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
BIGTABLE_EMULATOR_HOST=host:port: tells the library to connect to the specified emulator rather than the default endpoint. Intended for testing only.
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.
GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc-streams: turns on tracing for streaming gRPC calls, such as Table::ReadRows(). Be warned that streams produce a lot of output.
GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc,rpc-streams: turns on tracing for both regular RPC calls and streaming RPC calls.
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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis page lists the available versions of the Bigtable C++ client library, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe document details how to configure the library's behavior using environment variables, particularly for troubleshooting and testing.\u003c/p\u003e\n"],["\u003cp\u003eYou can override the default endpoint for testing using the \u003ccode\u003eBIGTABLE_EMULATOR_HOST\u003c/code\u003e environment variable, enabling connection to a specific emulator.\u003c/p\u003e\n"],["\u003cp\u003eThe environment variables \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e are available to control logging and tracing behavior, including both regular and streaming gRPC calls.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e can enable logging in the library, while \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e is used for project configuration in examples and tests, not affecting the library.\u003c/p\u003e\n"]]],[],null,["Version 2.35.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/bigtable/latest/bigtable-environment-variables)\n- [2.41.0](/cpp/docs/reference/bigtable/2.41.0/bigtable-environment-variables)\n- [2.40.0](/cpp/docs/reference/bigtable/2.40.0/bigtable-environment-variables)\n- [2.39.0](/cpp/docs/reference/bigtable/2.39.0/bigtable-environment-variables)\n- [2.38.0](/cpp/docs/reference/bigtable/2.38.0/bigtable-environment-variables)\n- [2.37.0](/cpp/docs/reference/bigtable/2.37.0/bigtable-environment-variables)\n- [2.36.0](/cpp/docs/reference/bigtable/2.36.0/bigtable-environment-variables)\n- [2.35.0](/cpp/docs/reference/bigtable/2.35.0/bigtable-environment-variables)\n- [2.34.0](/cpp/docs/reference/bigtable/2.34.0/bigtable-environment-variables)\n- [2.33.0](/cpp/docs/reference/bigtable/2.33.0/bigtable-environment-variables)\n- [2.32.0](/cpp/docs/reference/bigtable/2.32.0/bigtable-environment-variables)\n- [2.31.0](/cpp/docs/reference/bigtable/2.31.0/bigtable-environment-variables)\n- [2.30.0](/cpp/docs/reference/bigtable/2.30.0/bigtable-environment-variables)\n- [2.29.0](/cpp/docs/reference/bigtable/2.29.0/bigtable-environment-variables)\n- [2.28.0](/cpp/docs/reference/bigtable/2.28.0/bigtable-environment-variables)\n- [2.27.0](/cpp/docs/reference/bigtable/2.27.0/bigtable-environment-variables)\n- [2.26.0](/cpp/docs/reference/bigtable/2.26.0/bigtable-environment-variables)\n- [2.25.1](/cpp/docs/reference/bigtable/2.25.1/bigtable-environment-variables)\n- [2.24.0](/cpp/docs/reference/bigtable/2.24.0/bigtable-environment-variables)\n- [2.23.0](/cpp/docs/reference/bigtable/2.23.0/bigtable-environment-variables)\n- [2.22.1](/cpp/docs/reference/bigtable/2.22.1/bigtable-environment-variables)\n- [2.21.0](/cpp/docs/reference/bigtable/2.21.0/bigtable-environment-variables)\n- [2.20.0](/cpp/docs/reference/bigtable/2.20.0/bigtable-environment-variables)\n- [2.19.0](/cpp/docs/reference/bigtable/2.19.0/bigtable-environment-variables)\n- [2.18.0](/cpp/docs/reference/bigtable/2.18.0/bigtable-environment-variables)\n- [2.17.0](/cpp/docs/reference/bigtable/2.17.0/bigtable-environment-variables)\n- [2.16.0](/cpp/docs/reference/bigtable/2.16.0/bigtable-environment-variables)\n- [2.15.1](/cpp/docs/reference/bigtable/2.15.1/bigtable-environment-variables)\n- [2.14.0](/cpp/docs/reference/bigtable/2.14.0/bigtable-environment-variables)\n- [2.13.0](/cpp/docs/reference/bigtable/2.13.0/bigtable-environment-variables)\n- [2.12.0](/cpp/docs/reference/bigtable/2.12.0/bigtable-environment-variables)\n- [2.11.0](/cpp/docs/reference/bigtable/2.11.0/bigtable-environment-variables) \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`BIGTABLE_EMULATOR_HOST=host:port`: tells the library to connect to the specified emulator rather than the default endpoint. Intended for testing only.\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`GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc-streams`: turns on tracing for streaming gRPC calls, such as `Table::ReadRows()`. Be warned that streams produce a lot of output.\n\n`GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc,rpc-streams`: turns on tracing for both regular RPC calls and streaming RPC calls.\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."]]
