[ 
https://issues.apache.org/jira/browse/HDFS-6382?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14012591#comment-14012591
 ] 

Andrew Wang commented on HDFS-6382:
-----------------------------------

Even if implementing security was a major hurdle (and I really don't think it 
is as hard as you think, considering we have quite a few examples of Hadoop 
auth besides the NN), the rest of Chris's points still stand. I also think that 
semantically, a TTL is not an expected type of file attribute for those of us 
with a Unix background, which leads to TOCTOU issues like Chris also pointed 
out even if just because of user expectations.

So, at this point, I think there are strong technical reasons not to implement 
this in the NN, and strong reasons to do this type of data lifecycle management 
externally.

> 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)

Reply via email to