FYI https://issues.apache.org/jira/browse/TEZ-668
This adds a start method to the Input/Output and the processor is expected to call input.start()/output.start() for the input/output to actually start fetching/writing data. After this get committed, processors need to call start() on the input/output that they want to start. The processors may decide to not call start for an input they do not want to read (e.g. data already in ObjectRegistry) or they may choose to stagger the inputs in a certain order based on memory or processing requirements. -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
