Events are meant to be a common object that can carry a payload between framework->user (InputFailedEvent), user->framework (InputReadErrorEvent), user->user (DataMovementEvent).
Events are routed based on event type and using internal metadata (source/destination metadata) present in the event. The metadata is automatically added by the system (eg. TezDAGChild adds source meta when the output produces an event). The main thing that users care about is the payload which is already serialized. The rest of the serde is taken care of by the system. This is by design so that the users don’t have to understand system internals and can use this easily. Their surface area of interaction is limited to sending/receiving the correct event/payload. The documentation per event can be improved to describe this better. Bikas -----Original Message----- From: Jianfeng (Jeff) Zhang [mailto:jzh...@hortonworks.com] Sent: Friday, June 27, 2014 12:28 AM To: dev@tez.incubator.apache.org Subject: Question on Event Hi all, I notice that class Event is used by both Input, Output, Processor and VertexManagerPlugin. But IMHO it's not clear for users on how to use them and user don't have full control on the events. Most of the logic is in tez-dag ( such as whether sending it to TezChild, it need, How to serialize/ deserialize these events ) It's hard to add customized events, although it may be a rare requirement . I am thinking that in the Event class, we should provide some methods that allow user to specify these attributes ( may need other code change ). My purpose is to help user understand how to use these event. What's your thinking on this ? Thanks Best Regards, Jeff Zhang -- 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. -- 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.
