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Guo Ruijing commented on HDFS-6087: ----------------------------------- I think I already resolve Konstantin Shvachko and Tsz Wo Nicholas Sze's comments/concerns. I will wait for your new comments/concerns and update it in document. design motivation is: 1) unify HDFS write/append/truncate 2) the design is base of writable snapshot / snapshot restore (This JIRA is not created to track snapshot items) > Unify HDFS write/append/truncate > -------------------------------- > > Key: HDFS-6087 > URL: https://issues.apache.org/jira/browse/HDFS-6087 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client > Reporter: Guo Ruijing > Attachments: HDFS Design Proposal.pdf, HDFS Design Proposal_3_14.pdf > > > In existing implementation, HDFS file can be appended and HDFS block can be > reopened for append. This design will introduce complexity including lease > recovery. If we design HDFS block as immutable, it will be very simple for > append & truncate. The idea is that HDFS block is immutable if the block is > committed to namenode. If the block is not committed to namenode, it is HDFS > client’s responsibility to re-added with new block ID. -- This message was sent by Atlassian JIRA (v6.2#6252)