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."],[[["This document outlines various versions of the C++ Pub/Sub library, ranging from the latest release candidate, version 2.37.0-rc, down to version 2.11.0."],["Environment variables like `PUBSUB_EMULATOR_HOST`, `GOOGLE_CLOUD_CPP_ENABLE_TRACING`, `GOOGLE_CLOUD_CPP_TRACING_OPTIONS`, and `GOOGLE_CLOUD_CPP_ENABLE_CLOG` can be used to configure the library's behavior, including endpoint overrides, logging, and gRPC tracing."],["The `GOOGLE_CLOUD_PROJECT` environment variable is used in examples and tests to specify the GCP project but does not have an effect in the library itself."],["Tracing can be enabled for gRPC calls using the `GOOGLE_CLOUD_CPP_ENABLE_TRACING` environment variable, which can be further customized using the `GOOGLE_CLOUD_CPP_TRACING_OPTIONS` environment variable."],["Enabling the `GOOGLE_CLOUD_CPP_ENABLE_CLOG` environment variable is important to see the logs in the console from the library unless a custom logging backend is configured."]]],[]]
