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https://issues.apache.org/jira/browse/HDFS-9945?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15195386#comment-15195386
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Kihwal Lee commented on HDFS-9945:
----------------------------------

HDFS-2043 TestHFlush
HDFS-9780 TestRollingFileSystemSinkWithSecureHdfs
HDFS-9950 TestDecommissioningStatus
HDFS-10169 TestEditLog 
HDFS-9767 TestFileAppend
HDFS-6532 TestCrcCorruption
I will work on some of these.

The two checkstyle warnings are about the existing method length being over 150 
lines.

> Datanode command for evicting writers
> -------------------------------------
>
>                 Key: HDFS-9945
>                 URL: https://issues.apache.org/jira/browse/HDFS-9945
>             Project: Hadoop HDFS
>          Issue Type: New Feature
>          Components: datanode
>            Reporter: Kihwal Lee
>            Assignee: Kihwal Lee
>         Attachments: HDFS-9945.patch, HDFS-9945.v2.patch
>
>
> It will be useful if there is a command to evict writers from a datanode. 
> When a set of datanodes are being decommissioned, they can get blocked by 
> slow writers at the end.  It was rare in the old days since mapred jobs 
> didn't last too long, but with many different types of apps running on 
> today's YARN cluster, we are often see very long tail in datanode 
> decommissioning.
> I propose a new dfsadmin command, {{evictWriters}}, to be added. I initially 
> thought about having namenode automatically telling datanodes on 
> decommissioning, but realized that having a command is more flexible. E.g. 
> users can choose not to do this at all, choose when to evict writers, or 
> whether to try multiple times for whatever reasons.



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