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https://issues.apache.org/jira/browse/HDDS-14926?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Gargi Jaiswal updated HDDS-14926:
---------------------------------
    Status: Patch Available  (was: In Progress)

> Allow QUASI_CLOSED containers in DiskBalancer with improved debug logging for 
> containers
> ----------------------------------------------------------------------------------------
>
>                 Key: HDDS-14926
>                 URL: https://issues.apache.org/jira/browse/HDDS-14926
>             Project: Apache Ozone
>          Issue Type: Sub-task
>            Reporter: Gargi Jaiswal
>            Assignee: Gargi Jaiswal
>            Priority: Major
>              Labels: pull-request-available
>
> Currently DiskBalancer only supports CLOSED containers to be moved but if 
> user wants to also move quasi closed containers then we should support that 
> as well.
> *1st Improvement:*
> Below scenario can happen in real, so  Disk balancer can only attempt those 
> {*}10 CLOSED containers{*}. Even if it moves all 10 successfully, disk A 
> might drop only from 90% → 85% — nowhere near balance. The QUASI_CLOSED 
> containers are the real bulk occupying the space and disk balancer is 
> completely blind to them.
> {code:java}
> Disk A: 90% utilized 
> ├── 600 containers: QUASI_CLOSED 
> └── 10 containers: CLOSED 
> Disk B: 10% utilized 
> Disk C: 11% utilized{code}
> Added a config `hdds.datanode.disk.balancer.include.non.standard.containers` 
> **default=false**.  If true, balancer include non-standard states, i.e, 
> QUASI_CLOSED. So both CLOSED and QUASI_CLOSED state containers are eligible 
> for move. If false (default), balancer only moves CLOSED containers.
>  
> *2nd Improvement:*
> We need to add debug logs for *chooseContainer* method as user might not 
> understand why if they have over and under utilised volume still container is 
> not moved. This parts needs more clarification. Because I see in escalation 
> it helped a lot with balancer debug logs for container not choose to identify 
> what state the contianer or volume was in.
> I suggest adding these logs for container not choose :
>  
> {code:java}
> // This debug will help us to understand what state container was because of 
> which it not moved 
> LOG.debug("Skipping container {} from volume {}: state is {} (only CLOSED is 
> eligible)", containerId, src.getStorageID(), containerData.getState());
> // It can happen a container size exceeds the usable space on that dn 
> LOG.debug("Skipping container {} ({}B) from volume {}: exceeds destination {} 
> " + "usable space {}B", containerId, containerSize, src.getStorageID(), 
> dst.getStorageID(), usableSpace);
> // this shows would push destination utilization over upper threshold 
> LOG.debug("Skipping container {} ({}B) from volume {}: moving to {} would " + 
> "result in utilization {} exceeding upper threshold {}", containerId, 
> containerSize, src.getStorageID(), dst.getStorageID(), newUtilization, 
> upperThreshold);{code}
> For message like “{color:#de350b}{{No suitable container found for 
> destination {}, trying next volume."}}{color}. we can improve it to 
> {color:#00875a}“{{{}No suitable CLOSED state and QUASI_CLOSED state container 
> found for destination {}, trying next volume.{}}}{color} something like this. 



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