Ruby on Rails Application

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Ruby on Rails Application

• 11 Things to Consider Before Deploying Your Ruby
  on Rails Application

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Ruby on Rails

• At VinSol, we have been developing and deploying
  Rails applications for more than four years.
  During this period, we have identified some best
  practices that we prefer to follow while
  deploying rails application to production server.

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Below is the checklist of these practices

• 1. Ensure that NS records and MX records are
  changed if they need to be changed
• Changing nameservers will point the domain to the
  hosting server, and changing MX records will
  redirect incoming mails to the mail server. As a
  very first step, we should make sure that name
  servers of the domain are set to be the correct
  one. Changing MX record is a must if our
  application is parsing incoming mails or we wants
  to use other mail services for e-mail exchange,
  for example Gmail.

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2. Ensure some backup mechanism in place for both
data as well as user uploaded content like
images/documents etc.

• Since production data is very critical, we must
  setup backup mechanism. It could be some type of
  scheduled task that takes periodic backup of all
  critical data, Or it could be some type of backup
  service provided by hosting company. When we talk
  about critical production data, it includes
  production DB, content generated by application
  users like images, documents, etc.

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Ensure Database indexes

• We might have done development without having
  proper database indexes, but we should avoid
  going to production without them. Adding indexes
  might slow down insert queries a bit but it
  increases the performance of read queries. It
  applies when application in production has
  percentage of read operations much more than
  write operations.

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Enable your slow query log

• This is specific to MySQL. Enabling slow query
  log allows MySQL to log slow running queries to a
  file. And this log can be used to find queries
  that take a long time to execute and are
  therefore candidates for optimization.

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Ensure exception is in place

• We might want to be notified when something bad
  happens to our application. There are several
  hosted services available who receive and track
  exceptions, for example Hoptoadapp.com,
  GetExceptional.com etc Either we can choose one
  from these hosted services or we can use
  exception notifier plugin.

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Ensure adding entries for cron/scheduled jobs

• Most of the applications have some
  functionality/jobs that need to be run
  periodically, for example generating invoices,
  sending newsletters etc. In most cases these
  jobs are done by a rake task. We should make sure
  that we have added such jobs to cron or similar
  program.

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Monitoring Important Processes

• To ensure that our site is up 247 we need to
  ensure that all processes that our application
  needs are up. There can be many processes like
  MySQL, Mongrel, Apache etc.. These processes are
  very important as our application directly
  depends on them. For example if MySQL process get
  killed accidentally, our application would not be
  able to connect to MySQL and will start throwing
  exceptions. We can choose any of the available
  monitoring tools like God, Monit, 247 etc

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Ensure Confidential Data Filtering

• We would never like to leak/share confidential
  information of our application users. We should
  make sure that none of the users confidential
  data like SSN, Credit card info, password are
  being written to log files. We might not have
  paid much attention on this while developing the
  application.

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Rotate Log Files

• Once our site is up and running, every single
  request write some text in log file. And hence
  size of the log file keeps on increasing. Larger
  log files can put us in trouble if we get it
  beyond certain size. Its difficult to manage
  these log files, as larger files need more memory
  to open and need more time to download. In one of
  the rescue project we did , the log file size was
  3GB.
• We would recommend having logrotate setup for the
  application.

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Setup Asset Host

• Setting up asset hosts can reduce loading time by
  50 or more. We must setup asset hosts for our
  application. Once asset hosts are all set, our
  static files will be delivered via asset hosts
  for example asset1.hostname.com,
  asset2.hostname.com

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Clearing up stale sessions

• We should make sure we should not left any stale
  session on the server. If our application is
  using DB or file system as session store, we
  must add a schedule task to delete stale
  sessions.
• These are some of the points we have identified
  from our past experience and we might be missing
  some. Feel free to always add them as comments,
  and Ill keep this post updated.

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Thank you

• See more at - http//vinsol.com/blog/2009/11/16/11
  -things-to-consider-before-deploying-your-rails-ap
  plication/