v1.12.0 release

Release of core packages

• opentelemetry-api
• opentelemetry-sdk

and exporter packages:

• opentelemetry-exporter-otlp (gRPC + HTTP/JSON)
• opentelemetry-exporter-prometheus

What's Changed

• [BUILD] Support pkg-config by @dbolduc in https://github.com/open-telemetry/opentelemetry-cpp/pull/2269
• [CI] Do not automatically close stale issues by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2277
• [CI] Benchmark workflow fails, C++14 required to build grpc by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2278
• [SDK] Increase metric name maximum length from 63 to 255 characters by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2284
• [SEMANTIC CONVENTION] Deprecated semconv (in the spec) not deprecated (in C++) by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2285
• [SDK] Remove unused member variables from SyncMetricStorage by @lalitb in https://github.com/open-telemetry/opentelemetry-cpp/pull/2294
• Bump actions/checkout from 3 to 4 by @dependabot in https://github.com/open-telemetry/opentelemetry-cpp/pull/2295
• [DEPRECATION] Deprecate ZPAGES by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2291
• Bump docker/setup-qemu-action from 2 to 3 by @dependabot in https://github.com/open-telemetry/opentelemetry-cpp/pull/2306
• Bump docker/build-push-action from 4 to 5 by @dependabot in https://github.com/open-telemetry/opentelemetry-cpp/pull/2308
• Bump docker/setup-buildx-action from 2 to 3 by @dependabot in https://github.com/open-telemetry/opentelemetry-cpp/pull/2307
• [API] Deliver ABI breaking changes by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2222
• [SDK] Allow metric instrument names to contain / characters by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2310
• Bump codecov/codecov-action from 3 to 4 by @dependabot in https://github.com/open-telemetry/opentelemetry-cpp/pull/2314
• Revert "Bump codecov/codecov-action from 3 to 4" by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2315
• [SDK] Fix Observable Counters/UpDownCounters by @lalitb in https://github.com/open-telemetry/opentelemetry-cpp/pull/2298
• [SDK] Add exemplar reservoir to async metric storage by @ThomsonTan in https://github.com/open-telemetry/opentelemetry-cpp/pull/2319
• [TEST] Fix lifetime issues in prometheus test utils by @punya in https://github.com/open-telemetry/opentelemetry-cpp/pull/2322
• [EXPORTER] Prometheus: Remove explicit timestamps from metric points by @punya in https://github.com/open-telemetry/opentelemetry-cpp/pull/2324
• [EXPORTER] Prometheus: Handle attribute key collisions from sanitation by @punya in https://github.com/open-telemetry/opentelemetry-cpp/pull/2326
• [EXPORTER] Prometheus cleanup, test with TranslateToPrometheus by @punya in https://github.com/open-telemetry/opentelemetry-cpp/pull/2329
• [SDK] Fix log message in Meter::RegisterSyncMetricStorage by @ThomsonTan in https://github.com/open-telemetry/opentelemetry-cpp/pull/2325
• [DOC] Simplify the project status section by @reyang in https://github.com/open-telemetry/opentelemetry-cpp/pull/2332
• [EXPORTER] Prometheus: Sanitize labels according to spec by @punya in https://github.com/open-telemetry/opentelemetry-cpp/pull/2330
• [SDK] Fix deadlock when shuting down http client by @owent in https://github.com/open-telemetry/opentelemetry-cpp/pull/2337
• [Exporter] Group spans by resource and instrumentation scope in OTLP export requests by @mbrobbel in https://github.com/open-telemetry/opentelemetry-cpp/pull/2335
• [BUILD] Need fine-grained HAVE_CPP_STDLIB by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2304
• [API] Add InstrumentationScope attributes in MeterProvider::GetMeter() by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2224
• [REMOVAL] Drop C++11 support by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2342
• [EXPORTER] prometheus: add otel_scope_name and otel_scope_version labels by @dashpole in https://github.com/open-telemetry/opentelemetry-cpp/pull/2293
• [EXPORTER] Export resource for prometheus by @owent in https://github.com/open-telemetry/opentelemetry-cpp/pull/2301
• [BUILD] error: read-only reference ‘value’ used as ‘asm’ output by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2354
• [BUILD] Build break with external CMake nlohman_json package by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2353
• [BUILD] Upgrade libcurl to version 8.4.0 by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2358
• [BUILD] Fix opentracing-shim when added in super project by @andremarianiello in https://github.com/open-telemetry/opentelemetry-cpp/pull/2356
• [BUILD] Fix protoc searching with non-imported protobuf::protoc target by @owent in https://github.com/open-telemetry/opentelemetry-cpp/pull/2362
• [BUILD] Support to use different cmake package CONFIG of dependencies. by @owent in https://github.com/open-telemetry/opentelemetry-cpp/pull/2263
• [SEMANTIC CONVENTION] Upgrade to semconv 1.22.0 by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2368
• [RELEASE] Prepare release 1.12.0 by @marcalff in https://github.com/open-telemetry/opentelemetry-cpp/pull/2359

Important changes

• [API] Add InstrumentationScope attributes in MeterProvider::GetMeter() #2224
  • MeterProvider::GetMeter() now accepts InstrumentationScope attributes.
  • Because this is an ABI breaking change, the fix is only available with the CMake option WITH_ABI_VERSION_2=ON.
  • When building with CMake option WITH_ABI_VERSION_1=ON (by default) the ABI is unchanged, and the fix is not available.

Breaking changes

• [BUILD] Need fine-grained HAVE_CPP_STDLIB #2304

  • In CMAKE, the boolean option WITH_STL as changed to an option that accepts the values OFF, ON, CXX11, CXX14, CXX17, CXX20 and CXX23.
  • Applications makefiles that did not set WITH_STL need to use WITH_STL=OFF instead (this is the default).
  • Applications makefiles that did set WITH_STL need to use WITH_STL=ON instead, or may choose to pick a specific value.
  • In the API header files, the preprocessor symbol HAVE_CPP_STDLIB is no longer used.
  • Applications that did set HAVE_CPP_STDLIB before, need to set OPENTELEMETRY_STL_VERSION=<version> instead, to build with a specific STL version (2011, 2014, 2017, 2020, 2023).
  • The opentelemetry-cpp makefile no longer sets CMAKE_CXX_STANDARD by itself. Instead, the CMAKE_CXX_STANDARD and/or compiler options -stdc++ used by the caller are honored.
  • Applications that set neither CMAKE_CXX_STANDARD nor -stdc++ options may need to provide a C++ standard in their makefiles.

• [REMOVAL] Drop C++11 support #2342

  • Building with C++11 is no longer supported.

New Contributors

• @punya made their first contribution in https://github.com/open-telemetry/opentelemetry-cpp/pull/2322
• @dashpole made their first contribution in https://github.com/open-telemetry/opentelemetry-cpp/pull/2293
• @andremarianiello made their first contribution in https://github.com/open-telemetry/opentelemetry-cpp/pull/2356

Full Changelog: https://github.com/open-telemetry/opentelemetry-cpp/compare/v1.11.0...v1.12.0