Instrument ActiveRecord and push the results to Statsd

gistfile1.rb

SQL_PARSER_REGEXP = /^(\w+)\s(\w+)\s\W*(\w+)/

ActiveSupport::Notifications.subscribe "sql.active_record" do |name, start, finish, id, payload|
  if payload[:name] == "SQL"
    if Thread.current[:stats_context] # where I store the name of the request context
      payload[:sql] =~ SQL_PARSER_REGEXP  # $1 will be the query type, $3 the table
      Statsd.timing("#{Thread.current[:stats_context]}.sql.#{$3}.#{$1}.query_time",
                        (finish - start) * 1000, 1)
    end
  end
end

Note, by filtering on the payload "SQL" and using the provided regexp, you will only get part of the queries. I'll let you dig to find how to get the rest.

To be a bit more precise, in the AR version I'm using, the code above will only get you inserts and deletes. payload[:name] will be "ModelName Load" for some selects and updates and counts don't seem to set a payload name. You therefore need to write some basic parser code to capture inserts, selects, updates and deletes.