Details
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Improvement
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Status: Closed
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Major
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Resolution: Fixed
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0.21.0
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None
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None
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Incompatible change, Reviewed
Description
Currently the key to Block is block id + generation stamp. I would propose to change it to be only block id. This is based on the following properties of the dfs cluster:
1. On each datanode only one replica of block exists. Therefore there is only one generation of a block.
2. NameNode has only one entry for a block in its blocks map.
With this change, search for a block/replica's meta information is easier since most of the time we know a block's id but may not know its generation stamp.
Attachments
Attachments
Issue Links
- blocks
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HDFS-509 Redesign DataNode volumeMap to include all types of Replicas
- Resolved
- relates to
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HADOOP-2656 Support for upgrading existing cluster to facilitate appends to HDFS files
- Closed