Components

Table of Contents

• Nested Groups
• Classes
• Functions
• Detailed Description
• Function Documentation
• CommonComponentList()
• CommonServerComponentList()
• MinimalComponentList()
• MinimalServerComponentList()

Components that could be used with utils::DaemonMain like functions; see Component system for an intro. More...

Collaboration diagram for Components:

Nested Groups
	HTTP Handlers
	Handlers are components that could be used by components::Server to process the incoming requests.
	Component Default Names
	Default names of components that are used in static config files.

Classes
class	baggage::BaggageManagerComponent
	Component for relationship with header baggage. More...
class	components::CachingComponentBase< T >
	Base class for caching components. More...
class	cache::LruCacheComponent< Key, Value, Hash, Equal >
	Base class for LRU-cache components. More...
class	clients::dns::Component
	Caching DNS resolver component. More...
class	components::HttpClient
	Component that manages clients::http::Client. More...
class	components::DumpConfigurator
	Helper component that manages common configuration for userver dumps. More...
class	components::FsCache
	Component for storing files in memory. More...
class	components::HeadersPropagatorComponent
	Headers Propagator Component can scrape configured headers and then enrich HttpClient request with them. More...
class	components::LoggingConfigurator
	Helper component to configure logging. More...
class	components::ManagerControllerComponent
	Component that prepares the engine internals and starts all the other components. More...
class	components::ProcessStarter
	Component for getting the engine::subprocess::ProcessStarter. More...
class	components::SingleThreadedTaskProcessors
	Component that starts multiple single threaded task processors. More...
class	components::StatisticsStorage
	Component that keeps a utils::statistics::Storage storage for metrics. More...
class	components::TcpAcceptorBase
	Component for accepting incoming TCP connections. More...
class	components::Tracer
	Component that initializes the request tracing facilities. More...
class	congestion_control::Component
	Component to limit too active requests, also known as CC. More...
class	components::DynamicConfigClient
	Component that starts a clients::dynamic_config::Client client. More...
class	components::DynamicConfigFallbacks
	Component that setup runtime configs based on fallbacks from file. More...
class	components::DynamicConfig
	Component that stores the runtime config. More...
class	components::DynamicConfigClientUpdater
	Component that does a periodic update of runtime configs. More...
class	engine::TaskProcessorsLoadMonitor
	Component to monitor CPU usage for every TaskProcessor present in the service, and dump per-thread stats into metrics. More...
class	components::Logging
	Logging component More...
class	os_signals::ProcessorComponent
	A component for os_signals::Processor. More...
class	components::Server
	Component that listens for incoming requests, manages incoming connections and passes the requests to the appropriate handler. More...
class	components::AuthCheckerSettings
	Component that loads auth configuration settings from a components::Secdist component if the latter was registered in components::ComponentList. More...
class	server::handlers::DnsClientControl
	Handlers that controls the DNS client. More...
class	server::handlers::DynamicDebugLog
	Handler for forcing specific lines logging. Feature also known as dynamic debug logging. More...
class	server::handlers::HttpHandlerBase
	Base class for all the Userver HTTP Handlers. More...
class	server::handlers::HttpHandlerFlatbufBase< InputType, ReturnType >
	Convenient base for handlers that accept requests with body in Flatbuffer format and respond with body in Flatbuffer format. More...
class	server::handlers::HttpHandlerJsonBase
	Convenient base for handlers that accept requests with body in JSON format and respond with body in JSON format. More...
class	server::handlers::HttpHandlerStatic
	Handler that returns HTTP 200 if file exist and returns file data with mapped content/type. More...
class	server::handlers::InspectRequests
	Handler that returns information about all in-flight requests. More...
class	server::handlers::Jemalloc
	Handler that controls the jemalloc allocator. More...
class	server::handlers::LogLevel
	Handler that controls logging levels of all the loggers. More...
class	server::handlers::OnLogRotate
	Handler that controls logging levels of all the loggers. More...
class	server::handlers::Ping
	Handler that returns HTTP 200 if the service is OK and able to process requests. More...
class	server::handlers::ServerMonitor
	Handler that returns statistics data. More...
class	server::handlers::TestsControl
	Handler that allows to control the behavior of server from tests, and functional tests with testsuite in particular. More...
class	server::websocket::WebsocketHandlerBase
	Base class for WebSocket handler. More...
class	components::Secdist
	Component that stores security related data (keys, passwords, ...). More...
class	components::DefaultSecdistProvider
	Component that stores security related data (keys, passwords, ...). More...
class	components::TestsuiteSupport
	Testsuite support component. More...
class	tracing::DefaultTracingManagerLocator
	Locator component that provides access to the actual TracingManager that will be used in handlers and clients unless specified otherwise. More...
class	components::SystemStatisticsCollector
	Component for system resource usage statistics collection. More...
class	components::MongoCache< MongoCacheTraits >
	Base class for all caches polling mongo collection More...
class	components::Mongo
	MongoDB client component. More...
class	components::MultiMongo
	Dynamically configurable MongoDB client component. More...
class	storages::mongo::DistLockComponentBase
	Base class for mongo-based distlock worker components. More...
class	components::PostgreCache< PostgreCachePolicy >
	Caching component for PostgreSQL. See Caching Component for PostgreSQL. More...
class	components::Postgres
	PosgreSQL client component. More...
class	storages::postgres::DistLockComponentBase
	Base class for postgres-based distlock worker components. More...
class	components::Redis
	Redis client component. More...
class	components::ClickHouse
	ClickHouse client component. More...
class	ugrpc::client::ClientFactoryComponent
	Provides a ClientFactory in the component system. More...
class	ugrpc::client::middlewares::baggage::Component
	Component for gRPC client baggage. More...
class	ugrpc::client::middlewares::deadline_propagation::Component
	Component for gRPC client deadline_propagation. Update deadline from TaskInheritedData if it exists and more strict than context deadline. More...
class	ugrpc::client::middlewares::log::Component
	Component for gRPC client logging. More...
class	ugrpc::client::SimpleClientComponent< Client >
	Template class for a simple gRPC client. More...
class	ugrpc::server::middlewares::baggage::Component
	Component for gRPC server baggage. More...
class	ugrpc::server::middlewares::congestion_control::Component
	Component for gRPC server logging. More...
class	ugrpc::server::middlewares::deadline_propagation::Component
	Component for gRPC server deadline propagation. More...
class	ugrpc::server::middlewares::log::Component
	Component for gRPC server logging. More...
class	ugrpc::server::ServerComponent
	Component that configures and manages the gRPC server. More...
class	ugrpc::server::ServiceComponentBase
	Base class for all the gRPC service components. More...
class	components::RabbitMQ
	RabbitMQ (AMQP 0.9.1) client component. More...
class	storages::mysql::Component
	MySQL/MariaDB client component. More...

