sinatra + mysql2でNewRelicのDB分析を有効にする

app.rb

require 'sinatra'
require 'newrelic_rpm'
require 'mysql2'
require 'mysql2-cs-bind'

class Mysql2ClientWithNewRelic < Mysql2::Client
  def initialize(*args)
    super
  end

  def query(sql, *args)
    callback = -> (result, metrics, elapsed) do
      NewRelic::Agent::Datastores.notice_sql(sql, metrics, elapsed)
    end
    op = sql[/^(SELECT|INSERT|UPDATE|DELETE|BEGIN|COMMIT|ROLLBACK)/i] || 'other'

    table = sql[/\bchair|estate\b/] || 'other'
    NewRelic::Agent::Datastores.wrap('MySQL', op, table, callback) do
      super
    end
  end
end

class App < Sinatra::Base
  helpers do
    def db_info
      {
        host: ENV.fetch('MYSQL_HOST', '127.0.0.1'),
        port: ENV.fetch('MYSQL_PORT', '3306'),
        username: ENV.fetch('MYSQL_USER', 'isucon'),
        password: ENV.fetch('MYSQL_PASS', 'isucon'),
        database: ENV.fetch('MYSQL_DBNAME', 'isuumo'),
      }
    end
    
    def db
      Thread.current[:db] ||= Mysql2ClientWithNewRelic.new(
        host: db_info[:host],
        port: db_info[:port],
        username: db_info[:username],
        password: db_info[:password],
        database: db_info[:database],
        reconnect: true,
        symbolize_keys: true,
      )
    end
  end
end