clintropolis commented on a change in pull request #8173: Add a cluster-wide configuration to force timeChunk lock and add a doc for segment locking URL: https://github.com/apache/incubator-druid/pull/8173#discussion_r308906002
########## File path: docs/content/ingestion/locking-and-priority.md ########## @@ -24,30 +24,73 @@ title: "Task Locking & Priority" # Task Locking & Priority +This document explains the task locking system in Druid. Druid's locking system +and versioning system are tighly coupled with each other to guarantee the correctness of ingested data. + +## Overshadow Relation between Segments + +You can run a task to overwrite existing data. The segments created by an overwriting task _overshadows_ existing segments. +Note that the overshadow relation holds only for the same time chunk and the same data source. +These overshadowed segments are not considered in query processing to filter out stale data. Review comment: It might be worth adding a sentence somewhere in here defining that all segments have a major and minor version, since they are mentioned in the example immediately after. This I think would help associate this concept to the later sections that map major versions to time chunk locking and minor versions to segment locking. ---------------------------------------------------------------- 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] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
