●Change8

Migrating to MLflow v3.6.0

Version v3.6.0 introduces 2 breaking changes. This guide details how to update your code.

Released: 11/8/2025

2
Breaking Changes
7
Migration Steps
10
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

mlflow.spark.load_modellog_metricmlflow.entities.Datasetdelete_tracessearch_tracesmlflow.traces.evalmlflow.scorers.register_llm_judgemlflow.scorers.listmlflow.tracesmlflow.tracking

Breaking Changes

●Issue #1

The pmdarima, promptflow, and diviner flavors have been deprecated; replace any usage of these flavors with supported alternatives or remove them from your pipelines.

●Issue #2

Span names no longer include automatic numbering suffixes such as "_1", "_2", etc.; update any code that relied on these suffixes to use the new naming convention.

Migration Steps

  1. 1
    Replace any usage of the deprecated pmdarima, promptflow, or diviner flavors with supported alternatives or remove them from your pipelines.
  2. 2
    Update code that relied on automatically suffixed span names (e.g., "my_span_1") to use the new naming convention without the numeric suffix.
  3. 3
    Review and migrate away from filesystem backends that now emit deprecation warnings; switch to cloud or database‑backed storage as appropriate.
  4. 4
    If you previously registered custom scorers, remove those registrations and use the built‑in scorer registration CLI commands instead.
  5. 5
    Ensure your tracing instrumentation is updated to the new OpenTelemetry integration APIs.
  6. 6
    Verify that any scripts or CI pipelines that invoke `mlflow.spark.load_model` handle Unity Catalog Volume paths correctly.
  7. 7
    Adjust any calls to `log_metric` that passed non‑Dataset objects to now pass `mlflow.entities.Dataset` where required.

Release Summary

MLflow 3.6.0 introduces full OpenTelemetry support, a new Agent Server, extensive tracing and evaluation enhancements, and numerous UI and framework integrations, while deprecating several flavors and changing span naming conventions.

Need More Details?

View the full release notes and all changes for MLflow v3.6.0.

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