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https://issues.apache.org/jira/browse/YUNIKORN-1105?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Wilfred Spiegelenburg resolved YUNIKORN-1105.
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Fix Version/s: 1.0.0
Resolution: Fixed
both shim and web UI changes are in
> Rethink memory resource conversion to MB
> ----------------------------------------
>
> Key: YUNIKORN-1105
> URL: https://issues.apache.org/jira/browse/YUNIKORN-1105
> Project: Apache YuniKorn
> Issue Type: Improvement
> Components: shim - kubernetes
> Reporter: Wilfred Spiegelenburg
> Assignee: Craig Condit
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.0.0
>
>
> The choice to represent memory in units of MB and not in bytes comes with a
> side effect. We convert a pod or node memory size into something that is a MB
> (10 based).
> Not everything is expressible in whole MB. We round up to the nearest MB. 1
> byte over and we use the whole MB. This means that a node looks larger in
> YuniKorn than it really is. It is less than a MB but it can still cause an
> issue with a pod just fitting or not fitting.
> As an example: a pods needs exactly 10MB, 10,000,000 bytes. A node in
> YuniKorn shows 10MB free but in reality it is not 10,000,000 bytes but only
> 9,000,001.
> It can also happen the other way around. The pod asks for 9,000,001 bytes,
> YuniKorn sees it as 10MB. The node in YuniKorn shows 9MB free but in reality
> the node has 9,500,000 free as a previous pod we have scheduled did not use
> 10MB but only 9,500,000. YuniKorn fails to place the pod, The auto scaler
> says there is enough room to place the pod.
> I know I am splitting hairs here but it is a real possibility. These failures
> are really hard to track down and link back. YuniKorn schedules the pod and
> the node bind fails with not enough resources or scale up fails to trigger
> when expected.
> With the choice of milli for cpu we have far less of an issue as K8s does not
> support more than 3 decimal places. In other words the smallest value used in
> K8s is {{1m}} for cpu.
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