Functions
ComponentList	components::CommonComponentList ()
	Returns the most common list of components with runtime config updates and HTTP client.
ComponentList	components::CommonServerComponentList ()
	Returns the most common list of components to start a fully functional server.
ComponentList	components::MinimalComponentList ()
	Returns a list of components to do basic logging, component initialization and configuration.
ComponentList	components::MinimalServerComponentList ()
	Returns a list of components to start a basic HTTP server.

Detailed Description

Components that could be used with utils::DaemonMain like functions; see Component system for an intro.

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Go backClientsUp nextSynchronization Primitives

Function Documentation

CommonComponentList()

ComponentList components::CommonComponentList

(

)

Returns the most common list of components with runtime config updates and HTTP client.

The list contains:

• os_signals::ProcessorComponent
• components::Logging
• components::Tracer
• components::ManagerControllerComponent
• components::StatisticsStorage
• components::DynamicConfig
• components::LoggingConfigurator
• components::DumpConfigurator
• components::TestsuiteSupport
• components::SystemStatisticsCollector
• components::HttpClient (default and "http-client-statistics")
• clients::dns::Component
• components::DynamicConfigClient
• components::DynamicConfigClientUpdater
• engine::TaskProcessorsLoadMonitor

Examples

samples/production_service/production_service.cpp.

CommonServerComponentList()

ComponentList components::CommonServerComponentList

(

)

Returns the most common list of components to start a fully functional server.

The list contains:

• components::Server
• server::handlers::DnsClientControl
• server::handlers::DynamicDebugLog
• server::handlers::ImplicitOptionsHttpHandler
• server::handlers::InspectRequests
• server::handlers::Jemalloc
• server::handlers::LogLevel
• server::handlers::OnLogRotate
• server::handlers::ServerMonitor
• server::handlers::TestsControl
• components::AuthCheckerSettings
• server::handlers::auth::DigestCheckerSettingsComponent
• server::handlers::auth::NonceCacheSettingsComponent
• congestion_control::Component
• components::HttpServerSettings
• tracing::DefaultTracingManagerLocator

Examples

samples/production_service/production_service.cpp.

MinimalComponentList()

ComponentList components::MinimalComponentList

(

)

Returns a list of components to do basic logging, component initialization and configuration.

The list contains:

• os_signals::ProcessorComponent
• components::Logging
• components::Tracer
• components::ManagerControllerComponent
• components::StatisticsStorage
• components::DynamicConfig
• components::DynamicConfigFallbacksComponent
• tracing::DefaultTracingManagerLocator

Examples

samples/tcp_service/tcp_service.cpp.

MinimalServerComponentList()

ComponentList components::MinimalServerComponentList

(

)

Returns a list of components to start a basic HTTP server.

The list contains:

• components::HttpServerSettings
• components::Server
• components::AuthCheckerSettings
• components::Logging
• components::Tracer
• components::ManagerControllerComponent
• components::StatisticsStorage
• components::DynamicConfig
• components::DynamicConfigFallbacksComponent

Examples

postgresql/functional_tests/basic_chaos/postgres_service.cpp, samples/config_service/config_service.cpp, samples/flatbuf_service/flatbuf_service.cpp, samples/grpc_service/grpc_service.cpp, samples/hello_service/hello_service.cpp, samples/http_caching/http_caching.cpp, samples/mongo_service/mongo_service.cpp, samples/postgres_auth/postgres_service.cpp, samples/postgres_service/postgres_service.cpp, samples/redis_service/redis_service.cpp, samples/tcp_full_duplex_service/tcp_full_duplex_service.cpp, and samples/websocket_service/websocket_service.cpp.