceful restart](https://image.slidesharecdn.com/201104-lrug-110411170034-phpapp01/85/Building-Cloud-Castles-LRUG-7-320.jpg)
![CLOUD
$ heroku logs --remote production
2011-04-11T01:34:22-07:00 app[web.1]: Rendered text template within layout...
2011-04-11T01:34:22-07:00 app[web.1]: Completed 200 OK in 54ms
2011-04-11T01:34:30-07:00 app[web.3]: Rendered text template within layout...
2011-04-11T01:34:30-07:00 app[web.3]: Completed 200 OK in 111ms (Views:57....
2011-04-11T08:34:42+00:00 heroku[router]: GET devcenter.heroku.com/article...
2011-04-11T01:34:42-07:00 heroku[nginx]: GET /articles/facebook HTTP/1.0 |...
2011-04-11T01:34:42-07:00 app[worker.1]: [Worker(host:railgun64.53370 pid:...
2011-04-11T01:34:42-07:00 app[worker.1]: [Worker(host:railgun64.53370 pid:...](https://image.slidesharecdn.com/201104-lrug-110411170034-phpapp01/85/Building-Cloud-Castles-LRUG-9-320.jpg)
![CLOUD
class Comic < ActiveRecord::Base
has_attached_file :cover, :storage => s3,
:s3_credentials => {
:access_key_id => ENV['S3_KEY'],
:secret_access_key => ENV['S3_SECRET']
},
:bucket => 'comicsapp',
:url => ":s3_path_url",
:s3_headers => { 'Expires' => 1.year.from_now.httpdate },
:styles => {
:thumb => "80x120>",
:medium => "300x450>"
}
end](https://image.slidesharecdn.com/201104-lrug-110411170034-phpapp01/85/Building-Cloud-Castles-LRUG-20-320.jpg)
![CLOUD
class Searcher
cattr_accessor :index
def self.index
@api ||= IndexTank::Client.new(ENV['INDEXTANK_API_URL'])
@index = @api.indexes 'articles'
end
def self.search(term)
raw = self.index.search(term, :function => 1)
results = raw['results'].to_a
article_ids = results.map {|result| result['docid'] }
unsorted = Article.published.where(:id => article_ids)
results.map { |result|
unsorted.find {|u| u.id.to_i == result['docid'].to_i}
}.compact
end
end](https://image.slidesharecdn.com/201104-lrug-110411170034-phpapp01/85/Building-Cloud-Castles-LRUG-38-320.jpg)
![CLOUD
class Searcher
# ...
def self.search(term)
results = begin
raw = self.index.search(term, :function => 1)
raw['results'].to_a
rescue URI::InvalidURIError # An IndexTank error occurred
search_by_sql(term)['results']
end
# ...
end
def self.search_by_sql(term)
{'results' => Article.where(['content ILIKE ?', "%#{term}%"]).
map {|a| {'docid' => a.id}}}
end
end](https://image.slidesharecdn.com/201104-lrug-110411170034-phpapp01/85/Building-Cloud-Castles-LRUG-40-320.jpg)
Building Cloud Castles - LRUG
- 1. BUILDING CLOUD CASTLES ben scofield / @bscofield / LRUG / 11 April 2011
- 2. this presentation is a WORK IN PROGRESS http://www.flickr.com/photos/natlockwood/1006351276/
- 4. not just
- 5. the cloud allows LIMITED ACCESS
- 7. LOCAL $ ssh deploy@production.server.com Linux production.server #1 SMP Sat Dec 5 16:04:55 UTC 2009 i686 To access official Ubuntu documentation, please visit: http://help.ubuntu.com/ Last login: Fri Jan 28 16:33:49 2011 from local.host deploy@production:~$ cd /var/log/apache2 deploy@production:/var/log/apache2$ tail error.log [Sun Jan 23 06:25:02 2011] [notice] Apache/2.2.12 (Ubuntu) Phusion_Passenger... [Tue Jan 25 15:21:42 2011] [error] [client 118.129.166.97] Invalid URI in ... [Fri Jan 28 12:01:50 2011] [error] [client 85.132.70.133] client sent HTTP/1... [Sun Jan 30 06:25:06 2011] [notice] SIGUSR1 received. Doing graceful restart
- 8. NODE NODE NODE NODE NODE NODE NODE NODE
- 9. CLOUD $ heroku logs --remote production 2011-04-11T01:34:22-07:00 app[web.1]: Rendered text template within layout... 2011-04-11T01:34:22-07:00 app[web.1]: Completed 200 OK in 54ms 2011-04-11T01:34:30-07:00 app[web.3]: Rendered text template within layout... 2011-04-11T01:34:30-07:00 app[web.3]: Completed 200 OK in 111ms (Views:57.... 2011-04-11T08:34:42+00:00 heroku[router]: GET devcenter.heroku.com/article... 2011-04-11T01:34:42-07:00 heroku[nginx]: GET /articles/facebook HTTP/1.0 |... 2011-04-11T01:34:42-07:00 app[worker.1]: [Worker(host:railgun64.53370 pid:... 2011-04-11T01:34:42-07:00 app[worker.1]: [Worker(host:railgun64.53370 pid:...
