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::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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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."],[[["The latest release candidate version for the Data Catalog is 2.37.0-rc, with numerous previous versions available, ranging down to version 2.11.0."],["Environment variables like `GOOGLE_CLOUD_CPP_DATA_CATALOG_ENDPOINT`, `GOOGLE_CLOUD_CPP_LINEAGE_ENDPOINT`, `GOOGLE_CLOUD_CPP_POLICY_TAG_MANAGER_ENDPOINT`, and `GOOGLE_CLOUD_CPP_POLICY_TAG_MANAGER_SERIALIZATION_ENDPOINT` can override the default endpoints used by various Data Catalog functions."],["Tracing for gRPC calls can be enabled by setting `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, and detailed tracing behavior can be customized with `GOOGLE_CLOUD_CPP_TRACING_OPTIONS`."],["Logging can be turned on in the library by setting the `GOOGLE_CLOUD_CPP_ENABLE_CLOG` environment variable, so that the program can have an output on its console."],["There are ways to set a default project through a variable, but setting `GOOGLE_CLOUD_PROJECT` will not have an effect on the library itself."]]],[]]
