kfaraz commented on PR #18082:
URL: https://github.com/apache/druid/pull/18082#issuecomment-2969293910

   Thanks for bringing this up, @maytasm !
   We could have kept the column around but I felt like it would only add to 
the confusion,
   since the metadata in that table is relevant only for a supervisor and not 
for the datasource itself.
   
   But thinking on this some more, I think rolling upgrade itself would be a 
problem with the rename strategy.
   Say a new Overlord comes up and renames the column, while an Overlord which 
is still leader is
   trying to access the old column.
   
   So, I think we SHOULD NOT rename the column. cc: @jtuglu-netflix 
   We will have to live with the slight mess in the code that is needed to 
handle both datasource and supervisor_id
   together. The dataSource column will essentially be a dummy column after 
this patch anyway.
   
   I wonder if we would have a similar problem with the proposed change in this 
patch.
   A leader Overlord which is still on old version would insert new records 
with supervisor_id = null (or default empty),
   while the new Overlord is still adding the primary key on `supervisor_id`.
   This would create trouble when adding a UNIQUE or PRIMARY KEY on 
`supervisor_id`.


-- 
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