Negative collection_offset Causes Multiple Executions

[network-monitoring]

Relevant telegraf.conf

/etc/telegraf# cat telegraf.conf
[[inputs.exec]]
  interval = "30s"
  commands = ["python3 /etc/telegraf/test.py"]
  timeout = "3s"
  collection_offset = "-15s"
  data_format = "influx"

[[outputs.file]]
  files = ["stdout", "/etc/telegraf/test_output.txt"]


/etc/telegraf# cat test.py 
print("metric,tag1=1,tag2=2 value=1")

Logs from Telegraf

2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped
2025-12-31T13:07:48Z D! [inputs.exec] Previous collection has not completed; scheduled collection skipped

System info

Ubuntu 24.04.3 , Telegraf 1.37.0

Docker

When running with a negative offset Telegraf is executing the python script multiple times, when running with a positive offset there are no issues.

Steps to reproduce

1. Copy telegraf.conf config above to /etc/telegraf folder.
2. Copy python script to /etc/telegraf folder and make executable.
3. Run /usr/bin/telegraf --config telegraf.conf with the config of collection_offset = "-15s" to see the problem, run the same command again with collection_offset = "5s" and the issue no longer happens.
   ...

Expected behavior

I would expect telegraf to run the command / script once at 15s before the set interval rate.

Actual behavior

I appears to be running it multiple times and printing the results multiple times.

Additional info

No response

[Hipska]

I don't think any of the durations (jitter, interval, offset) are supposed to be negative.