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_ANALYTICS_HUB_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "analyticshub.googleapis.com") used byMakeAnalyticsHubServiceConnection().
GOOGLE_CLOUD_CPP_BIGQUERY_CONNECTION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigqueryconnection.googleapis.com") used byMakeConnection().
GOOGLE_CLOUD_CPP_BIGQUERY_READ_ENDPOINT=...overrides theEndpointOption(which defaults to "bigquerystorage.googleapis.com") used byMakeBigQueryReadConnection().
GOOGLE_CLOUD_CPP_BIGQUERY_WRITE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigquerystorage.googleapis.com") used byMakeBigQueryWriteConnection().
GOOGLE_CLOUD_CPP_DATA_POLICY_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigquerydatapolicy.googleapis.com") used byMakeDataPolicyServiceConnection().
GOOGLE_CLOUD_CPP_DATA_TRANSFER_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigquerydatatransfer.googleapis.com") used byMakeDataTransferServiceConnection().
GOOGLE_CLOUD_CPP_METASTORE_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "biglake.googleapis.com") used byMakeMetastoreServiceConnection().
GOOGLE_CLOUD_CPP_MIGRATION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigquerymigration.googleapis.com") used byMakeMigrationServiceConnection().
GOOGLE_CLOUD_CPP_RESERVATION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "bigqueryreservation.googleapis.com") used byMakeReservationServiceConnection().
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 document outlines environment variables and their corresponding functions to configure the behavior of the Google Cloud C++ client library, particularly for BigQuery services, offering a range of versions from 2.11.0 up to 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eEndpoint overrides for various BigQuery services can be set via specific environment variables, like \u003ccode\u003eGOOGLE_CLOUD_CPP_BIGQUERY_READ_ENDPOINT\u003c/code\u003e, which is used to customize the connection endpoint used by \u003ccode\u003eMakeBigQueryReadConnection()\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled using \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, which will output the gRPC request and response to the console when \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e is also set.\u003c/p\u003e\n"],["\u003cp\u003eThe environment variable \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS=...\u003c/code\u003e allows the user to modify the behavior of the tracing capabilities of gRPC, including if messages should be output on multiple lines or if fields should be truncated.\u003c/p\u003e\n"],["\u003cp\u003eLogging can be configured within the library by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e, allowing the logging infrastructure to print any logs made to the console, instead of not having any backend to print to.\u003c/p\u003e\n"]]],[],null,["Version 2.18.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/bigquery/latest/bigquery-env)\n- [2.41.0](/cpp/docs/reference/bigquery/2.41.0/bigquery-env)\n- [2.40.0](/cpp/docs/reference/bigquery/2.40.0/bigquery-env)\n- [2.39.0](/cpp/docs/reference/bigquery/2.39.0/bigquery-env)\n- [2.38.0](/cpp/docs/reference/bigquery/2.38.0/bigquery-env)\n- [2.37.0](/cpp/docs/reference/bigquery/2.37.0/bigquery-env)\n- [2.36.0](/cpp/docs/reference/bigquery/2.36.0/bigquery-env)\n- [2.35.0](/cpp/docs/reference/bigquery/2.35.0/bigquery-env)\n- [2.34.0](/cpp/docs/reference/bigquery/2.34.0/bigquery-env)\n- [2.33.0](/cpp/docs/reference/bigquery/2.33.0/bigquery-env)\n- [2.32.0](/cpp/docs/reference/bigquery/2.32.0/bigquery-env)\n- [2.31.0](/cpp/docs/reference/bigquery/2.31.0/bigquery-env)\n- [2.30.0](/cpp/docs/reference/bigquery/2.30.0/bigquery-env)\n- [2.29.0](/cpp/docs/reference/bigquery/2.29.0/bigquery-env)\n- [2.28.0](/cpp/docs/reference/bigquery/2.28.0/bigquery-env)\n- [2.27.0](/cpp/docs/reference/bigquery/2.27.0/bigquery-env)\n- [2.26.0](/cpp/docs/reference/bigquery/2.26.0/bigquery-env)\n- [2.25.1](/cpp/docs/reference/bigquery/2.25.1/bigquery-env)\n- [2.24.0](/cpp/docs/reference/bigquery/2.24.0/bigquery-env)\n- [2.23.0](/cpp/docs/reference/bigquery/2.23.0/bigquery-env)\n- [2.22.1](/cpp/docs/reference/bigquery/2.22.1/bigquery-env)\n- [2.21.0](/cpp/docs/reference/bigquery/2.21.0/bigquery-env)\n- [2.20.0](/cpp/docs/reference/bigquery/2.20.0/bigquery-env)\n- [2.19.0](/cpp/docs/reference/bigquery/2.19.0/bigquery-env)\n- [2.18.0](/cpp/docs/reference/bigquery/2.18.0/bigquery-env)\n- [2.17.0](/cpp/docs/reference/bigquery/2.17.0/bigquery-env)\n- [2.16.0](/cpp/docs/reference/bigquery/2.16.0/bigquery-env)\n- [2.15.1](/cpp/docs/reference/bigquery/2.15.1/bigquery-env)\n- [2.14.0](/cpp/docs/reference/bigquery/2.14.0/bigquery-env)\n- [2.13.0](/cpp/docs/reference/bigquery/2.13.0/bigquery-env)\n- [2.12.0](/cpp/docs/reference/bigquery/2.12.0/bigquery-env)\n- [2.11.0](/cpp/docs/reference/bigquery/2.11.0/bigquery-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_ANALYTICS_HUB_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"analyticshub.googleapis.com\") used by `MakeAnalyticsHubServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_BIGQUERY_CONNECTION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigqueryconnection.googleapis.com\") used by `MakeConnection()`.\n- `GOOGLE_CLOUD_CPP_BIGQUERY_READ_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigquerystorage.googleapis.com\") used by `MakeBigQueryReadConnection()`.\n- `GOOGLE_CLOUD_CPP_BIGQUERY_WRITE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigquerystorage.googleapis.com\") used by `MakeBigQueryWriteConnection()`.\n- `GOOGLE_CLOUD_CPP_DATA_POLICY_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigquerydatapolicy.googleapis.com\") used by `MakeDataPolicyServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_DATA_TRANSFER_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigquerydatatransfer.googleapis.com\") used by `MakeDataTransferServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_METASTORE_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"biglake.googleapis.com\") used by `MakeMetastoreServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_MIGRATION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigquerymigration.googleapis.com\") used by `MakeMigrationServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_RESERVATION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"bigqueryreservation.googleapis.com\") used by `MakeReservationServiceConnection()`.\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."]]
