  The trigger systems of the LHC detectors play a crucial role in determining
the physics capabilities of the experiments. A reduction of several orders of
magnitude of the event rate is needed to reach values compatible with the
detector readout, offline storage and analysis capabilities. The CMS experiment
has been designed with a two-level trigger system: the Level 1 (L1) Trigger,
implemented on custom-designed electronics, and the High Level Trigger (HLT), a
streamlined version of the CMS reconstruction and analysis software running on
a computer farm. The software-base HLT requires a trade-off between the
complexity of the algorithms, the sustainable output rate, and the selection
efficiency. This is going to be even more challenging during Run II, with a
higher centre-of-mass energy, a higher instantaneous luminosity and pileup, and
the impact of out-of-time pileup due to the 25 ns bunch spacing. The online
algorithms need to be optimised for such a complex environment in order to keep
the output rate under control without impacting the physics efficiency of the
online selection. Tracking, for instance, will play an even more important role
in the event reconstruction. In this poster we will present the performance of
the online track and vertex reconstruction algorithms, and their impact on the
hadronic triggers that make use of b-tagging and of jets reconstructed with the
Particle Flow technique. We will show the impact of these triggers on physics
performance of the experiment, and the latest plans for improvements in view of
the Run II data taking in 2015.
