2.8

Changes since v2.7:

• sharding_strategy of the components::Redis now supports RedisStandalone configuration, that may be useful for tests or unimportant caches. Many thanks to Aleksey Ignatiev for the PR!

• kafka::Producer now has the API for sending Kafka headers. Many thanks to Mikhail Romaneev for the PR and to Fedor Lobanov for the fix!

• kafka::ConsumerScope now has the API for receiving Kafka headers.

• Add span events to OpenTelemetry via tracing::Span::AddEvent(). Many thanks to Dudnik Pavel for the PR.

• Added logging::JsonString to explicitly describe in type system that a string contains loggable JSON. Many thanks to akhoroshev for the PR!

• Deadline Propagation for PostgreSQL is now enabled by default and can be controlled via deadline-propagation-enabled static option of the components::Postgres.

• Testsuite now supports @pytest.mark.uservice_oneshot.

• utils::regex now always uses a faster and safer Re2 instead of boost::regex.

• Dynamic config USERVER_HANDLER_STREAM_API_ENABLED is not used any more.

• server::handlers::HttpHandlerStatic now has an expires static config option.

• kafka::ProducerComponent and kafka::ConsumerComponent now supprt 'SASL_PLAINTEXT' security protocol. Many thanks to Mikhail Romaneev for the PR!

• Implemented OneOf discriminator mapping to integer and generation of fmt::formatter for enums in chaotic.

• kRoundRobin load distribution in PostgreSQL is now uniform

• gRPC

  • Retries are now supported and controlled via dynamic config. See ugrpc::client::Qos for more info.
  • Clients and servers now use the same configuration approach for middlewares, allowing granular overrides of settings.

• Optimizations

  • Postgres driver now uses moodycamel queue instead of boost::lockfree. Up to 2 times faster retrieval of connection from pool.
  • utils::TrivialBiMap is used in more cases, leading to faster runtime search and minor decrease in binaries size.
  • Multiple std::string constants were replaced with constinit types, leading to faster startup times and smaller binaries.
  • Avoid URL copies in clients::http::Request

• Documentation and Diagnostics:

  • Fixed typo at Build dependencies. Many thanks to Konstantin Goncharik for the PR.
  • More docs on External SQL/YQL files
  • Improved parse failure messages for Dynamic config
  • Improved diagnostics for corrupted tracing::Span
  • Erroneous attempt to log function address is now captured at build time.

• Build

  • Debug symbols of userver libraries are now compressed with zstd if the toolset supports it, leading to smaller binaries size.
  • Docker images now use zstd compression too.
  • Dropped CI testing on Ubuntu 20.04 which lifetime almost ended.
  • Improved build type matching for installed userver. Many thanks to Aleksey Ignatiev for the PR!