nicusX commented on code in PR #28863: URL: https://github.com/apache/flink/pull/28863#discussion_r3913050453
########## docs/content/docs/concepts/glossary.md: ########## @@ -46,137 +48,331 @@ Cluster](#flink-cluster) is bound to the lifetime of the Flink Application. #### ApplicationResultStore The ApplicationResultStore is a Flink component that persists the results of terminated -(i.e. finished, cancelled or failed) applications to a filesystem, allowing the results to outlive -a terminated application. Each result contains the application's identifier, final state, name, -etc. These results are then used by Flink to determine whether applications should -be subject to recovery in highly-available clusters. +(i.e. finished, cancelled or failed) Applications to a filesystem, allowing the results to outlive +a terminated Application. Each result contains the Application's identifier, final state, name, +etc. These results are then used by Flink to determine whether Applications should +be subject to recovery in highly-available Clusters. + +#### Channel + +Also called *Stream Partitions*. + +A Channel is the physical link between a [Sub-Task](#sub-task) and a downstream Sub-Task, and the +edge of a [Physical Graph](#physical-graph). Parts of the documentation refer to Channels as *Stream +Partitions*, in the sense of internal, physical Partitions. + +Channels carry data records as well as signals such as [Watermarks](#watermark), Watermark Status +updates and Checkpoint barriers. Transmission over a Channel is always unidirectional (upstream to +downstream) and asynchronous. + +A Sub-Task may have one or more input Channels and one or more output Channels. Source Sub-Tasks have +no input Channels, since they begin the graph, and Sink Sub-Tasks have no output Channels, since they +end it. + +A Sub-Task routes each record to one of its output Channels according to the [Physical Review Comment: Routing is delegated to a ChannelSelector, which in turn depends on the partitioning. But this looks too detailed for a glossary TBH -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
