Online track reconstruction for HERA-B

The reconstruction of beauty hadrons in pN interactions, generated by suspending a wire target in the halo of the HERA proton beam, will have to be performed online, in tune with the HERA-B data acquistion. The challenges imposed by the huge track density and data rate, the solutions which have been developed, their performance tested on simulated data and a concept for a scalable processor farm are presented.