HDDS-15667. containerbalancer status: show stop reason and iteration details after stop

[sreejasahithi]

What changes were proposed in this pull request?

Currently, when Container Balancer is stopped, ozone admin containerbalancer status only reports: "ContainerBalancer is Not Running."

It would be helpful if after stop, status shows the last known run state:

• Stop reason (also in non-verbose mode)
• Start/stop timestamps, balancing duration, and configuration used ( with --verbose flag)
• Last iteration details ( with --verbose flag)
• Iteration history details (with --verbose -H flag)

What is the link to the Apache JIRA

HDDS-15667

How was this patch tested?

Tested manually in docker cluster and added test cases.
Sample runs:

bash-5.1$ ozone admin containerbalancer status --verbose --history
ContainerBalancer is Not Running.
Stop reason: INITIALIZATION_FAILED
Message: Failed to initialize a container balancer iteration. Details: iteration number 1, Did not find any unbalanced Datanodes.
Started at: 2026-07-14 05:09:39
Stopped at: 2026-07-14 05:09:39
Balancing duration: 0s
Container Balancer Configuration values:
Key Value
Threshold 10
Max Datanodes to Involve per Iteration(percent) 20
Max Size to Move per Iteration 500GB
Max Size Entering Target per Iteration 26GB
Max Size Leaving Source per Iteration 26GB
Number of Iterations 10
Time Limit for Single Container's Movement 65min
Time Limit for Single Container's Replication 50min
Interval between each Iteration 0min
Whether to Enable Network Topology false
Whether to Trigger Refresh Datanode Usage Info false
Container IDs to Include in Balancing None
Container IDs to Exclude from Balancing None
Datanodes Specified to be Balanced None
Datanodes Excluded from Balancing None
Last iteration info:
-
Completed iteration history:
-

bash-5.1$ ozone admin containerbalancer status --verbose -H
ContainerBalancer is Not Running.
Stop reason: USER_REQUESTED
Message: Stopped by user request.
Started at: 2026-07-13 07:24:20
Stopped at: 2026-07-13 07:26:14
Balancing duration: 1m 54s
Container Balancer Configuration values:
Key Value
Threshold 0.1
Max Datanodes to Involve per Iteration(percent) 100
Max Size to Move per Iteration 500GB
Max Size Entering Target per Iteration 26GB
Max Size Leaving Source per Iteration 26GB
Number of Iterations 3
Time Limit for Single Container's Movement 65min
Time Limit for Single Container's Replication 50min
Interval between each Iteration 0min
Whether to Enable Network Topology false
Whether to Trigger Refresh Datanode Usage Info false
Container IDs to Include in Balancing None
Container IDs to Exclude from Balancing None
Datanodes Specified to be Balanced None
Datanodes Excluded from Balancing None
Last iteration info:
Key Value
Iteration number 1
Iteration duration 1m 54s
Iteration result ITERATION_COMPLETED
Size scheduled to move 150 MB
Moved data size 50 MB
Scheduled to move containers 2
Already moved containers 1
Failed to move containers 0
Failed to move containers by timeout 0
Entered data to nodes 79c3cce6-4218-4966-90db-e964c2426473 <- 100 MB
5f5d448c-cfd6-4b6f-9c5e-152d66bbce48 <- 50 MB
Exited data from nodes 790eafdd-7d7f-4c5f-948d-684f43c67437 -> 100 MB
248e72f4-afe2-4070-9e6c-4555c39f86e2 -> 50 MB
Completed iteration history:
-

bash-5.1$ ozone admin containerbalancer start -t 0.1 -d 100 -i 3
Container Balancer started successfully.
bash-5.1$ ozone admin containerbalancer status --verbose -H
ContainerBalancer is Not Running.
Stop reason: CAN_NOT_BALANCE_ANY_MORE
Message: No more eligible container moves were found.
Started at: 2026-07-08 12:45:25
Stopped at: 2026-07-08 12:46:20
Balancing duration: 55s
Container Balancer Configuration values:
Key Value
Threshold 0.1
Max Datanodes to Involve per Iteration(percent) 100
Max Size to Move per Iteration 500GB
Max Size Entering Target per Iteration 26GB
Max Size Leaving Source per Iteration 26GB
Number of Iterations 3
Time Limit for Single Container's Movement 65min
Time Limit for Single Container's Replication 50min
Interval between each Iteration 0min
Whether to Enable Network Topology false
Whether to Trigger Refresh Datanode Usage Info false
Container IDs to Include in Balancing None
Container IDs to Exclude from Balancing None
Datanodes Specified to be Balanced None
Datanodes Excluded from Balancing None
Last iteration info:
Key Value
Iteration number 2
Iteration duration 0s
Iteration result CAN_NOT_BALANCE_ANY_MORE
Size scheduled to move 0 B
Moved data size 0 B
Scheduled to move containers 0
Already moved containers 0
Failed to move containers 0
Failed to move containers by timeout 0
Entered data to nodes
-
Exited data from nodes
-
Completed iteration history:
Key Value
Iteration number 1
Iteration duration 30s
Iteration result ITERATION_COMPLETED
Size scheduled to move 300 MB
Moved data size 300 MB
Scheduled to move containers 3
Already moved containers 3
Failed to move containers 0
Failed to move containers by timeout 0
Entered data to nodes
0c916231-0bc0-4303-910e-a5e3eedbf0c0 <- 100 MB
39b69c76-67aa-4a04-8675-5ad143a63ad7 <- 100 MB
30b0de7b-a6e5-40c3-ab6b-40b35adf85f7 <- 100 MB
Exited data from nodes
1eccc612-654a-4aa2-919f-2b916aa7f43b -> 100 MB
850f87cb-19ab-4188-bfe3-ff83672f8341 -> 100 MB
a6f2b660-ddfb-4738-817e-9a477428365e -> 100 MB

