List of features and known issues that are marked for future Terrier versions:
CompressionFactory/CompressionConfig is not supported by single-pass or Hadoop indexing.
Query language should be refined: In particular, ambiguity warnings when generating the parser with ANTLR should be removed, and a more structured query language should be introduced. We plan to use a subset of the Indril query language internally from version 5.0.
The real-time index structures do not currently support block indexing
The following classes and interfaces are/may be deprecated in this version of Terrier and will likely be removed or refactored in a future release:
structures.BlockLexiconEntry & structures.BlockFieldLexiconEntry will be removed in a future version of Terrier.
structures.bit.DirectIndex and structures.bit.InvertedIndex will be removed in a future version of Terrier.
ApplicationSetup will be replaced with a new non-global configuration API.
Terrier currently uses Hadoop version 0.20. Future releases of Terrier will upgrade to a later branch. Instructions to upgrade Terrier yourself can be found here
All community contributions to the Terrier framework are welcome. In addition, you can find more information about contributing on the Terrier website.