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_TRACE_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "cloudtrace.googleapis.com") used byMakeTraceServiceConnection().
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 document provides a comprehensive list of available versions for the C++ trace library, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc, and each version is linked to its corresponding documentation.\u003c/p\u003e\n"],["\u003cp\u003eThe library's behavior can be configured using several environment variables, offering flexibility for troubleshooting and customization.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACE_SERVICE_ENDPOINT\u003c/code\u003e environment variable allows overriding the default endpoint for the trace service, providing control over the service's location.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, which logs each gRPC request and response and requires setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e to display the output on the console.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e environment variable can be utilized to change the way gRPC tracing is displayed, including output format and string/byte field truncation.\u003c/p\u003e\n"]]],[],null,["Version 2.17.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/trace/latest/trace-env)\n- [2.41.0](/cpp/docs/reference/trace/2.41.0/trace-env)\n- [2.40.0](/cpp/docs/reference/trace/2.40.0/trace-env)\n- [2.39.0](/cpp/docs/reference/trace/2.39.0/trace-env)\n- [2.38.0](/cpp/docs/reference/trace/2.38.0/trace-env)\n- [2.37.0](/cpp/docs/reference/trace/2.37.0/trace-env)\n- [2.36.0](/cpp/docs/reference/trace/2.36.0/trace-env)\n- [2.35.0](/cpp/docs/reference/trace/2.35.0/trace-env)\n- [2.34.0](/cpp/docs/reference/trace/2.34.0/trace-env)\n- [2.33.0](/cpp/docs/reference/trace/2.33.0/trace-env)\n- [2.32.0](/cpp/docs/reference/trace/2.32.0/trace-env)\n- [2.31.0](/cpp/docs/reference/trace/2.31.0/trace-env)\n- [2.30.0](/cpp/docs/reference/trace/2.30.0/trace-env)\n- [2.29.0](/cpp/docs/reference/trace/2.29.0/trace-env)\n- [2.28.0](/cpp/docs/reference/trace/2.28.0/trace-env)\n- [2.27.0](/cpp/docs/reference/trace/2.27.0/trace-env)\n- [2.26.0](/cpp/docs/reference/trace/2.26.0/trace-env)\n- [2.25.1](/cpp/docs/reference/trace/2.25.1/trace-env)\n- [2.24.0](/cpp/docs/reference/trace/2.24.0/trace-env)\n- [2.23.0](/cpp/docs/reference/trace/2.23.0/trace-env)\n- [2.22.1](/cpp/docs/reference/trace/2.22.1/trace-env)\n- [2.21.0](/cpp/docs/reference/trace/2.21.0/trace-env)\n- [2.20.0](/cpp/docs/reference/trace/2.20.0/trace-env)\n- [2.19.0](/cpp/docs/reference/trace/2.19.0/trace-env)\n- [2.18.0](/cpp/docs/reference/trace/2.18.0/trace-env)\n- [2.17.0](/cpp/docs/reference/trace/2.17.0/trace-env)\n- [2.16.0](/cpp/docs/reference/trace/2.16.0/trace-env)\n- [2.15.1](/cpp/docs/reference/trace/2.15.1/trace-env)\n- [2.14.0](/cpp/docs/reference/trace/2.14.0/trace-env)\n- [2.13.0](/cpp/docs/reference/trace/2.13.0/trace-env)\n- [2.12.0](/cpp/docs/reference/trace/2.12.0/trace-env)\n- [2.11.0](/cpp/docs/reference/trace/2.11.0/trace-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_TRACE_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"cloudtrace.googleapis.com\") used by `MakeTraceServiceConnection()`.\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."]]
