allGather(message: str = '') → List[str]¶
This function blocks until all tasks in the same stage have reached this routine. Each task passes in a message and returns with a list of all the messages passed in by each of those tasks.
New in version 3.0.0.
This API is experimental
In a barrier stage, each task much have the same number of barrier() calls, in all possible code branches. Otherwise, you may get the job hanging or a SparkException after timeout.