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https://issues.apache.org/jira/browse/HDFS-425?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Allen Wittenauer updated HDFS-425:
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    Summary: fuse has major performance drop on slower machines  (was: Major 
performance drop on slower machines)

> fuse has major performance drop on slower machines
> --------------------------------------------------
>
>                 Key: HDFS-425
>                 URL: https://issues.apache.org/jira/browse/HDFS-425
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: fuse-dfs
>            Reporter: Marc-Olivier Fleury
>            Priority: Minor
>
> When running fuse_dfs on machines that have different CPU characteristics, I 
> noticed that the performance of fuse_dfs is very sensitive to the machine 
> power. 
> The command I used was simply a cat over a rather large amount of data stored 
> on HDFS. Here are the comparative times for the different types of machines:
> Intel(R) Pentium(R) 4 CPU 2.40GHz :                                2 min 40 s 
> Intel(R) Pentium(R) 4 CPU 3.06GHz:                                 1 min 50 s 
> 2 x Intel(R) Pentium(R) 4 CPU 3.00GHz:                           0 min 40 s 
> 2 x Intel(R) Xeon(TM) MP CPU 3.33GHz:                           0 min 28 s 
> Intel(R) Core(TM)2 Quad CPU    Q6600  @ 2.40GHz      0 min 15 s
> I tried to find other explanations for the drop in performance, such as 
> network configuration, or data locality, but the faster machines are the ones 
> that are "further away" from the others considering the network 
> configuration, and that don't run datanodes.
> top shows that the CPU usage of fuse_dfs is between 80-90% on the slower 
> machines, and about 40% on the fastest one.
> This leads me to the conclusion that fuse_dfs consumes a lot of CPU 
> resources, much more than expected.
> Any help or insight concerning this issue will be greatly appreciated, since 
> these difference actually result in days of computations for a given job.
> Thank you



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