errose28 commented on PR #6385:
URL: https://github.com/apache/ozone/pull/6385#issuecomment-2013690253

   > 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.
   
   Object ID is derived from the Ratis transaction index of the create request. 
See [the 
method](https://github.com/apache/ozone/blob/4da5a642243a42bba1aea6701d3d6b4b3a9462b4/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManager.java#L2147)
 doing the calculation that is called from all create requests. Note the extra 
space created around each object ID to account for directories that might need 
to be created with a file create request. **Creating a new key with the same 
name will have a different object ID.**
   
   Update ID is also set on key create but additionally changed when metadata 
like Native ACLs are changed. This is just the Ratis transaction index with no 
additional modifications. See [this 
method](https://github.com/apache/ozone/blob/b537a6a710e83a413cfba87c02e0357c0365d114/hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/helpers/WithObjectID.java#L69)
 and everywhere it is used for what operations modify the update ID. I'm not 
sure what you mean "update ID is incremented". The update ID of the new key 
will be arbitrarily larger than the old key since it is a Ratis transaction 
index, but its value is not related to the update ID of the previous version of 
the key.


-- 
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]

Reply via email to