[jira] [Created] (HIVE-17802) Remove unnecessary calls to FileSystem.setOwner() from FileOutputCommitterContainer

["Mithun Radhakrishnan (JIRA)" <ji...@apache.org>]

Mithun Radhakrishnan created HIVE-17802:
-------------------------------------------

             Summary: Remove unnecessary calls to FileSystem.setOwner() from FileOutputCommitterContainer
                 Key: HIVE-17802
                 URL: https://issues.apache.org/jira/browse/HIVE-17802
             Project: Hive
          Issue Type: Bug
          Components: HCatalog
    Affects Versions: 2.2.0, 3.0.0
            Reporter: Mithun Radhakrishnan
            Assignee: Chris Drome


For large Pig/HCat queries that produce a large number of partitions/directories/files, we have seen cases where the HDFS NameNode groaned under the weight of {{FileSystem.setOwner()}} calls, originating from the commit-step. This was the result of the following code in FileOutputCommitterContainer:
{code:java}
private void applyGroupAndPerms(FileSystem fs, Path dir, FsPermission permission,
                  List<AclEntry> acls, String group, boolean recursive)
    throws IOException {
...
    if (recursive) {
      for (FileStatus fileStatus : fs.listStatus(dir)) {
        if (fileStatus.isDir()) {
          applyGroupAndPerms(fs, fileStatus.getPath(), permission, acls, group, true);
        } else {
          fs.setPermission(fileStatus.getPath(), permission);
          chown(fs, fileStatus.getPath(), group);
        }
      }
    }
  }

  private void chown(FileSystem fs, Path file, String group) throws IOException {
    try {
      fs.setOwner(file, null, group);
    } catch (AccessControlException ignore) {
      // Some users have wrong table group, ignore it.
      LOG.warn("Failed to change group of partition directories/files: " + file, ignore);
    }
  }
{code}

One call per file/directory is far too many. We have a patch that reduces the namenode pressure.



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