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_DATASTORE_ADMIN_ENDPOINT=...overrides theEndpointOption(which defaults to "datastore.googleapis.com") used byMakeDatastoreAdminConnection().
GOOGLE_CLOUD_CPP_DATASTORE_ENDPOINT=...overrides theEndpointOption(which defaults to "datastore.googleapis.com") used byMakeDatastoreConnection().
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 details environment variables and functions for configuring the behavior of the DataStore C++ library, useful for troubleshooting and customization.\u003c/p\u003e\n"],["\u003cp\u003eThe latest release of the DataStore C++ library is version 2.37.0-rc, with a list of older versions available, dating back to 2.15.1, each with a link to its respective documentation.\u003c/p\u003e\n"],["\u003cp\u003eEndpoint overrides for Datastore Admin and regular Datastore connections can be set via the \u003ccode\u003eGOOGLE_CLOUD_CPP_DATASTORE_ADMIN_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_DATASTORE_ENDPOINT\u003c/code\u003e environment variables, respectively.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled using \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and logging output to the console is enabled with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eWhile the \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e variable is used in examples and tests, it does not directly affect the library's operation.\u003c/p\u003e\n"]]],[],null,["Version 2.16.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/datastore/latest/datastore-env)\n- [2.41.0](/cpp/docs/reference/datastore/2.41.0/datastore-env)\n- [2.40.0](/cpp/docs/reference/datastore/2.40.0/datastore-env)\n- [2.39.0](/cpp/docs/reference/datastore/2.39.0/datastore-env)\n- [2.38.0](/cpp/docs/reference/datastore/2.38.0/datastore-env)\n- [2.37.0](/cpp/docs/reference/datastore/2.37.0/datastore-env)\n- [2.36.0](/cpp/docs/reference/datastore/2.36.0/datastore-env)\n- [2.35.0](/cpp/docs/reference/datastore/2.35.0/datastore-env)\n- [2.34.0](/cpp/docs/reference/datastore/2.34.0/datastore-env)\n- [2.33.0](/cpp/docs/reference/datastore/2.33.0/datastore-env)\n- [2.32.0](/cpp/docs/reference/datastore/2.32.0/datastore-env)\n- [2.31.0](/cpp/docs/reference/datastore/2.31.0/datastore-env)\n- [2.30.0](/cpp/docs/reference/datastore/2.30.0/datastore-env)\n- [2.29.0](/cpp/docs/reference/datastore/2.29.0/datastore-env)\n- [2.28.0](/cpp/docs/reference/datastore/2.28.0/datastore-env)\n- [2.27.0](/cpp/docs/reference/datastore/2.27.0/datastore-env)\n- [2.26.0](/cpp/docs/reference/datastore/2.26.0/datastore-env)\n- [2.25.1](/cpp/docs/reference/datastore/2.25.1/datastore-env)\n- [2.24.0](/cpp/docs/reference/datastore/2.24.0/datastore-env)\n- [2.23.0](/cpp/docs/reference/datastore/2.23.0/datastore-env)\n- [2.22.1](/cpp/docs/reference/datastore/2.22.1/datastore-env)\n- [2.21.0](/cpp/docs/reference/datastore/2.21.0/datastore-env)\n- [2.20.0](/cpp/docs/reference/datastore/2.20.0/datastore-env)\n- [2.19.0](/cpp/docs/reference/datastore/2.19.0/datastore-env)\n- [2.18.0](/cpp/docs/reference/datastore/2.18.0/datastore-env)\n- [2.17.0](/cpp/docs/reference/datastore/2.17.0/datastore-env)\n- [2.16.0](/cpp/docs/reference/datastore/2.16.0/datastore-env)\n- [2.15.1](/cpp/docs/reference/datastore/2.15.1/datastore-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_DATASTORE_ADMIN_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"datastore.googleapis.com\") used by `MakeDatastoreAdminConnection()`.\n- `GOOGLE_CLOUD_CPP_DATASTORE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"datastore.googleapis.com\") used by `MakeDatastoreConnection()`.\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."]]
