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https://issues.apache.org/jira/browse/HADOOP-12356?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15062809#comment-15062809
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Wangda Tan commented on HADOOP-12356:
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Hi [~elgoiri]/[~cnauroth],
Looked at patch and discussions:
bq. Inigo Goiri, my understanding of the resource monitoring code at this layer
is that it needs to track utilization as a percentage, not in units of vcores.
I'd also be concerned that changing this calculation could cause unusual
effects during a rolling upgrade scenario, when some NodeManagers are running
the old calculation and some NodeManagers are running the new calculation. I
expect Wangda can give us a more definitive answer.
Since the ResourceUtilization is in 2.8.0 only, I think the rolling upgrade is
not an issue.
I'm wondering if we have different behaviors in SysInfoLinux and SysInfoWindows
to get CPU usage:
- Linux normalized to 0-100%: a node with 8 cores, and usages are all 50%, the
returned accumulated usage after normalization is 50%.
- Windows is not normalized to 0-100%: a node with 8 cores, and usages are all
50%, the returned accumulated usage is 400%.
I think we should make sure the two SysInfo implementation has consistency
behavior, maybe we need add the behavior description to SysInfo#getCPUUsage
java docs.
I'm fine with the change of NodeResourceMonitorImpl if SysInfoWindows/Linux
both normalized usage to 0-100%.
> CPU usage statistics on Windows
> -------------------------------
>
> Key: HADOOP-12356
> URL: https://issues.apache.org/jira/browse/HADOOP-12356
> Project: Hadoop Common
> Issue Type: Bug
> Components: util
> Environment: CPU: Intel Xeon
> OS: Windows server
> Reporter: Yunqi Zhang
> Assignee: Yunqi Zhang
> Labels: easyfix, newbie, patch
> Attachments: 0001-Correct-the-CPU-usage-calcualtion.patch,
> 0001-Correct-the-CPU-usage-calcualtion.patch, HADOOP-12356-v3.patch
>
> Original Estimate: 2h
> Remaining Estimate: 2h
>
> The CPU usage information on Windows is computed incorrectly. The proposed
> patch fixes the issue, and unifies the the interface with Linux.
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