dpcollins-google commented on pull request #14294: URL: https://github.com/apache/beam/pull/14294#issuecomment-804889499
> We would expect that when a consumer of a subscription, with ordering enabled, would receive the outputted messages (with the same ordering key) in the order they were published. This will likely not be achieved by this PR. The beam model does not preserve ordering within a PCollection, allowing elements to be reordered arbitrarily. > The order in which these messages are published is as far as I know determined by the timestamp of each element. I do not believe a Beam runner is required to process windows in timestamp order: if processing of a given window stalls, another window can begin to proceed concurrently. In this case, it would result in disordered messages between windows. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
