The first part can be found in http://blog-bhaskaruni.blogspot.in/2012/11/google-search-architecture.html.
We have seen some components MapReduce, GFS (Google File System) API/software abstractions.
Google published the architecture. And based on this major software firms "Facebook" and others use the same architecture.
1. Hadoop and its "Hadoop Distributed File System" (HDFS), an open source Java product similar to GFS.
2. Hadoop is open source implementation of the GFS
Besides Facebook and Yahoo!, many other organizations are using Hadoop to run large distributed computations.