Details
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Sub-task
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Status: Resolved
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Major
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Resolution: Fixed
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2.7.1
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None
Description
- Currently, "read(long position, byte[] buffer, int offset, int length)" is not implemented in S3AInputStream (unlike DFSInputStream). So, "readFully(long position, byte[] buffer, int offset, int length)" in S3AInputStream goes through the default implementation of seek(), read(), seek() in FSInputStream.
- However, seek() in S3AInputStream involves re-opening of connection to S3 everytime (https://github.com/apache/hadoop/blob/trunk/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AInputStream.java#L115).
- It would be good to consider having a lazy seek implementation to reduce connection overheads to S3. (e.g Presto implements lazy seek. https://github.com/facebook/presto/blob/master/presto-hive/src/main/java/com/facebook/presto/hive/PrestoS3FileSystem.java#L623)
Attachments
Attachments
Issue Links
- contains
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HADOOP-11874 s3a can throw spurious IOEs on close()
- Resolved
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HADOOP-12976 s3a toString to be meaningful in logs
- Resolved
- depends upon
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HADOOP-12994 Specify PositionedReadable, add contract tests, fix problems
- Resolved
- is related to
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HADOOP-16241 S3AInputStream PositionReadable should perform ranged read on dedicated stream
- Open
- is required by
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HADOOP-12844 Recover when S3A fails on IOException in read()
- Resolved
- relates to
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HIVE-11945 ORC with non-local reads may not be reusing connection to DN
- Closed
(1 relates to)