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_STORAGE_CONTROL_ENDPOINT=...overrides theEndpointOption(which defaults to "storage.googleapis.com") used byMakeStorageControlConnection().
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 document provides reference information for configuring the behavior of the storage control library, with version 2.29.0 being the latest fully released version and version 2.37.0-rc as the most recent release candidate.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables such as \u003ccode\u003eGOOGLE_CLOUD_CPP_STORAGE_CONTROL_ENDPOINT\u003c/code\u003e, \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e, and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e can be utilized to customize the library's operation, including endpoint overrides and logging capabilities.\u003c/p\u003e\n"],["\u003cp\u003eThe library supports gRPC tracing, which can be activated via \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e, and further customized using the \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e environment variable to modify how tracing data is displayed.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e variable is used for testing purposes in examples and integration tests but has no impact on the library's functionality.\u003c/p\u003e\n"],["\u003cp\u003eLogging can be enabled within the library by setting the \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e environment variable to "yes", which allows log output to be printed to the program's console, especially in the absence of a custom logging backend.\u003c/p\u003e\n"]]],[],null,["Version 2.29.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/storagecontrol/latest/storagecontrol-env)\n- [2.41.0](/cpp/docs/reference/storagecontrol/2.41.0/storagecontrol-env)\n- [2.40.0](/cpp/docs/reference/storagecontrol/2.40.0/storagecontrol-env)\n- [2.39.0](/cpp/docs/reference/storagecontrol/2.39.0/storagecontrol-env)\n- [2.38.0](/cpp/docs/reference/storagecontrol/2.38.0/storagecontrol-env)\n- [2.37.0](/cpp/docs/reference/storagecontrol/2.37.0/storagecontrol-env)\n- [2.36.0](/cpp/docs/reference/storagecontrol/2.36.0/storagecontrol-env)\n- [2.35.0](/cpp/docs/reference/storagecontrol/2.35.0/storagecontrol-env)\n- [2.34.0](/cpp/docs/reference/storagecontrol/2.34.0/storagecontrol-env)\n- [2.33.0](/cpp/docs/reference/storagecontrol/2.33.0/storagecontrol-env)\n- [2.32.0](/cpp/docs/reference/storagecontrol/2.32.0/storagecontrol-env)\n- [2.31.0](/cpp/docs/reference/storagecontrol/2.31.0/storagecontrol-env)\n- [2.30.0](/cpp/docs/reference/storagecontrol/2.30.0/storagecontrol-env)\n- [2.29.0](/cpp/docs/reference/storagecontrol/2.29.0/storagecontrol-env)\n- [2.28.0](/cpp/docs/reference/storagecontrol/2.28.0/storagecontrol-env)\n- [2.27.0](/cpp/docs/reference/storagecontrol/2.27.0/storagecontrol-env)\n- [2.26.0](/cpp/docs/reference/storagecontrol/2.26.0/storagecontrol-env)\n- [2.25.1](/cpp/docs/reference/storagecontrol/2.25.1/storagecontrol-env)\n- [2.24.0](/cpp/docs/reference/storagecontrol/2.24.0/storagecontrol-env)\n- [2.23.0](/cpp/docs/reference/storagecontrol/2.23.0/storagecontrol-env)\n- [2.22.1](/cpp/docs/reference/storagecontrol/2.22.1/storagecontrol-env)\n- [2.21.0](/cpp/docs/reference/storagecontrol/2.21.0/storagecontrol-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_STORAGE_CONTROL_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"storage.googleapis.com\") used by `MakeStorageControlConnection()`.\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."]]
