A number of environment variables can be used to configure the behavior of the library. There are also functions to configure this behavior in code. The environment variables are convenient when troubleshooting problems.
Endpoint Overrides
GOOGLE_CLOUD_CPP_DATAPROC_METASTORE_ENDPOINT=...overrides theEndpointOption(which defaults to "metastore.googleapis.com") used byMakeDataprocMetastoreConnection().
GOOGLE_CLOUD_CPP_DATAPROC_METASTORE_FEDERATION_ENDPOINT=...overrides theEndpointOption(which defaults to "metastore.googleapis.com") used byMakeDataprocMetastoreFederationConnection().
GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc: turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured your own logging backend, you should also setGOOGLE_CLOUD_CPP_ENABLE_CLOGto produce any output on the program's console.
See Also
google::cloud::TracingComponentsOptionGOOGLE_CLOUD_CPP_TRACING_OPTIONS=...: modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.
See Also
google::cloud::GrpcTracingOptionsOptionGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes: turns on logging in the library, basically the library always "logs" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThis page details environment variables and versioned documentation for configuring the behavior of the Dataproc Metastore C++ library, with the latest version being 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_CPP_DATAPROC_METASTORE_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_DATAPROC_METASTORE_FEDERATION_ENDPOINT\u003c/code\u003e variables are used to override the default endpoints for their respective connection methods.\u003c/p\u003e\n"],["\u003cp\u003eSetting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e will turn on tracing for gRPC calls, requiring \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e to also be set to produce console output, while \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e can be used to modify tracing behavior.\u003c/p\u003e\n"],["\u003cp\u003eEnabling logging in the library can be done by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e, allowing the logging infrastructure to print to a backend.\u003c/p\u003e\n"],["\u003cp\u003eWhile \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e variable is used to configure the GCP project in examples and integration testing, it has no effect within the library itself.\u003c/p\u003e\n"]]],[],null,["Version 2.21.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/metastore/latest/metastore-env)\n- [2.41.0](/cpp/docs/reference/metastore/2.41.0/metastore-env)\n- [2.40.0](/cpp/docs/reference/metastore/2.40.0/metastore-env)\n- [2.39.0](/cpp/docs/reference/metastore/2.39.0/metastore-env)\n- [2.38.0](/cpp/docs/reference/metastore/2.38.0/metastore-env)\n- [2.37.0](/cpp/docs/reference/metastore/2.37.0/metastore-env)\n- [2.36.0](/cpp/docs/reference/metastore/2.36.0/metastore-env)\n- [2.35.0](/cpp/docs/reference/metastore/2.35.0/metastore-env)\n- [2.34.0](/cpp/docs/reference/metastore/2.34.0/metastore-env)\n- [2.33.0](/cpp/docs/reference/metastore/2.33.0/metastore-env)\n- [2.32.0](/cpp/docs/reference/metastore/2.32.0/metastore-env)\n- [2.31.0](/cpp/docs/reference/metastore/2.31.0/metastore-env)\n- [2.30.0](/cpp/docs/reference/metastore/2.30.0/metastore-env)\n- [2.29.0](/cpp/docs/reference/metastore/2.29.0/metastore-env)\n- [2.28.0](/cpp/docs/reference/metastore/2.28.0/metastore-env)\n- [2.27.0](/cpp/docs/reference/metastore/2.27.0/metastore-env)\n- [2.26.0](/cpp/docs/reference/metastore/2.26.0/metastore-env)\n- [2.25.1](/cpp/docs/reference/metastore/2.25.1/metastore-env)\n- [2.24.0](/cpp/docs/reference/metastore/2.24.0/metastore-env)\n- [2.23.0](/cpp/docs/reference/metastore/2.23.0/metastore-env)\n- [2.22.1](/cpp/docs/reference/metastore/2.22.1/metastore-env)\n- [2.21.0](/cpp/docs/reference/metastore/2.21.0/metastore-env)\n- [2.20.0](/cpp/docs/reference/metastore/2.20.0/metastore-env)\n- [2.19.0](/cpp/docs/reference/metastore/2.19.0/metastore-env)\n- [2.18.0](/cpp/docs/reference/metastore/2.18.0/metastore-env)\n- [2.17.0](/cpp/docs/reference/metastore/2.17.0/metastore-env)\n- [2.16.0](/cpp/docs/reference/metastore/2.16.0/metastore-env)\n- [2.15.1](/cpp/docs/reference/metastore/2.15.1/metastore-env)\n- [2.14.0](/cpp/docs/reference/metastore/2.14.0/metastore-env)\n- [2.13.0](/cpp/docs/reference/metastore/2.13.0/metastore-env) \n\nEnvironment Variables\n=====================\n\nA number of environment variables can be used to configure the behavior of the library. There are also functions to configure this behavior in code. The environment variables are convenient when troubleshooting problems.\n\nEndpoint Overrides\n------------------\n\n- `GOOGLE_CLOUD_CPP_DATAPROC_METASTORE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"metastore.googleapis.com\") used by `MakeDataprocMetastoreConnection()`.\n- `GOOGLE_CLOUD_CPP_DATAPROC_METASTORE_FEDERATION_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"metastore.googleapis.com\") used by `MakeDataprocMetastoreFederationConnection()`.\n\n###### See Also\n\n[`google::cloud::EndpointOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1EndpointOption.html)\n\nLogging\n-------\n\n`GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`: turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured your own logging backend, you should also set `GOOGLE_CLOUD_CPP_ENABLE_CLOG` to produce any output on the program's console.\n\n###### See Also\n\n[`google::cloud::TracingComponentsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1TracingComponentsOption.html)`GOOGLE_CLOUD_CPP_TRACING_OPTIONS=...`: modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.\n\n###### See Also\n\n[`google::cloud::GrpcTracingOptionsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1GrpcTracingOptionsOption.html)`GOOGLE_CLOUD_CPP_ENABLE_CLOG=yes`: turns on logging in the library, basically the library always \"logs\" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.\n\n###### See Also\n\n[`google::cloud::LogBackend`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogBackend.html)\n\n###### See Also\n\n[`google::cloud::LogSink`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogSink.html)\n\nSetting the Default Project\n---------------------------\n\n`GOOGLE_CLOUD_PROJECT=...`: is used in examples and integration tests to configure the GCP project. This has no effect in the library."]]