bash-5.1$ ozone admin containerbalancer status
ContainerBalancer is Not Running.
Stop reason: CAN_NOT_BALANCE_ANY_MORE
Message: No more eligible container moves were found.

bash-5.1$ ozone admin containerbalancer start -t 0.1 -d 100 -i 2
Container Balancer started successfully.
bash-5.1$ ozone admin containerbalancer status --verbose -H
ContainerBalancer is Not Running.
Stop reason: COMPLETED_ALL_ITERATIONS
Message: Completed all configured number of iterations.
Started at: 2026-07-08 12:55:17
Stopped at: 2026-07-08 12:56:59
Balancing duration: 1m 42s
Container Balancer Configuration values:
Key Value
Threshold 0.1
Max Datanodes to Involve per Iteration(percent) 100
Max Size to Move per Iteration 500GB
Max Size Entering Target per Iteration 26GB
Max Size Leaving Source per Iteration 26GB
Number of Iterations 2
Time Limit for Single Container's Movement 65min
Time Limit for Single Container's Replication 50min
Interval between each Iteration 0min
Whether to Enable Network Topology false
Whether to Trigger Refresh Datanode Usage Info false
Container IDs to Include in Balancing None
Container IDs to Exclude from Balancing None
Datanodes Specified to be Balanced None
Datanodes Excluded from Balancing None
Last iteration info:
Key Value
Iteration number 2
Iteration duration 36s
Iteration result ITERATION_COMPLETED
Size scheduled to move 100 MB
Moved data size 0 B
Scheduled to move containers 3
Already moved containers 3
Failed to move containers 0
Failed to move containers by timeout 0
Entered data to nodes
1eccc612-654a-4aa2-919f-2b916aa7f43b <- 40 MB
850f87cb-19ab-4188-bfe3-ff83672f8341 <- 40 MB
a6f2b660-ddfb-4738-817e-9a477428365e <- 20 MB
Exited data from nodes
0c916231-0bc0-4303-910e-a5e3eedbf0c0 -> 40 MB
39b69c76-67aa-4a04-8675-5ad143a63ad7 -> 40 MB
30b0de7b-a6e5-40c3-ab6b-40b35adf85f7 -> 20 MB
Completed iteration history:
Key Value
Iteration number 1
Iteration duration 41s
Iteration result ITERATION_COMPLETED
Size scheduled to move 160 MB
Moved data size 160 MB
Scheduled to move containers 3
Already moved containers 3
Failed to move containers 0
Failed to move containers by timeout 0
Entered data to nodes
0c916231-0bc0-4303-910e-a5e3eedbf0c0 <- 80 MB
39b69c76-67aa-4a04-8675-5ad143a63ad7 <- 20 MB
30b0de7b-a6e5-40c3-ab6b-40b35adf85f7 <- 60 MB
Exited data from nodes
1eccc612-654a-4aa2-919f-2b916aa7f43b -> 20 MB
850f87cb-19ab-4188-bfe3-ff83672f8341 -> 80 MB
a6f2b660-ddfb-4738-817e-9a477428365e -> 60 MB

Green CI : https://github.com/sreejasahithi/ozone/actions/runs/28775666320

[ArafatKhan2198]

Thanks for the patch @sreejasahithi
Some comments for you

[rakeshadr]

Thanks @sreejasahithi for working on this. Added a few comments, please go thru it.

[ashishkumar50]

@sreejasahithi Thanks for working on this, Please find the comments inline.

[sreejasahithi]

@ashishkumar50 could you please help re run the checks as the latest commit got green ci in my fork
https://github.com/sreejasahithi/ozone/actions/runs/29241610279

[ashishkumar50]

LGTM

[rakeshadr]

+1 LGTM.

[sarvekshayr]

Thanks @sreejasahithi for the patch, @ArafatKhan2198, @ashishkumar50 and @rakeshadr for the review.