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_CONFIG_SERVICE_V2_ENDPOINT=...overrides theEndpointOption(which defaults to "logging.googleapis.com") used byMakeConfigServiceV2Connection().
GOOGLE_CLOUD_CPP_LOGGING_SERVICE_V2_ENDPOINT=...overrides theEndpointOption(which defaults to "logging.googleapis.com") used byMakeLoggingServiceV2Connection().
GOOGLE_CLOUD_CPP_METRICS_SERVICE_V2_ENDPOINT=...overrides theEndpointOption(which defaults to "logging.googleapis.com") used byMakeMetricsServiceV2Connection().
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::LoggingComponentsOptionGOOGLE_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 provides documentation for configuring the behavior of the C++ logging library using environment variables, with version 2.37.0-rc being the latest release.\u003c/p\u003e\n"],["\u003cp\u003eMultiple environment variables can be used to override service endpoints, such as \u003ccode\u003eGOOGLE_CLOUD_CPP_CONFIG_SERVICE_V2_ENDPOINT\u003c/code\u003e, \u003ccode\u003eGOOGLE_CLOUD_CPP_LOGGING_SERVICE_V2_ENDPOINT\u003c/code\u003e, and \u003ccode\u003eGOOGLE_CLOUD_CPP_METRICS_SERVICE_V2_ENDPOINT\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, and the behavior of this tracing can be modified with \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e enables logging within the library, allowing the logging infrastructure to print output, while \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e sets the GCP project for examples and tests but does not affect the library's functionality.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation is accessible for multiple releases going back to version 2.11.0.\u003c/p\u003e\n"]]],[],null,["Version latestkeyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/logging/latest/logging-env)\n- [2.41.0](/cpp/docs/reference/logging/2.41.0/logging-env)\n- [2.40.0](/cpp/docs/reference/logging/2.40.0/logging-env)\n- [2.39.0](/cpp/docs/reference/logging/2.39.0/logging-env)\n- [2.38.0](/cpp/docs/reference/logging/2.38.0/logging-env)\n- [2.37.0](/cpp/docs/reference/logging/2.37.0/logging-env)\n- [2.36.0](/cpp/docs/reference/logging/2.36.0/logging-env)\n- [2.35.0](/cpp/docs/reference/logging/2.35.0/logging-env)\n- [2.34.0](/cpp/docs/reference/logging/2.34.0/logging-env)\n- [2.33.0](/cpp/docs/reference/logging/2.33.0/logging-env)\n- [2.32.0](/cpp/docs/reference/logging/2.32.0/logging-env)\n- [2.31.0](/cpp/docs/reference/logging/2.31.0/logging-env)\n- [2.30.0](/cpp/docs/reference/logging/2.30.0/logging-env)\n- [2.29.0](/cpp/docs/reference/logging/2.29.0/logging-env)\n- [2.28.0](/cpp/docs/reference/logging/2.28.0/logging-env)\n- [2.27.0](/cpp/docs/reference/logging/2.27.0/logging-env)\n- [2.26.0](/cpp/docs/reference/logging/2.26.0/logging-env)\n- [2.25.1](/cpp/docs/reference/logging/2.25.1/logging-env)\n- [2.24.0](/cpp/docs/reference/logging/2.24.0/logging-env)\n- [2.23.0](/cpp/docs/reference/logging/2.23.0/logging-env)\n- [2.22.1](/cpp/docs/reference/logging/2.22.1/logging-env)\n- [2.21.0](/cpp/docs/reference/logging/2.21.0/logging-env)\n- [2.20.0](/cpp/docs/reference/logging/2.20.0/logging-env)\n- [2.19.0](/cpp/docs/reference/logging/2.19.0/logging-env)\n- [2.18.0](/cpp/docs/reference/logging/2.18.0/logging-env)\n- [2.17.0](/cpp/docs/reference/logging/2.17.0/logging-env)\n- [2.16.0](/cpp/docs/reference/logging/2.16.0/logging-env)\n- [2.15.1](/cpp/docs/reference/logging/2.15.1/logging-env)\n- [2.14.0](/cpp/docs/reference/logging/2.14.0/logging-env)\n- [2.13.0](/cpp/docs/reference/logging/2.13.0/logging-env)\n- [2.12.0](/cpp/docs/reference/logging/2.12.0/logging-env)\n- [2.11.0](/cpp/docs/reference/logging/2.11.0/logging-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_CONFIG_SERVICE_V2_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"logging.googleapis.com\") used by `MakeConfigServiceV2Connection()`.\n- `GOOGLE_CLOUD_CPP_LOGGING_SERVICE_V2_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"logging.googleapis.com\") used by `MakeLoggingServiceV2Connection()`.\n- `GOOGLE_CLOUD_CPP_METRICS_SERVICE_V2_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"logging.googleapis.com\") used by `MakeMetricsServiceV2Connection()`.\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::LoggingComponentsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1LoggingComponentsOption.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."]]
