+1 for setup() and teardown() methods. Very usual for proper initialization and cleanup of DoFn related data structures.
On Wed, Jun 29, 2016 at 9:34 PM, Aljoscha Krettek <[email protected]> wrote: > +1 I think some people might already mistake the > startBundle()/finishBundle() methods for what the new methods are supposed > to be > > On Tue, 28 Jun 2016 at 19:38 Raghu Angadi <[email protected]> > wrote: > > > This is terrific! > > Thanks for the proposal. > > > > On Tue, Jun 28, 2016 at 9:06 AM, Thomas Groh <[email protected]> > > wrote: > > > > > Hey Everyone: > > > > > > We've recently started to be permitted to reuse DoFn instances in > > Beam[1]. > > > Beyond the efficiency gains from not having to deserialize new DoFn > > > instances for every bundle, DoFn reuse also provides the ability to > > > minimize expensive setup work done per-bundle, which hasn't formerly > been > > > possible. Additionally, it has also enabled more failure cases, where > > > element-based state leaks improperly across bundles. > > > > > > I've written a document proposing that two methods are added to the API > > of > > > DoFn, setup and teardown, which both provides hooks for users to write > > > efficient DoFns, as well as signals that DoFns will be reused. > > > > > > The document is located at > > > > > > > > > https://docs.google.com/document/d/1LLQqggSePURt3XavKBGV7SZJYQ4NW8yCu63lBchzMRk/edit?ts=5771458f# > > > and committers have edit access > > > > > > Thanks, > > > > > > Thomas > > > > > > [1] https://github.com/apache/incubator-beam/pull/419 > > > > > >
