hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hangjun Ye (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-6382) HDFS File/Directory TTL
Date Thu, 29 May 2014 16:09:01 GMT

    [ https://issues.apache.org/jira/browse/HDFS-6382?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14012480#comment-14012480
] 

Hangjun Ye commented on HDFS-6382:
----------------------------------

bq. This logic is subject to time of check/time of use race conditions, possibly resulting
in incorrect deletion of data. For example, imagine the following sequence: ...

It doesn't sound a "race condition" to me. We could consider TTL as an "independent" attribute
of file, just like file owner and replication number. In the above scenario,  it seems to
work as expected, since the admin only changes the owner of /file1 but leaves the TTL attribute
as is and so the TTL should be still effective. If the admin doesn't want it to happen, he/she
should "unset" the TTL attribute (i.e. set it to infinity) firstly before he/she changes the
owner of /file1, and the new owner of /file1 could set a new TTL attribute later if needed.

> HDFS File/Directory TTL
> -----------------------
>
>                 Key: HDFS-6382
>                 URL: https://issues.apache.org/jira/browse/HDFS-6382
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: hdfs-client, namenode
>    Affects Versions: 2.4.0
>            Reporter: Zesheng Wu
>            Assignee: Zesheng Wu
>
> In production environment, we always have scenario like this, we want to backup files
on hdfs for some time and then hope to delete these files automatically. For example, we keep
only 1 day's logs on local disk due to limited disk space, but we need to keep about 1 month's
logs in order to debug program bugs, so we keep all the logs on hdfs and delete logs which
are older than 1 month. This is a typical scenario of HDFS TTL. So here we propose that hdfs
can support TTL.
> Following are some details of this proposal:
> 1. HDFS can support TTL on a specified file or directory
> 2. If a TTL is set on a file, the file will be deleted automatically after the TTL is
expired
> 3. If a TTL is set on a directory, the child files and directories will be deleted automatically
after the TTL is expired
> 4. The child file/directory's TTL configuration should override its parent directory's
> 5. A global configuration is needed to configure that whether the deleted files/directories
should go to the trash or not
> 6. A global configuration is needed to configure that whether a directory with TTL should
be deleted when it is emptied by TTL mechanism or not.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message