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_QUOTA_CONTROLLER_ENDPOINT=... overrides the EndpointOption (which defaults to "servicecontrol.googleapis.com") used by MakeQuotaControllerConnection().
GOOGLE_CLOUD_CPP_SERVICE_CONTROLLER_ENDPOINT=... overrides the EndpointOption (which defaults to "servicecontrol.googleapis.com") used by MakeServiceControllerConnection().
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::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"]],[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 document provides reference information for the \u003ccode\u003eservicecontrol-env\u003c/code\u003e across multiple versions, starting with the latest release candidate \u003ccode\u003e2.37.0-rc\u003c/code\u003e and spanning down to version \u003ccode\u003e2.11.0\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables such as \u003ccode\u003eGOOGLE_CLOUD_CPP_QUOTA_CONTROLLER_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_SERVICE_CONTROLLER_ENDPOINT\u003c/code\u003e can be used to override the default endpoint used by the \u003ccode\u003eMakeQuotaControllerConnection()\u003c/code\u003e and \u003ccode\u003eMakeServiceControllerConnection()\u003c/code\u003e, respectively.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and it is recommended to also set \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e to produce console output unless a custom logging backend is set up.\u003c/p\u003e\n"],["\u003cp\u003eThe behavior of gRPC tracing, such as message formatting and string truncation, can be further customized using the \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e environment variable.\u003c/p\u003e\n"]]],[],null,[]]
