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 the EndpointOption (which defaults to "datastore.googleapis.com") used by MakeDatastoreAdminConnection().
GOOGLE_CLOUD_CPP_DATASTORE_ENDPOINT=... overrides the EndpointOption (which defaults to "datastore.googleapis.com") used by MakeDatastoreConnection().
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.
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"]],[["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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 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,[]]
