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_DATA_CATALOG_ENDPOINT=... overrides the EndpointOption (which defaults to "datacatalog.googleapis.com") used by MakeDataCatalogConnection().
GOOGLE_CLOUD_CPP_LINEAGE_ENDPOINT=... overrides the EndpointOption (which defaults to "datalineage.googleapis.com") used by MakeLineageConnection().
GOOGLE_CLOUD_CPP_POLICY_TAG_MANAGER_ENDPOINT=... overrides the EndpointOption (which defaults to "datacatalog.googleapis.com") used by MakePolicyTagManagerConnection().
GOOGLE_CLOUD_CPP_POLICY_TAG_MANAGER_SERIALIZATION_ENDPOINT=... overrides the EndpointOption (which defaults to "datacatalog.googleapis.com") used by MakePolicyTagManagerSerializationConnection().
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::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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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."],[[["The latest version of the Data Catalog C++ library is 2.37.0-rc, and the page provides links to documentation for versions ranging from 2.11.0 to 2.37.0-rc."],["Environment variables such as `GOOGLE_CLOUD_CPP_DATA_CATALOG_ENDPOINT`, `GOOGLE_CLOUD_CPP_LINEAGE_ENDPOINT`, and others can be used to override default endpoints for different components."],["Tracing for gRPC calls can be enabled using `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, and this should be used in tandem with setting `GOOGLE_CLOUD_CPP_ENABLE_CLOG` to see output to console."],["The `GOOGLE_CLOUD_PROJECT` environment variable is utilized in examples and integration tests, but it does not affect the behavior of the library itself."],["Logging in the library can be turned on by setting the `GOOGLE_CLOUD_CPP_ENABLE_CLOG` environment variable, which provides a backend for the library's logging infrastructure to print to console."]]],[]]
