Ballista A modern distributed compute platform

Ballista 0.3.0-alpha-2

This is the second 0.3.0 alpha release and improves overall stability and UX.

This release contains the following improvements to the Rust project:

  • It is now possible to specify configuration options such as parquet and csv reader batch sizes when submitting queries.
  • Executors now use a simpler and more efficient worker thread model.
  • The scheduler is slightly more efficient and uses a stateful client when communicating with executors, reducing the overhead of creating new network connections.
  • The TPC-H example now accepts command-line arguments.
  • The HashAggregateExec operator is re-implemented using async/await, removing the overhead of a dedicated thread.
  • Explicit projections are now supported.
  • Improvements to Docker packaging.
  • Fixed bug where client-supplied schema was ignored.

This release contains the following improvements to the JVM project:

  • Serde code added for new protobuf messages involved in distributed query execution.

Known issues:

  • The scheduler is still extremely simple and inefficient.
  • Distributed query performance is not optimized yet.