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_FLEET_ROUTING_ENDPOINT=... overrides the EndpointOption (which defaults to "cloudoptimization.googleapis.com") used by MakeFleetRoutingConnection().
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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14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 provides an overview of various versions of a C++ library, ranging from version 2.11.0 up to the release candidate 2.37.0-rc, with links to specific optimization environment configurations for each version.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables can be utilized to fine-tune the library's functionality and behavior, offering convenient troubleshooting options.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_CPP_FLEET_ROUTING_ENDPOINT\u003c/code\u003e enables users to override the default endpoint used by \u003ccode\u003eMakeFleetRoutingConnection()\u003c/code\u003e, providing flexibility in managing connection destinations.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be activated with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e can be used to manage output to the console.\u003c/p\u003e\n"],["\u003cp\u003eWhile \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e is used in examples and integration tests to set the GCP project, it does not affect the library's behavior.\u003c/p\u003e\n"]]],[],null,[]]
