Open method is called just before any elements are processed. You can hook in any initialisation logic there, including initialisation of a static context. However keep in mind, that since this context is static, it will be shared between multiple operators (if you are running parallelism > number of task managers), so accesses to it must be synchronized (including initialisation). Another thing to consider is that managing the life cycle of static context can be tricky (when to close it and release it’s resources).
The questions is, whether you really need a static context? Thanks, Piotrek > On 21 Dec 2017, at 07:53, Steven Wu <stevenz...@gmail.com> wrote: > > Here is my understanding of how job submission works in Flink. When > submitting a job to job manager via REST API, we provide a entry class. Job > manager then evaluate job graph and ship serialized operators to task > manager. Task manager then open operators and run tasks. > > My app would typically requires some initialization phase to setup my own > running context in task manager (e.g. calling a static method of some class). > Does Flink provide any entry hook in task manager when executing a job (and > tasks)? As for job manager, the entry class provides such hook where I can > initialize my static context. > > Thanks, > Steven
