![stale?(etag:
x)
-‐>
Etag:
md5(expand_cache_key(x))
# File activesupport/lib/active_support/cache.rb, line 77
def expand_cache_key(key, namespace = nil)
expanded_cache_key = namespace ? "#{namespace}/" : ""
if prefix = ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
expanded_cache_key << "#{prefix}/"
end
expanded_cache_key << retrieve_cache_key(key)
expanded_cache_key
end
# File activesupport/lib/active_support/cache.rb, line 90
def retrieve_cache_key(key)
case
when key.respond_to?(:cache_key) then key.cache_key
when key.is_a?(Array) then key.map { |element|
retrieve_cache_key(element)
}.to_param
else
end.to_s
end
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-10-320.jpg)
![# File activerecord/lib/active_record/integration.rb, line 37
def cache_key
case
when new_record?
"#{self.class.model_name.cache_key}/new"
when timestamp = self[:updated_at]
timestamp = timestamp.utc.to_s(:number)
"#{self.class.model_name.cache_key}/#{id}-#{timestamp}"
else
"#{self.class.model_name.cache_key}/#{id}"
end
end
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-11-320.jpg)
![EN RAILS
•SIN ETAGGER
stale?(etag:
[current_user,
@modelo])
stale?(etag:
[current_user,
@otro])
stale?(etag:
[current_user,
@otromas])
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-12-320.jpg)
![EN RAILS
•EN AC PERFORACIONES
etag
{
[current_user,
ENV[‘COMMIT_HASH’]
}
stale?(etag:
modelo)
stale?(etag:
otro)
stale?(etag:
otromas)
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-14-320.jpg)
![Rails Fragment
Caching
-‐cache
‘foo’
do...end
-‐cache
modelo
do...end
-‐cache
[reporte,
‘inbox’]
do..end
# File actionpack/lib/action_controller/caching/fragments.rb, line 51
def fragment_cache_key(key)
ActiveSupport::Cache.expand_cache_key(
key.is_a?(Hash) ?
url_for(key).split("://").last :
key,
:views)
end
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-15-320.jpg)
![RUSSIAN DOLL
CACHING
-‐
cache
[reporte,
‘perforaciones’]
do
-‐
perforacion.each
do
|p|
-‐
cache
perforacion
do
%h1=
perforacion.titulo
%p=
perforacion.whatever
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-16-320.jpg)
![BONUS TRACK
def prefetch(url)
content_tag("script",
%Q{
$("<link href='#{escape_javascript(url)}'
rel='subresource'/>").appendTo('head')
}.html_safe
) unless current_page?(url)
end
def tab_detalle_reporte(text, opts = {})
collection = opts[:collection] || text.downcase.pluralize
url = send("reporte_#{collection}_path", estado, reporte)
tab_title(opts.merge!(
name: text,
href: url,
active: tab == collection
)) + prefetch(url)
end
Sunday, March 3, 13](https://image.slidesharecdn.com/cachingtips-130303181653-phpapp02/85/Caching-tips-20-320.jpg)
Caching tips
- 1. Caching tips Leo Soto M. Continuum Lecture & Beef, Marzo 2013 Sunday, March 3, 13
- 2. Caching tips (for webapps) Leo Soto M. Continuum Lecture & Beef, Marzoss 2013 Sunday, March 3, 13
- 3. “There are only two hard things in computer science... Sunday, March 3, 13
- 4. ...cache invalidation and naming things” - Phil Karlton Sunday, March 3, 13
- 5. HTTP Caching •Client-side! •...or “middle-side” (proxys!) •Conceptos claves: •Frescura (freshness) •Validacion/Invalidacion Sunday, March 3, 13
- 6. FRESH CACHES •HTTP/1.0: Expires: Fri, 01 March 2013 20:00:00 GMT •HTTP/1.1: Cache-‐Control: *pila-‐de-‐opciones* Cache-‐Control: private, max-‐age=3600 Sunday, March 3, 13
