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 the latest release candidate being version 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe library's behavior, especially when troubleshooting, can be configured using environment variables like \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 to override default endpoint settings.\u003c/p\u003e\n"],["\u003cp\u003eEnabling tracing for gRPC calls can be achieved by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and outputting the tracing data requires also setting the \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e environment variable.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e variable allows for customization of gRPC tracing output, like string/bytes truncation, while \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e activates logging by providing a backend to print the data.\u003c/p\u003e\n"],["\u003cp\u003eA list of available library versions, dating back to 2.11.0, is available, and the \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e variable can be used for examples and integration tests, but has no effect on the library itself.\u003c/p\u003e\n"]]],[],null,["Version 2.28.0keyboard_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."]]
