hadoop-common-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Chris Nauroth (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HADOOP-13208) S3A listFiles(recursive=true) to do a bulk listObjects instead of walking the pseudo-tree of directories
Date Thu, 18 Aug 2016 04:42:22 GMT

     [ https://issues.apache.org/jira/browse/HADOOP-13208?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Chris Nauroth updated HADOOP-13208:
-----------------------------------
    Release Note: S3A has optimized the listFiles method by doing a bulk listing of all entries
under a path in a single S3 operation instead of recursively walking the directory tree. 
The listLocatedStatus method has been optimized by fetching results from S3 lazily as the
caller traverses the returned iterator instead of doing an eager fetch of all possible results.

> S3A listFiles(recursive=true) to do a bulk listObjects instead of walking the pseudo-tree
of directories
> --------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-13208
>                 URL: https://issues.apache.org/jira/browse/HADOOP-13208
>             Project: Hadoop Common
>          Issue Type: Sub-task
>          Components: fs/s3
>    Affects Versions: 2.8.0
>            Reporter: Steve Loughran
>            Assignee: Steve Loughran
>            Priority: Minor
>             Fix For: 2.9.0
>
>         Attachments: HADOOP-13208-branch-2-001.patch, HADOOP-13208-branch-2-007.patch,
HADOOP-13208-branch-2-008.patch, HADOOP-13208-branch-2-009.patch, HADOOP-13208-branch-2-010.patch,
HADOOP-13208-branch-2-011.patch, HADOOP-13208-branch-2-012.patch, HADOOP-13208-branch-2-017.patch,
HADOOP-13208-branch-2-018.patch, HADOOP-13208-branch-2-019.patch, HADOOP-13208-branch-2-020.patch,
HADOOP-13208-branch-2-021.patch
>
>   Original Estimate: 24h
>  Remaining Estimate: 24h
>
> A major cost in split calculation against object stores turns out be listing the directory
tree itself. That's because against S3, it takes S3A two HEADs and two lists to list the content
of any directory path (2 HEADs + 1 list for getFileStatus(); the next list to query the contents).
> Listing a directory could be improved slightly by combining the final two listings. However,
a listing of a directory tree will still be O(directories). In contrast, a recursive {{listFiles()}}
operation should be implementable by a bulk listing of all descendant paths; one List operation
per thousand descendants. 
> As the result of this call is an iterator, the ongoing listing can be implemented within
the iterator itself



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: common-issues-help@hadoop.apache.org


Mime
View raw message