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_TPU_ENDPOINT=... overrides the EndpointOption (which defaults to "tpu.googleapis.com") used by MakeTpuConnection().
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"]],[["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 2025-03-14 UTC."],[[["This page provides documentation for various versions of the C++ TPU library, ranging from version 2.11.0 up to the release candidate 2.37.0-rc."],["Environment variables, such as `GOOGLE_CLOUD_CPP_TPU_ENDPOINT`, `GOOGLE_CLOUD_CPP_ENABLE_TRACING`, and `GOOGLE_CLOUD_CPP_ENABLE_CLOG`, can be used to configure and troubleshoot the library's behavior, including endpoint overrides and logging."],["Setting `GOOGLE_CLOUD_PROJECT` will only affect examples and integration tests, and will have no effect on the library."],["The library offers gRPC call tracing by setting `GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`, which can be further configured with the `GOOGLE_CLOUD_CPP_TRACING_OPTIONS` environment variable."]]],[]]
