HoustonPutman commented on PR #1650: URL: https://github.com/apache/solr/pull/1650#issuecomment-1582635343
So this should be ready to start reviewing. It still needs testing and docs, but I don't want to do that until the design has a +1 from others. This PR now shifts the existing PlacementPlugins to be subclasses of OrderedNodePlacementPlugin, which gives default implementations of `computePlacements()` and `computeBalancing()`. These subclasses merely need to implement a `getWeightedNodes()` method, which returns a mapping from `Node` to `WeightedNode`. Each plugin makes its own implementation of `WeightedNode`, because the "weighting" is determined by what that plugin wants to prioritize when making selections. The `WeightedNode` abstract class has become a bit bloated, but basically it allows a Node to keep track of a state, and make an overall "weight" for that node with the given state. (It also has a method to project relevant weight with a given replica added, that's what used for `computePlacements()`). I'm sure I need to do a lot more explanation, but in general, the given plugins should work almost exactly as they do today, with the added benefit of having `computeBalancing()` come for "free". (though I'm sure the implementation of that shared method can be improved with time) This OrderedNodePlacementPlugin is just a class that the existing PlacementPlugins extend, so it is back-compat with custom plugins. We should mark the class expirimental for 9.x, so that we can make improvements to OrderedNodePlacementPlugin without having to worry about back-compat guarantees while we are improving these APIs. (e.g., the WeightedNode class may need additional methods if we want to make improvements to the sorting). I'm also happy to split the `OrderedNodePlacementPlugin` changes into its own PR, so that it can be reviewed independently of the BalanceReplica code. Let me know what you think! -- 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-unsubscr...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org
