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 the EndpointOption (which defaults to "logging.googleapis.com") used by MakeConfigServiceV2Connection().
GOOGLE_CLOUD_CPP_LOGGING_SERVICE_V2_ENDPOINT=... overrides the EndpointOption (which defaults to "logging.googleapis.com") used by MakeLoggingServiceV2Connection().
GOOGLE_CLOUD_CPP_METRICS_SERVICE_V2_ENDPOINT=... overrides the EndpointOption (which defaults to "logging.googleapis.com") used by MakeMetricsServiceV2Connection().
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.
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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 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,[]]
