ndimiduk commented on pull request #4014: URL: https://github.com/apache/hbase/pull/4014#issuecomment-1006902804
reviewers: please notice this change to internal behavior of caching region locations in `HRegionLocator#listRegionLocations()`. I believe that the contents of the cache are identical before and after this change, but how the cache is populated is slightly different now. Previously, this method returned a `List<RegionLocations>`. In that implementation, each entry in the list represented a `Result` object processed by the `Visitor`. These entries were then presented to the connection for caching one-by-one. The logic used to merge old and new cache entries was also used to merge all of these new results. I think the one-to-one mapping is an unnecessary preservation of arbitrary physical topology of the scan of the meta region. The change here has `listRegionLocations()` perform this consolidation before returning results. Performing the `consolidate` action here allows the `HRegionLocator` to behave in a manner that is similar to `AsyncRegionLocator` and even reuse some of its code. This new implementation may also make region caching slightly (negligibly) faster because the logic for cache entry management is quite complex, while the logic for naively combining multiple `RegionLocations` objects into a single instance is much simpler. -- 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...@hbase.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
