[GitHub] [helix] jiajunwang commented on issue #586: Improve the WAGED rebalancer performance.

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

jiajunwang commented on issue #586: Improve the WAGED rebalancer performance.
URL: https://github.com/apache/helix/pull/586#issuecomment-553585032
 
 
   > The fact of time complexity doesn't change: O(# of replicas * # nodes) and we're assigning each replica one by one. However, it may not be true (2 replicas assigned to 2 different nodes don't conflict with each other and change the cluster context). The time complexity can be improved to
   > O( # of replicas / avg batch assign size * # nodes)
   > 
   > Another idea to boost the performance:
   > 
   > ```
   > while unassignedReplicas > 0:
   >     # parallel
   >     list of [node, replica] proposed assginments =  parallelComputeSoftConstraints(nodes, unassignedReplicas) 
   >    list of [node, replica] unconfliced assignments = filter(proposed assignments)
   >    applu(unconfliced assignments)
   > ```
   
   I tied. But to my surprise, the time spent was not reduced obviously. It would be a little bit faster, but the logic would be much more complicated. So I think better to postpone this change since the other plan will have a larger return.
   For this PR, I don't want to change the logic.
   I will have another PR for the improvement that does change the logic.

----------------------------------------------------------------
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:
users@infra.apache.org


With regards,
Apache Git Services

---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@helix.apache.org
For additional commands, e-mail: reviews-help@helix.apache.org