sodonnel commented on PR #6385: URL: https://github.com/apache/ozone/pull/6385#issuecomment-2010740213
The generationID in google cloud appears to be like the version in AWS and in Ozone to some extent (I believe versioning is not fully implemented in Ozone). From the docs: > There is no guarantee that generation numbers increase for successive versions, only that each new version has a unique generation number. > There is no relationship between the generation numbers of unrelated objects, even if the objects are in the same bucket. From that, it is not clear if each generationID is unique across the bucket, or if two different keys can have the the same generationID. In Ozone, if you create a key, with objectID=5, and then create a new key of the same name, the objectID, I believe, remains the same, but the update_id is incremented. If you deleted the key (without versioning enabled) and recreated it, the object_ID will change. UpdateID comes from the Ratis Transaction ID (if Ratis is enabled), so it is probably unique on its own without the objectID, but I am not sure if that can be trusted without Ratis enabled. Also based on comments in WithObjectID.java. Therefore I think that to guarantee an object has not changed, we need both object and update ID. For now, I don't think we should expose any of this via the S3 or Hadoop compatible filesystems. We could also tag the new bucket.overwriteKey() as experimental for now, giving us scope to remove it or change it later if we decide it is not useful. However I still think it could be adapted to a new approach easily behind the public interface. Basically, I think the whole Ozone version story and version ID along with object and update ID needs to be fully worked out before we expose anything more widely that is done in this PR. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
