ON PROTOBUFS This maven module has core protobuf definition files ('.protos') used by hbase REST. Generation of java files from protobuf .proto files included here is done apart from the build. Run the generation whenever you make changes to the .orotos files and then check in the produced java (The reasoning is that change is infrequent so why pay the price of generating files anew on each build. To generate java files from protos run: $ mvn compile -Dcompile-protobuf or $ mvn compile -Pcompile-protobuf After you've done the above, check it and then check in changes (or post a patch on a JIRA with your definition file changes and the generated files). Be careful to notice new files and files removed and do appropriate git rm/adds.