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ASF GitHub Bot logged work on HIVE-25277: ----------------------------------------- Author: ASF GitHub Bot Created on: 03/Sep/21 18:39 Start Date: 03/Sep/21 18:39 Worklog Time Spent: 10m Work Description: coufon commented on a change in pull request #2421: URL: https://github.com/apache/hive/pull/2421#discussion_r702097544 ########## File path: standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HMSHandler.java ########## @@ -5240,16 +5259,38 @@ public DropPartitionsResult drop_partitions_req( for (Path path : archToDelete) { wh.deleteDir(path, true, mustPurge, needsCm); } + + // Uses a priority queue to delete the parents of deleted directories if empty. + // The parent with the largest size is always processed first. It guarantees that + // the emptiness of a parent won't be changed once it has been processed. So duplicated + // processing can be avoided. + PriorityQueue<PathAndPartValSize> parentsToDelete = new PriorityQueue<>(); for (PathAndPartValSize p : dirsToDelete) { wh.deleteDir(p.path, true, mustPurge, needsCm); + addParentForDel(parentsToDelete, p); + } + + HashSet<PathAndPartValSize> processed = new HashSet<>(); + while (!parentsToDelete.isEmpty()) { try { - deleteParentRecursive(p.path.getParent(), p.partValSize - 1, mustPurge, needsCm); + PathAndPartValSize p = parentsToDelete.poll(); + if (processed.contains(p)) { + continue; + } + processed.add(p); + + Path path = p.path; + if (wh.isWritable(path) && wh.isDir(path) && wh.isEmptyDir(path)) { Review comment: wh.isEmptyDir uses listStatus that doesn't distinguish file and dir (at least for the GCS fs implementation: https://github.com/GoogleCloudDataproc/hadoop-connectors/blob/7825ab50c839aea43f1ff587b0e2803047af99bc/gcsio/src/main/java/com/google/cloud/hadoop/gcsio/GoogleCloudStorageFileSystem.java#L997). But I agree that isEmptyDir is enough no matter the path is a file or dir. -- 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: gitbox-unsubscr...@hive.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org Issue Time Tracking ------------------- Worklog Id: (was: 646433) Time Spent: 3.5h (was: 3h 20m) > Slow Hive partition deletion for Cloud object stores with expensive ListFiles > ----------------------------------------------------------------------------- > > Key: HIVE-25277 > URL: https://issues.apache.org/jira/browse/HIVE-25277 > Project: Hive > Issue Type: Improvement > Components: Standalone Metastore > Affects Versions: All Versions > Reporter: Zhou Fang > Assignee: Zhou Fang > Priority: Major > Labels: pull-request-available > Time Spent: 3.5h > Remaining Estimate: 0h > > Deleting a Hive partition is slow when use a Cloud object store as the > warehouse for which ListFiles is expensive. A root cause is that the > recursive parent dir deletion is very inefficient: there are many duplicated > calls to isEmpty (ListFiles is called at the end). This fix sorts the parents > to delete according to the path size, and always processes the longest one > (e.g., a/b/c is always before a/b). As a result, each parent path is only > needed to be checked once. -- This message was sent by Atlassian Jira (v8.3.4#803005)