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https://issues.apache.org/jira/browse/HADOOP-15027?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16248362#comment-16248362
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wujinhu edited comment on HADOOP-15027 at 11/11/17 6:40 AM:
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Hi Steve Loughran
Thanks for the comments and your suggestions are very helpful. I will follow
your suggestions about thread pool and retry logic.
For random IO, it is true that my implementation will not work well.
It seems HADOOP-14535 is similar with what os does.
Operation system starts to sequential read-ahead when one of the following
conditions satisfies:
* first read from a file and seek pos is 0
* current read and previous read are continuous in this file
Otherwise, it is random IO.
I will take a look at these two issues and continue to improve this.
was (Author: wujinhu):
Hi Steve Loughran
Thanks for the comments and your suggestions are very helpful. I will follow
your suggestions about thread pool and retry logic.
For random IO, it is true that my implementation will not work well.
It seems HADOOP-14535 is similar with what os does.
Operation system starts to sequential read-ahead when one of the following
conditions satisfies:
* first read from a file and seek pos is 0
* current read and previous read are continuous in this file
Otherwise, it is random IO.
I will take a look at these two issues and continue to improve this.
> Improvements for Hadoop read from AliyunOSS
> -------------------------------------------
>
> Key: HADOOP-15027
> URL: https://issues.apache.org/jira/browse/HADOOP-15027
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/oss
> Affects Versions: 3.0.0
> Reporter: wujinhu
> Assignee: wujinhu
> Attachments: HADOOP-15027.001.patch
>
>
> Currently, read performance is poor when Hadoop reads from AliyunOSS. It
> needs about 1min to read 1GB from OSS.
> Class AliyunOSSInputStream uses single thread to read data from AliyunOSS,
> so we can refactor this by using multi-thread pre read to improve this.
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