Hi Bart, I think you might be interested in the (admittedly short) section of the doc about RichFunctions: https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/api_concepts.html#rich-functions <https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/api_concepts.html#rich-functions>
If you make your user function a RichFunction you can implement the lifecycle methods open() and close() that allow you to setup, for example, a database connection that you wan't to reuse for the lifetime of your user function. Best, Aljoscha > On 24. Aug 2017, at 17:42, Stefan Richter <s.rich...@data-artisans.com> wrote: > > Hi, > > the lifecycle is described here: > https://ci.apache.org/projects/flink/flink-docs-release-1.3/internals/task_lifecycle.html > > <https://ci.apache.org/projects/flink/flink-docs-release-1.3/internals/task_lifecycle.html> > > Best, > Stefan > >> Am 24.08.2017 um 14:12 schrieb Bart Kastermans <fl...@kasterma.net >> <mailto:fl...@kasterma.net>>: >> >> I am using the scala api for Flink, and am trying to set up a JDBC >> database connection >> in my job (on every incoming event I want to query the database to get >> some data >> to enrich the event). Because of the serialization and deserialization >> of the code as >> it is send from the flink master to the flink workers I cannot just open >> the connection >> in my main method. Can someone give me a pointer to the lifecycle >> methods that >> are called by the worker to do local initialization of the job? I have >> not yet been able >> to find any references or examples of this in the documentation. >> >> Thanks! >> >> Best, >> Bart >
