Peer-to-Peer networks are designed to provide decentralized, fault-tolerant alternatives to traditional client-server architectures. In previous work, the the resilience of structured P2P networks has been evaluated analytically as well as by simulation. In this paper, we discuss the influence of peer failures on a core component of our cost-optimized hierarchical P2P protocol Chordella. We show that the used algorithms lead to a working system even if a high number of superpeers is subject to failures.