  Online media offers opportunities to marketers to deliver brand messages to a
large audience. Advertising technology platforms enables the advertisers to
find the proper group of audiences and deliver ad impressions to them in real
time. The recent growth of the real time bidding has posed a significant
challenge on monitoring such a complicated system. With so many components we
need a reliable system that detects the possible changes in the system and
alerts the engineering team. In this paper we describe the mechanism that we
invented for recovering the representative metrics and detecting the change in
their behavior. We show that this mechanism is able to detect the possible
problems in time by describing some incident cases.
