With the growing popularity of information retrieval (IR) in distributed systems and in particular P2P Web search, a huge number of protocols and prototypes have been introduced in the literature. However, nearly every paper considers a different benchmark for its experimental evaluation, rendering their mutual comparison and the quantification of performance improvements an impossible task. We present a standardized, general purpose benchmark for P2P IR systems that finally makes this possible. We start by presenting a detailed requirement analysis for such a standardized benchmark framework that allows for reproducible and comparable experimental setups without sacrificing flexibility to suit different system models. We further suggest Wikipedia as a publicly-available and all-purpose document corpus and finally introduce a simple but yet flexible clustering strategy that assigns the Wikipedia articles as documents to an arbitrary number of peers. After proposing a standardi...