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 page provides documentation for various versions of the storage control library, ranging from version 2.21.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables, such as \u003ccode\u003eGOOGLE_CLOUD_CPP_STORAGE_CONTROL_ENDPOINT\u003c/code\u003e, can be used to override default configurations like the endpoint used by \u003ccode\u003eMakeStorageControlConnection()\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 its behavior can be further customized with \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe environment variable \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e allows for logging within the library, enabling the ability to display log information.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e environment variable is used in examples and integration tests to set the GCP project, but does not impact library behavior.\u003c/p\u003e\n"]]],[],null,["Version 2.30.0keyboard_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."]]
