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_DATASTREAM_ENDPOINT=...overrides theEndpointOption(which defaults to "datastream.googleapis.com") used byMakeDatastreamConnection().
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\u003eThis page provides documentation for various versions of the Datastream C++ library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables such as \u003ccode\u003eGOOGLE_CLOUD_CPP_DATASTREAM_ENDPOINT\u003c/code\u003e can be used to customize the behavior of the library, like overriding the default endpoint for the Datastream connection.\u003c/p\u003e\n"],["\u003cp\u003eTracing and logging capabilities in the library can be enabled and configured through environment variables like \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e environment variable can be set to specify a default Google Cloud project for examples and tests, although it does not impact the core library functionality.\u003c/p\u003e\n"],["\u003cp\u003eSeveral pages are provided to give more context regarding the available configurations with the library, such as links for \u003ccode\u003eEndpointOption\u003c/code\u003e, \u003ccode\u003eTracingComponentsOption\u003c/code\u003e, \u003ccode\u003eGrpcTracingOptionsOption\u003c/code\u003e, \u003ccode\u003eLogBackend\u003c/code\u003e and \u003ccode\u003eLogSink\u003c/code\u003e.\u003c/p\u003e\n"]]],[],null,["Version 2.21.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/datastream/latest/datastream-env)\n- [2.41.0](/cpp/docs/reference/datastream/2.41.0/datastream-env)\n- [2.40.0](/cpp/docs/reference/datastream/2.40.0/datastream-env)\n- [2.39.0](/cpp/docs/reference/datastream/2.39.0/datastream-env)\n- [2.38.0](/cpp/docs/reference/datastream/2.38.0/datastream-env)\n- [2.37.0](/cpp/docs/reference/datastream/2.37.0/datastream-env)\n- [2.36.0](/cpp/docs/reference/datastream/2.36.0/datastream-env)\n- [2.35.0](/cpp/docs/reference/datastream/2.35.0/datastream-env)\n- [2.34.0](/cpp/docs/reference/datastream/2.34.0/datastream-env)\n- [2.33.0](/cpp/docs/reference/datastream/2.33.0/datastream-env)\n- [2.32.0](/cpp/docs/reference/datastream/2.32.0/datastream-env)\n- [2.31.0](/cpp/docs/reference/datastream/2.31.0/datastream-env)\n- [2.30.0](/cpp/docs/reference/datastream/2.30.0/datastream-env)\n- [2.29.0](/cpp/docs/reference/datastream/2.29.0/datastream-env)\n- [2.28.0](/cpp/docs/reference/datastream/2.28.0/datastream-env)\n- [2.27.0](/cpp/docs/reference/datastream/2.27.0/datastream-env)\n- [2.26.0](/cpp/docs/reference/datastream/2.26.0/datastream-env)\n- [2.25.1](/cpp/docs/reference/datastream/2.25.1/datastream-env)\n- [2.24.0](/cpp/docs/reference/datastream/2.24.0/datastream-env)\n- [2.23.0](/cpp/docs/reference/datastream/2.23.0/datastream-env)\n- [2.22.1](/cpp/docs/reference/datastream/2.22.1/datastream-env)\n- [2.21.0](/cpp/docs/reference/datastream/2.21.0/datastream-env)\n- [2.20.0](/cpp/docs/reference/datastream/2.20.0/datastream-env)\n- [2.19.0](/cpp/docs/reference/datastream/2.19.0/datastream-env)\n- [2.18.0](/cpp/docs/reference/datastream/2.18.0/datastream-env)\n- [2.17.0](/cpp/docs/reference/datastream/2.17.0/datastream-env)\n- [2.16.0](/cpp/docs/reference/datastream/2.16.0/datastream-env)\n- [2.15.1](/cpp/docs/reference/datastream/2.15.1/datastream-env)\n- [2.14.0](/cpp/docs/reference/datastream/2.14.0/datastream-env)\n- [2.13.0](/cpp/docs/reference/datastream/2.13.0/datastream-env)\n- [2.12.0](/cpp/docs/reference/datastream/2.12.0/datastream-env)\n- [2.11.0](/cpp/docs/reference/datastream/2.11.0/datastream-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_DATASTREAM_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"datastream.googleapis.com\") used by `MakeDatastreamConnection()`.\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`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1TracingComponentsOption.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."]]