- 12. source
- 13. FIXING PROBLEMS
- 14. LOCAL $ ssh deploy@production.server.com Linux production.server #1 SMP Sat Dec 5 16:04:55 UTC 2009 i686 To access official Ubuntu documentation, please visit: http://help.ubuntu.com/ Last login: Fri Jan 28 16:33:49 2011 from local.host deploy@production:~$ cd /var/www/app/current/ deploy@production:/var/www/app/current$ rails console production Loading production environment (Rails 3.0.3) >> Article.count => 112 >> Article.where(:problem => true).update_attributes(:problem => false)
- 15. CLOUD require 'test_helper' class ArticleTest < ActiveSupport::TestCase context 'Broken articles' do setup do 5.times.do { Factory :broken_article } end should 'be fixable' do assert_equal 5, Article.where(:problem => true).count Article.fix_problem_articles assert_equal 0, Article.where(:problem => true).count end end end class Article def self.fix_problem_articles where(:problem => true).update_attributes(:problem => false) end end
- 17. LOCAL class Comic < ActiveRecord::Base has_attached_file :cover, :styles => { :thumb => "80x120>", :medium => "300x450>" } end $ cd public/system $ ls /covers 10/ 12/ 53/ 81/ $ ls /covers/10/ medium/ original/ thumb/ $ ls /covers/10/medium batman-450.png
- 18. NODE NODE NODE NODE NODE NODE NODE NODE
- 20. CLOUD class Comic < ActiveRecord::Base has_attached_file :cover, :storage => s3, :s3_credentials => { :access_key_id => ENV['S3_KEY'], :secret_access_key => ENV['S3_SECRET'] }, :bucket => 'comicsapp', :url => ":s3_path_url", :s3_headers => { 'Expires' => 1.year.from_now.httpdate }, :styles => { :thumb => "80x120>", :medium => "300x450>" } end
- 21. SERVER SERVER
- 22. STORAGE SERVER SERVER
- 23. the cloud can be EXPENSIVE
- 24. NODE NODE NODE NODE NODE NODE NODE NODE
- 25. CACHING NODE NODE NODE NODE NODE NODE NODE NODE
- 26. SERVER
- 27. CACHING SERVER
- 28. the cloud prefers SMALL APPS
- 29. NODE NODE NODE NODE NODE NODE NODE NODE
- 30. NODE NODE NODE NODE NODE NODE NODE NODE
- 31. REST
- 32. NODE NODE NODE EXTERNAL SERVICE NODE NODE NODE
- 34. SERVER
- 35. SERVER SERVER
- 36. SERVER SERVICE
- 38. CLOUD class Searcher cattr_accessor :index def self.index @api ||= IndexTank::Client.new(ENV['INDEXTANK_API_URL']) @index = @api.indexes 'articles' end def self.search(term) raw = self.index.search(term, :function => 1) results = raw['results'].to_a article_ids = results.map {|result| result['docid'] } unsorted = Article.published.where(:id => article_ids) results.map { |result| unsorted.find {|u| u.id.to_i == result['docid'].to_i} }.compact end end
- 39. EXPECT FAILURE
- 40. CLOUD class Searcher # ... def self.search(term) results = begin raw = self.index.search(term, :function => 1) raw['results'].to_a rescue URI::InvalidURIError # An IndexTank error occurred search_by_sql(term)['results'] end # ... end def self.search_by_sql(term) {'results' => Article.where(['content ILIKE ?', "%#{term}%"]). map {|a| {'docid' => a.id}}} end end
- 41. DEFENSIVE CODING
- 42. the cloud is ALWAYS CURRENT
- 43. RAISE YOUR HAND if
- 44. INFRASTRUCTURE
- 46. HUMILITY
- 47. LAZINESS
- 48. PARANOIA
- 49. SOLID single responsibility principle liskov substitution principle interface segregation principle
- 51. THANK YOU! Ben Scofield / @bscofield http://benscofield.com http://speakerrate.com/t/7123