discourse/config/initializers/logster.rb

if Rails.env.production?
  Logster.store.ignore = [
    # honestly, Rails should not be logging this, its real noisy
    /^ActionController::RoutingError \(No route matches/,

    /^PG::Error: ERROR:\s+duplicate key/,

    /^ActionController::UnknownFormat/,

    # super annoying empty JS errors in the form of
    #
    # Script error.
    # Url:
    # Line: 0
    # Column: 0
    # Window Location: http://discourse.codinghorror.com/t/the-god-login/2924/19
    #
    /^Script error.\nUrl: \nLine: 0?\n/,

    # suppress trackback spam bots
    Logster::IgnorePattern.new("Can't verify CSRF token authenticity", { REQUEST_URI: /\/trackback\/$/ }),

    # API calls, TODO fix this in rails
    Logster::IgnorePattern.new("Can't verify CSRF token authenticity", { REQUEST_URI: /api_key/ })
  ]
end

# middleware that logs errors sits before multisite
# we need to establish a connection so redis connection is good
# and db connection is good
Logster.config.current_context = lambda{|env,&blk|
  begin
    if Rails.configuration.multisite
      request = Rack::Request.new(env)
      ActiveRecord::Base.connection_handler.clear_active_connections!
      RailsMultisite::ConnectionManagement.establish_connection(:host => request['__ws'] || request.host)
    end
    blk.call
  ensure
    ActiveRecord::Base.connection_handler.clear_active_connections!
  end
}