We are continuing our efforts in contributing our OpenDremel code to Apache Drill project and look forward to be active with it right after that.
Right now the efforts are being put into our ANTLR-based parser, we want to make it work with the new grammar of BigQuery language. That should be done within a few days, the parser will be committed to the new Drill repository as a first phase of the OpenDremel-Drill merge.
Next on, we plan to refactor and contribute the Semantic Analyzer, which processes the output of the parser into an intermediate form, resolving references and rewriting (flattening) the query into single full table scan operation. That is expected within a week or two, it would depend when the Drill architecture doc will be published. We still don’t know what will be the schema language/format. Will it be Protobuf? Avro? OpenDremel supports Avro right now and has an initial support for Protobuf.
The final phase of OpenDremel – Drill merge, will be the contribution of the code generator based on the Apache Velocity templates. We have two sets of templates for now: one is a Java-based and executed with Janino executor and second one uses C/asm and executed with ZeroVM executor.
Everyone who wishes to help is welcome. The OpenDremel code resides in its usual Google code repo – http://code.google.com/p/dremel/. BE SURE TO LOCATE AND USE REPO COMBO BOX on the upper part of the page.
We probably will use https://github.com/ApacheDrill repo as a staging area or the Apache git repo directly, it all depends on what will be proposed by Ted Dunning – the Apache Drill Champion.
We also continue work on our generic execution backend built on top of OpenStack Swift and integrated with ZeroVM. We are contributing to both projects here.
We look ahead to Apache Drill with pluggable frontends and pluggable backends. So it would be able to run on top of a toy single-JVM Janino backend, or under YARN management on HDFS with Janino or ZeroVM backend, or even on a Zwift backend (that’s how we codenamed OpenStack Swift + ZeroVM combo).
On other hand the frontends will be pluggable too, so, in the future, support for new languages such as Apache Pig or Apache Hive can be added easily. Another option would be to create single frontend with pluggable language handlers, that would allow us to embed functionality from other projects such as Apache Mahout or R.