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
PUBSUB_EMULATOR_HOST=host:port: tells the library to connect to the specified emulator rather than the default endpoint. Intended for testing only.
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 2025-03-05 UTC."],[[["The latest version of the Pub/Sub C++ library is 2.37.0-rc, with a list of previous versions ranging from 2.36.0 down to 2.11.0 available for reference."],["Environment variables can be utilized to adjust the library's behavior, particularly for debugging purposes, with functions also available for configuring the library within code."],["The `PUBSUB_EMULATOR_HOST` environment variable allows the library to connect to a specific emulator for testing instead of the default endpoint."],["Tracing for gRPC calls can be enabled using the `GOOGLE_CLOUD_CPP_ENABLE_TRACING` variable, and the `GOOGLE_CLOUD_CPP_ENABLE_CLOG` variable is necessary to see the tracing output on the console."],["The `GOOGLE_CLOUD_CPP_TRACING_OPTIONS` variable can modify gRPC tracing output characteristics, such as formatting and field truncation, and the `GOOGLE_CLOUD_CPP_ENABLE_CLOG` will turn on the logging in the library."]]],[]]
