[ 
https://issues.apache.org/jira/browse/HDFS-11886?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16156002#comment-16156002
 ] 

Anu Engineer commented on HDFS-11886:
-------------------------------------

[~cheersyang] / [~vagarychen] / [~xyao] I am posting this JIRA as a post merge 
work item. Do you guys feel that this needs to be done before the ozone branch 
merge ? 


> Ozone : Optimize putKey operation to be async and consensus
> -----------------------------------------------------------
>
>                 Key: HDFS-11886
>                 URL: https://issues.apache.org/jira/browse/HDFS-11886
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: ozone
>            Reporter: Chen Liang
>            Assignee: Weiwei Yang
>              Labels: OzonePostMerge
>         Attachments: design-notes-putkey.pdf
>
>
> Ozone's putKey operations involve a couple steps:
> 1. KSM calls allocateBlock to SCM, writes this info to KSM's local metastore
> 2. allocatedBlock gets returned to client, client checks to see if container 
> needs to be created on datanode, if yes, create the container
> 3. writes the data to container.
> it is possible that 1 succeeded, but 2 or 3 failed, in this case there will 
> be an entry in KSM's local metastore, but the key is actually nowhere to be 
> found. We need to revert 1 is 2 or 3 failed in this case. 
> To resolve this, we need at least two things to be implemented first.
> 1. We need deleteKey() to be added KSM first. 
> 2. We also need container reports to be implemented first such that SCM can 
> track whether the container is actually added.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org

Reply via email to