In a new post on the SitePoint PHP blog today, Harry Fuecks has created a "wide finder" based on a project put together by Tim Bray.
Tim set a simple, but very much real-world challenge; write an app that determines the top 10 most popular blogs from his Apache access log. It should be fast and readable, with a subtext of illustrating how "language X" copes in terms of parallel processing and utilizing "wider" (many processor) systems.
Since PHP natively doesn't support multi-threading (well), Harry opted to go with an approach using curl_multi_exec instead. There's two pieces to the puzzle - the mapper to grab the information and extract the data and the reducer that makes the calls to grab the information from the log files.