HDDS-14110. [DiskBalancer] Show EstimatedBytesToMove only during active balancing and improve threshold check message #9465

Gargi-jais11 · 2025-12-09T08:36:40Z

What changes were proposed in this pull request?

EstimatedBytesToMoved and EstimatedTimeLeft should not be shown up if no container movement happens.
Improve threshold validation error message. When running the DiskBalancer update command with a threshold value of 100.0, the operation fails on all datanodes with the following error:

bash> ozone admin datanode diskbalancer update -t 100.0 --in-service-datanodes
Error on node [DN-1]: Threshold must be a percentage(double) in the range 0 to 100.

A threshold of 0 means any deviation from ideal usage (even 0.01%) triggers
container movement

This leads to excessive and continuous balancing operations and results in unnecessary I/O overhead and resource consumption
A Threshold value can never be 100.0% as it would mean allow moving 100% of a disk's contents, effectively emptying one disk.
Suggested improvement:
Rather the error message should clarify that 0 and 100 is excluded. The validation is being updated to exclude 0, requiring threshold to be in
the range (0, 100) exclusive.
new error msg:

Error on node [DN-1]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-14110

How was this patch tested?

Added check for estimatedBytes in unit test TestDiskBalancerService.
Tested manually:
before patch:

bash-5.1$ ozone admin datanode diskbalancer status --in-service-datanodes
Status result:
Datanode                            Status          Threshold(%)    BandwidthInMB   Threads      StopAfterDiskEven    SuccessMove  FailureMove  BytesMoved(MB)  EstBytesToMove(MB) EstTimeLeft(min)    
ozone-datanode-5.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               638                2                   
ozone-datanode-3.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               1                  1                   
ozone-datanode-4.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               1                  1                   
ozone-datanode-2.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               698                2                   
ozone-datanode-1.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               3                  1                   

Note: Estimated time left is calculated based on the estimated bytes to move and the configured disk bandwidth.

After code chnages output fixed:

bash-5.1$ ozone admin datanode diskbalancer report --in-service-datanodes
Report result:
Datanode                                           VolumeDensity
ozone-datanode-2.ozone_default                     8.413243594594944E-4
ozone-datanode-5.ozone_default                     8.296842069073773E-4
ozone-datanode-3.ozone_default                     7.682500684380311E-4
ozone-datanode-1.ozone_default                     7.585499413112762E-4
ozone-datanode-4.ozone_default                     7.507898396098833E-4

bash-5.1$ ozone admin datanode diskbalancer status --in-service-datanodes
Status result:
Datanode                            Status          Threshold(%)    BandwidthInMB   Threads      StopAfterDiskEven    SuccessMove  FailureMove  BytesMoved(MB)  EstBytesToMove(MB) EstTimeLeft(min)    
ozone-datanode-1.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               0                  0                   
ozone-datanode-4.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               0                  0                   
ozone-datanode-3.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               0                  0                   
ozone-datanode-5.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               0                  0                   
ozone-datanode-2.ozone_default      RUNNING         0.0001          10              5            false                0            0            0               0                  0                   

Note: Estimated time left is calculated based on the estimated bytes to move and the configured disk bandwidth.

Threshold error output:

bash-5.1$ ozone admin datanode diskbalancer start -t 0 --in-service-datanodes
Error on node [172.18.0.11:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.10:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.8:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.9:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.7:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Failed to start DiskBalancer on nodes: [172.18.0.11:19864, 172.18.0.10:19864, 172.18.0.8:19864, 172.18.0.9:19864, 172.18.0.7:19864]
bash-5.1$ ozone admin datanode diskbalancer start -t 100 --in-service-datanodes
Error on node [172.18.0.11:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.10:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.8:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.9:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Error on node [172.18.0.7:19864]: Threshold must be a percentage(double) in the range 0 to 100 both exclusive.
Failed to start DiskBalancer on nodes: [172.18.0.11:19864, 172.18.0.10:19864, 172.18.0.8:19864, 172.18.0.9:19864, 172.18.0.7:19864]
bash-5.1$ ozone admin datanode diskbalancer start -t 0.001 --in-service-datanodes
Started DiskBalancer on all IN_SERVICE nodes.

…eshold error msg improve

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Pull request overview

This PR addresses two issues in the DiskBalancer service: (1) preventing the display of EstimatedBytesToMove and EstimatedTimeLeft when no container movement is occurring, and (2) improving threshold validation to exclude boundary values 0 and 100 with a clearer error message.

Key Changes:

Updated threshold validation to exclude 0 and 100 (changed from < 0d to <= 0d), preventing edge cases that would cause excessive or meaningless balancing
Modified getDiskBalancerInfo() to only calculate and report bytesToMove when containers are actively being balanced (RUNNING state AND non-empty inProgressContainers)
Enhanced error message to clarify that the threshold range is exclusive: "Threshold must be a percentage(double) in the range 0 to 100 both exclusive."

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
`hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/diskbalancer/DiskBalancerConfiguration.java`	Updated threshold validation to exclude 0 and 100, and improved error message clarity
`hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/diskbalancer/DiskBalancerService.java`	Added check for non-empty `inProgressContainers` before calculating `bytesToMove` and updated comments
`hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/diskbalancer/TestDiskBalancerService.java`	Added test coverage for the new `inProgressContainers` check in `getDiskBalancerInfo()`

Comments suppressed due to low confidence (1)

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/diskbalancer/DiskBalancerService.java:724

getInProgressContainers exposes the internal representation stored in field inProgressContainers. The value may be modified after this call to getInProgressContainers.

  public Set<ContainerID> getInProgressContainers() {

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Copilot · 2025-12-09T09:10:13Z

.../src/main/java/org/apache/hadoop/ozone/container/diskbalancer/DiskBalancerConfiguration.java

+    if (threshold <= 0d || threshold >= 100d) {
      throw new IllegalArgumentException(
-          "Threshold must be a percentage(double) in the range 0 to 100.");
+          "Threshold must be a percentage(double) in the range 0 to 100 both exclusive.");
    }


The threshold validation logic has been changed to exclude both 0 and 100 (using <= 0d instead of < 0d). However, there are no tests validating this boundary condition. Consider adding test cases to verify that:

Threshold values of 0 and 100 are rejected with the appropriate error message

Valid threshold values like 0.001 and 99.999 are accepted

This will ensure the validation logic works correctly and prevent regressions.

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corrected to show estBytesToMove only during active balancing and thr…

4a2e668

…eshold error msg improve

Gargi-jais11 marked this pull request as ready for review December 9, 2025 08:37

ChenSammi requested a review from Copilot December 9, 2025 09:03

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HDDS-14110. [DiskBalancer] Show EstimatedBytesToMove only during active balancing and improve threshold check message #9465

HDDS-14110. [DiskBalancer] Show EstimatedBytesToMove only during active balancing and improve threshold check message #9465

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HDDS-14110. [DiskBalancer] Show EstimatedBytesToMove only during active balancing and improve threshold check message #9465

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HDDS-14110. [DiskBalancer] Show EstimatedBytesToMove only during active balancing and improve threshold check message #9465

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Gargi-jais11 commented Dec 9, 2025

What changes were proposed in this pull request?

What is the link to the Apache JIRA

How was this patch tested?

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