Competitious on Rails

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Competitious on Rails

• Kris Rasmussen, Andrew Holt

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Competitious on Rails

• Who we are
• What is Competitious
• Why Ruby on Rails?
• Pros/Cons
• Competitious code

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Andrews Background

• B.S. in Computer Science from Stanford
• Engineer and project manager at Yahoo!
• Co-founded Revunity
• Interim creations
• Co-founded RivalSoft (Competitious)

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Kris Background

• Web and mobile 3D graphics engines
• CS and Math from UCLA
• Internet design and engineering consultant
• Software Engineer at Microsoft
• Sharepoint -gt worked on blogs, scripting
  security, wikis, UI, and extensibility of the
  platform
• Started PersonalTrainerPages.com, built on top of
  a scalable, drag and drop AJAX based vertical
  content management platform
• Started Competitious

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Competitious

• Online service that enables companies to better
  discover, organize, and analyze data on
  competition
• Initial beta release in October, 2006
• Plan to change the way companies consume and act
  on competitive information

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Considering Web Technologies

• Development speed
• Libraries Frameworks
• Scalability
• Maintainability
• MVC
• Components, Templating
• Code readability
• Code size

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Why we chose Ruby on Rails

• Less configuration and plumbing code required
• No template languages
• Easier to test, and iteratively develop
• Less emphasis on broad packaged components
• Elegant and familiar syntax
• Non-bloated JS libraries and slick AJAX

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It worked!

• We built the first version of Competitious in 3
  weeks!
• Partials and Helpers enabled common functionality
  to be shared much more easily than component
  based frameworks
• We have been able to constantly evolve the
  service and the database and respond quickly to
  customer feedback

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But there are problems...

• Refactoring code is difficult
• Single threaded/memory heavy processes
• Needs some work to get production mode really
  ready for production
• Does not support some complex queries
• Fetches all the data, all the time
• Easy to over-query the database

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Production Checklist

• Automatic deployment SVN Capistrano Mongrel
• Filter sensitive data out of logs
• filter_parameter_logging password
• Store sessions in memory or in the database
• Clear them when they expire
• Keep database round trips to a minimum, cache
  when necessary
• Ensure your Web Server is serving static files!
• Security reviews cross site scripting, sql
  injection, and permissions on objects when
  referencing by id
• Dont rely on with_scope!

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Glimpse into Competitious

• Not fully RESTful yet
• Lots of Many to many relationships, dont limit
  yourself unless performance really is an issue
• Acts as everything
• Acts_as_noteable
• Acts_as_loggable (more on this later)
• Acts_as_securable
• Acts_as_taggable
• Acts_as_mediable
• 19 controllers, 18 models

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Biggest Performance Issue

• Waiting on other services
• When other services go down or respond slowly
  your service shouldnt
• Why is this a problem
• You cant run many rails processes at once
  (memory)
• You cant count on 3rd parties

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Step 1 Caching

• Reduce number of times you have to wait.
• Simple time based ObjectCache
• data ObjectCache.cache(key,CACHE_TIME) do
  request_3rd_party_data(key)end
• Reduces average wait time but users will still
  encounter worst wait time for ever.
• Not all TOS allow you to cache

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Step 2 Timeouts

• Ensure your rails processes are available!
• status Timeouttimeout(3) do
  NetHTTP.get(url)
• end
• When all else fails fall back on cached data
• Problem user still has to wait for longer than
  they should when other data might be ready

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Step 3 Asynchronous Polling

• Start up new processes/threads to communicate
  with the third party service at the beginning of
  the request
• Use lighter weight processes for this
  (backgroundDRb)
• If by the end of the request the data is
  available, then display it
• If not then use AJAX to poll the server after
  the page is rendered

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Making AJAX more responsive

• Dont hit the server unless absolutely necessary
• Common when doing in place editing
• You dont have to duplicate view logic in
  Javascript using ugly inner HTML or the DOM.

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Javascript Templates

• Write a simple js template engine
• Example Template
• lt define_js_template("new_feature_tmpl") do
  gt lttr id"new-feature-row-(id)"
  class"new-feature-row"gt lt end gt
• render_js_template(new_feature_tmpl",'id'id,'ty
  pe'type,'type_name'type_name)

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How does it work?

• Rails Generated html is embedded inside hidden
  textareas
• Client Javascript loads template and replaces
  variables with current parameters
• Advantages All view code in one place, less
  server round trips, dont need to write much
  Javascript
• See our Comparison Matrix for an example

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Activity Logging

• Problems associated with activity logging
• Records may be created/updated/destroy etc in
  multiple places
• Each record has different data that should be
  displayed in the log
• After records are updated/deleted log entries and
  references need to be updated

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acts_as_loggable !

• Model
• acts_as_loggable name
• Controller
• Media.with_logging(user gt_at_current_user) .
• Use in an around_filter
• Views
• Create partials for rendering log for each
  loggable type

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Models

• class LogEntry lt ActiveRecordBase
• belongs_to log_object
• belongs_to user
• end
• class LogObject lt ActiveRecordBase
• belongs_to loggable, polymorphic gt true
• has_many log_entries, dependentgtdestroy
• end

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Advanced Usage

• acts_as_loggable name,mediable_type,mediable_i
  d,mediablegtname
• Media.with_logging(actiongt'published') do
• _at_media.update_attribute('published',true)
• End
• Media.with_logging(datagtextradata)
• Acts_as_loggable record,extradata return
  hash_of_data

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Plugin will be posted on our blog

• http//blog.competitio.us

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Contact Us

• Kris
• kris_at_competitio.us
• Andrew
• andrew_at_competitio.us