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_MIGRATION_CENTER_ENDPOINT=...overrides theEndpointOption(which defaults to "migrationcenter.googleapis.com") used byMakeMigrationCenterConnection().
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::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"]],[["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\u003eThe latest version available is 2.37.0-rc, with numerous other versions also documented, ranging down to version 2.13.0.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables can be utilized to adjust the library's operation, particularly useful for troubleshooting, in addition to having configurable options in the code.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_CPP_MIGRATION_CENTER_ENDPOINT\u003c/code\u003e is an environment variable that can be used to override the default endpoint for \u003ccode\u003eMakeMigrationCenterConnection()\u003c/code\u003e.\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 logs can be output to the console if \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e is also set.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e can set the default project for examples and integration tests, however does not have any effect in the library.\u003c/p\u003e\n"]]],[],null,["Version 2.23.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/migrationcenter/latest/migrationcenter-env)\n- [2.41.0](/cpp/docs/reference/migrationcenter/2.41.0/migrationcenter-env)\n- [2.40.0](/cpp/docs/reference/migrationcenter/2.40.0/migrationcenter-env)\n- [2.39.0](/cpp/docs/reference/migrationcenter/2.39.0/migrationcenter-env)\n- [2.38.0](/cpp/docs/reference/migrationcenter/2.38.0/migrationcenter-env)\n- [2.37.0](/cpp/docs/reference/migrationcenter/2.37.0/migrationcenter-env)\n- [2.36.0](/cpp/docs/reference/migrationcenter/2.36.0/migrationcenter-env)\n- [2.35.0](/cpp/docs/reference/migrationcenter/2.35.0/migrationcenter-env)\n- [2.34.0](/cpp/docs/reference/migrationcenter/2.34.0/migrationcenter-env)\n- [2.33.0](/cpp/docs/reference/migrationcenter/2.33.0/migrationcenter-env)\n- [2.32.0](/cpp/docs/reference/migrationcenter/2.32.0/migrationcenter-env)\n- [2.31.0](/cpp/docs/reference/migrationcenter/2.31.0/migrationcenter-env)\n- [2.30.0](/cpp/docs/reference/migrationcenter/2.30.0/migrationcenter-env)\n- [2.29.0](/cpp/docs/reference/migrationcenter/2.29.0/migrationcenter-env)\n- [2.28.0](/cpp/docs/reference/migrationcenter/2.28.0/migrationcenter-env)\n- [2.27.0](/cpp/docs/reference/migrationcenter/2.27.0/migrationcenter-env)\n- [2.26.0](/cpp/docs/reference/migrationcenter/2.26.0/migrationcenter-env)\n- [2.25.1](/cpp/docs/reference/migrationcenter/2.25.1/migrationcenter-env)\n- [2.24.0](/cpp/docs/reference/migrationcenter/2.24.0/migrationcenter-env)\n- [2.23.0](/cpp/docs/reference/migrationcenter/2.23.0/migrationcenter-env)\n- [2.22.1](/cpp/docs/reference/migrationcenter/2.22.1/migrationcenter-env)\n- [2.21.0](/cpp/docs/reference/migrationcenter/2.21.0/migrationcenter-env)\n- [2.20.0](/cpp/docs/reference/migrationcenter/2.20.0/migrationcenter-env)\n- [2.19.0](/cpp/docs/reference/migrationcenter/2.19.0/migrationcenter-env)\n- [2.18.0](/cpp/docs/reference/migrationcenter/2.18.0/migrationcenter-env)\n- [2.17.0](/cpp/docs/reference/migrationcenter/2.17.0/migrationcenter-env)\n- [2.16.0](/cpp/docs/reference/migrationcenter/2.16.0/migrationcenter-env)\n- [2.15.1](/cpp/docs/reference/migrationcenter/2.15.1/migrationcenter-env)\n- [2.14.0](/cpp/docs/reference/migrationcenter/2.14.0/migrationcenter-env)\n- [2.13.0](/cpp/docs/reference/migrationcenter/2.13.0/migrationcenter-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_MIGRATION_CENTER_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"migrationcenter.googleapis.com\") used by `MakeMigrationCenterConnection()`.\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::TracingComponentsOption`](about:invalid#zCSafez)`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."]]
