{"record":{"id":"6b8754c3463e029b","repo":"mlflow/mlflow","slug":"failure-attempting-to-register-request-header-prov","errorCode":null,"errorMessage":"Failure attempting to register request header provider \"{}\": {}","messagePattern":"Failure attempting to register request header provider \"(.+?)\": (.+?)","errorType":"console","errorClass":"UserWarning","httpStatus":null,"severity":"warning","filePath":"mlflow/tracking/request_header/registry.py","lineNumber":28,"sourceCode":"from mlflow.utils.plugins import get_entry_points\n\n_logger = logging.getLogger(__name__)\n\n\nclass RequestHeaderProviderRegistry:\n    def __init__(self):\n        self._registry = []\n\n    def register(self, request_header_provider):\n        self._registry.append(request_header_provider())\n\n    def register_entrypoints(self):\n        \"\"\"Register tracking stores provided by other packages\"\"\"\n        for entrypoint in get_entry_points(\"mlflow.request_header_provider\"):\n            try:\n                self.register(entrypoint.load())\n            except (AttributeError, ImportError) as exc:\n                warnings.warn(\n                    'Failure attempting to register request header provider \"{}\": {}'.format(\n                        entrypoint.name, str(exc)\n                    ),\n                    stacklevel=2,\n                )\n\n    def __iter__(self):\n        return iter(self._registry)\n\n\n_request_header_provider_registry = RequestHeaderProviderRegistry()\n_request_header_provider_registry.register(DatabricksRequestHeaderProvider)\n_request_header_provider_registry.register(DefaultRequestHeaderProvider)\n\n_request_header_provider_registry.register_entrypoints()\n\n\ndef resolve_request_headers(request_headers=None):","sourceCodeStart":10,"sourceCodeEnd":46,"githubUrl":"https://github.com/mlflow/mlflow/blob/6a27f2decc0b76eb1b54af31849784addb357dbc/mlflow/tracking/request_header/registry.py#L10-L46","documentation":"The request-header provider registry loads `mlflow.request_header_provider` entry points. Plugins that raise AttributeError or ImportError at import time produce this warning and are skipped, so their headers will not be attached to outgoing requests.","triggerScenarios":"Any installed package exposing mlflow.request_header_provider whose module/class fails on load.","commonSituations":"Header-injection plugins (e.g. tracing/correlation-id providers) broken after environment changes or partial upgrades.","solutions":["Fix or reinstall the plugin named in the warning.","Uninstall the plugin if its headers are not needed.","Recreate the environment to clear stale/broken entry points."],"exampleFix":"// before\nimport my_header_provider  # AttributeError: module has no attribute 'MyProvider'\n// after\n# pip install --force-reinstall my-mlflow-header-provider","handlingStrategy":"validation","validationCode":"from importlib.metadata import entry_points\nfor ep in entry_points(group=\"mlflow.request_header_provider\"):\n    try:\n        ep.load()\n    except Exception as e:\n        print(f\"broken header provider {ep.name}: {e}\")","typeGuard":null,"tryCatchPattern":"import warnings\nwith warnings.catch_warnings(record=True) as w:\n    warnings.simplefilter(\"always\")\n    client.search_experiments()\nfor warn in w:\n    if \"request header provider\" in str(warn.message):\n        fix_plugin(warn)","preventionTips":["Verify header providers load after every environment rebuild.","Declare all plugin dependencies explicitly in package metadata.","Watch for this warning when custom headers (e.g. tracing IDs) silently stop being sent."],"tags":["plugins","entrypoint","import-error"],"backgroundTag":"plugin-entrypoint-load-failure","analyzedSha":"6a27f2decc0b76eb1b54af31849784addb357dbc","analyzedAt":"2026-08-29T20:54:51.419Z","schemaVersion":2},"datasetVersion":"2026-08-29T22:17:34.462Z"}