[GitHub] [ozone] sodonnel commented on pull request #3667: HDDS-7092. EC Offline Recovery with simultaneous Over Replication

[GitBox <gi...@apache.org>]

sodonnel commented on PR #3667:
URL: https://github.com/apache/ozone/pull/3667#issuecomment-1222461718

   I'm not sure about this change. I feel it adds quite a bit of complexity to the model to handle what is really an edge case for a small cluster. I'd like a container to be handled for only a single state at a time as we could get into a position where we try reconstruction only to have a replica we are reading from removed by over-replication handling at the same time. It also makes things easier to think about, rather than the container having many states.
   
   Few thoughts come to mind:
   
   1. What if we return over-replication health first, before under-replication? That way, we can fix this with a small change, by just changing the order in the ECContainerHealthCheck. The negative is that we have to wait longer to fix an under-replication, but the change here will be small and the general flow stays the same.
   
   2. Or, inside the under-replication handler, we have access to the methods in ECContainerReplicaCount which can tell us if there are over-replicated indexes. If, and only if, we get a failure in the UnderRep handler due to not finding enough nodes, we can somehow switch to over-replication handling and remove the excess replicas. However that starts to muddle the over and under replication logic together, which I was trying to avoid.
   
   I probably need to think about it a bit more.


-- 
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: issues-unsubscribe@ozone.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@ozone.apache.org
For additional commands, e-mail: issues-help@ozone.apache.org