Tracking User Actions on Rails website

Users will each have a user profile, and he wants each user to know who has viewed their profile. The only way I can think of doing this involves doing a database INSERT every time someone views a profile page (probably using an Ajax call at the end of the page). This sounds like a massive performance issue, especially if the site builds up to any significant traffic.

Any ideas on how to achieve this in a开发者_JAVA百科 performant way, or is it just the nature of tracking this kind of thing?

Thanks.

1. Why add another ajax call to view?
   Do it When you call the user profile show action.. in the controller

2. Queue it to a background job (example: starling + workling)

3. Dont use acid DB for the viewed data, use some kind of key-value store db (cassandra, redis etc)

If you're using MySQL, I'm a big fan of using the "INSERT INTO...ON DUPLICATE KEY" feature which allows you to perform an update on a row if there's a key conflict. This means that instead of one row per profile view, there could be one row per user + profile pair, or for even more granularity, user + profile + day.

Depending on your traffic situation and choice of DB engine, this may work very well even for extended periods of time. Although there may be a very large number of rows in a tracking table like this, the content is very small, like a pair of ID fields and a numeric counter, which is on the order of 12-16 bytes per entry.

For example, a tracking table might be defined as:

def self.up
  create_table :user_profile_views do |t|
    t.integer :user_id
    t.integer :profile_user_id
    t.integer :count, :default => 0
  end

  add_index :user_profile_views, [ :user_id, :profile_user_id ], :unique => true
end

For the model:

def self.record_view_profile!(user, profile)
  connection.execute(sanitize_sql([ "
    INSERT INTO user_profile_views (user_id, user_profile_id, count)
      VALUES (%d,%d,1)
      ON DUPLICATE KEY UPDATE
       count=count+1
  ", user.id, profile.id ])
end

This will either insert a row, or update the count for an existing row.