Search engines represent a key component of Web economy these days. Despite that, there is not much technical literature available on their design, fine tuning, and internal operation. In this work, we make a preliminary attempt to partially fulfill this gap. We distinguish that Web query processing is composed of two phases: (a) retrieving information on documents related to the queries and ranking them, and (b) generating snippets, title, and URL information for the answer page. The second phase has cost that is basically constant on the size of the collection, while the cost of the first phase is affected by the size of the collection. Thus, we concentrate here on studying the behavior of a search engine while executing the first phase of query processing. Using real data and a small cluster of index servers, we study four basic and key issues related to this first phase of query processing: load balance, broker behavior, performance by individual index servers, and overall t...
Claudine Santos Badue, Ramurti A. Barbosa, Paulo B