I’ve decided to put some of the Hadoop code I developed for the TREC KBA task online. It’s available on Github: https://github.com/ejmeij/trec-kba. In particular, it provides classes to read/write topic files, read/write run files, and expose the documents in the Thrift files as Hadoop-readable objects (‘ThriftFileInputFormat’) to be used as input to mappers. I obviously also implemented a toy KBA system on Hadoop :-). See Github for more info.