- 7. VALIDATED CACHES •HTTP/1.0: Last-‐Modified / If-‐Modified-‐Since 304 Not Modified •HTTP/1.1: ETag / If-‐None-‐Match 304 Not Modified Sunday, March 3, 13
- 8. CACHE INVALIDATION •METODOS HTTP QUE INVALIDAN CACHES FRESCAS: POST /resource DELETE /resource PUT /resource Sunday, March 3, 13
- 9. EN RAILS •FRESH CACHES: expires_in 1.hour •VALIDATED CACHES if stale?(etag: @modelo) otros_hits_a_la_bd end Sunday, March 3, 13
- 10. stale?(etag: x) -‐> Etag: md5(expand_cache_key(x)) # File activesupport/lib/active_support/cache.rb, line 77 def expand_cache_key(key, namespace = nil) expanded_cache_key = namespace ? "#{namespace}/" : "" if prefix = ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"] expanded_cache_key << "#{prefix}/" end expanded_cache_key << retrieve_cache_key(key) expanded_cache_key end # File activesupport/lib/active_support/cache.rb, line 90 def retrieve_cache_key(key) case when key.respond_to?(:cache_key) then key.cache_key when key.is_a?(Array) then key.map { |element| retrieve_cache_key(element) }.to_param else end.to_s end Sunday, March 3, 13
- 11. # File activerecord/lib/active_record/integration.rb, line 37 def cache_key case when new_record? "#{self.class.model_name.cache_key}/new" when timestamp = self[:updated_at] timestamp = timestamp.utc.to_s(:number) "#{self.class.model_name.cache_key}/#{id}-#{timestamp}" else "#{self.class.model_name.cache_key}/#{id}" end end Sunday, March 3, 13
- 12. EN RAILS •SIN ETAGGER stale?(etag: [current_user, @modelo]) stale?(etag: [current_user, @otro]) stale?(etag: [current_user, @otromas]) Sunday, March 3, 13
- 13. EN RAILS •CON ETAGGER etag { current_user } stale?(etag: modelo) stale?(etag: otro) stale?(etag: otromas) Sunday, March 3, 13
- 14. EN RAILS •EN AC PERFORACIONES etag { [current_user, ENV[‘COMMIT_HASH’] } stale?(etag: modelo) stale?(etag: otro) stale?(etag: otromas) Sunday, March 3, 13
- 15. Rails Fragment Caching -‐cache ‘foo’ do...end -‐cache modelo do...end -‐cache [reporte, ‘inbox’] do..end # File actionpack/lib/action_controller/caching/fragments.rb, line 51 def fragment_cache_key(key) ActiveSupport::Cache.expand_cache_key( key.is_a?(Hash) ? url_for(key).split("://").last : key, :views) end Sunday, March 3, 13
- 16. RUSSIAN DOLL CACHING -‐ cache [reporte, ‘perforaciones’] do -‐ perforacion.each do |p| -‐ cache perforacion do %h1= perforacion.titulo %p= perforacion.whatever Sunday, March 3, 13
- 17. TIPS FRAGMENT CACHING •Aplicar a cosas que no dependan del usuario actual •Usar cache_digests + memcached Sunday, March 3, 13
- 18. CONCLUSIONES •HTTP CACHING: •CACHE LOCAL AL USUARIO •AHORRA: •LATENCIA •ANCHO DE BANDA, •TIEMPO DE RESPUESTA DEL SERVIDOR Sunday, March 3, 13
- 19. CONCLUSIONES •FRAGMENT CACHING: •CACHE GLOBAL DE LA APP •AHORRA: •HITS A LA BD •CALCULOS •RENDERING Sunday, March 3, 13
- 20. BONUS TRACK def prefetch(url) content_tag("script", %Q{ $("<link href='#{escape_javascript(url)}' rel='subresource'/>").appendTo('head') }.html_safe ) unless current_page?(url) end def tab_detalle_reporte(text, opts = {}) collection = opts[:collection] || text.downcase.pluralize url = send("reporte_#{collection}_path", estado, reporte) tab_title(opts.merge!( name: text, href: url, active: tab == collection )) + prefetch(url) end Sunday, March 3, 13