components::Mongo Class Reference

#include <userver/storages/mongo/component.hpp>

Detailed Description

MongoDB client component.

Provides access to a MongoDB database.

Dynamic options:

• MONGO_CONGESTION_CONTROL_DATABASES_SETTINGS
• MONGO_CONGESTION_CONTROL_ENABLED
• MONGO_CONGESTION_CONTROL_SETTINGS
• MONGO_CONNECTION_POOL_SETTINGS
• MONGO_DEFAULT_MAX_TIME_MS

Static configuration example:

mongo-taxi:
  dbalias: taxi
  appname: userver-sample
  conn_timeout: 2s
  so_timeout: 10s
  queue_timeout: 1s
  initial_size: 16
  max_size: 128
  idle_limit: 64
  connecting_limit: 8
  local_threshold: 15ms
  maintenance_period: 15s
  stats_verbosity: terse

You must specify one of dbalias or dbconnection.

Static options:

Name	Description	Default value
dbalias	name of the database in secdist config (if available)	–
dbconnection	connection string (used if no dbalias specified)	–
appname	application name for the DB server	userver
conn_timeout	connection timeout	2s
so_timeout	socket timeout	10s
queue_timeout	max connection queue wait time	1s
initial_size	number of connections created initially	16
max_size	limit for total connections number	128
idle_limit	limit for idle connections number	64
connecting_limit	limit for establishing connections number	8
local_threshold	latency window for instance selection	mongodb default
max_replication_lag	replication lag limit for usable secondaries, min. 90s	-
maintenance_period	pool maintenance period (idle connections pruning etc.)	15s
stats_verbosity	changes the granularity of reported metrics	'terse'
dns_resolver	server hostname resolver type (getaddrinfo or async)	'async'

stats_verbosity accepts one of the following values:

Value	Description
terse	Default value, report only cumulative stats and read/write totals
full	Separate metrics for each operation, divided by read preference or write concern

It is a common practice to provide a database connection string via environment variables. To retrieve a value from the environment use dbconnection#env: THE_ENV_VARIABLE_WITH_CONNECTION_STRING as described in yaml_config::YamlConfig.

Secdist format

If a dbalias option is provided, for example dbalias: some_name_of_your_database, then the Secdist entry for that alias should look like following:

{
  "mongo_settings": {
    "some_name_of_your_database": {
      "dbsettings": {
        "uri": "mongodb://user:password@host:port/database_name"
      }
    }
  }
}

Examples

samples/mongo_service/mongo_service.cpp.

Definition at line 99 of file component.hpp.

Inheritance diagram for components::Mongo:

Public Member Functions
	Mongo (const ComponentConfig &, const ComponentContext &)
	Component constructor.
	~Mongo () override
	Component destructor.
storages::mongo::PoolPtr	GetPool () const
	Client pool accessor.
ComponentHealth	GetComponentHealth () const override
void	OnLoadingCancelled () override
void	OnAllComponentsLoaded () override
void	OnAllComponentsAreStopping () override

Static Public Member Functions
static yaml_config::Schema	GetStaticConfigSchema ()

Protected Types
using	LoggableComponentBase = ComponentBase
	Legacy alias, use ComponentBase instead.

Member Typedef Documentation

LoggableComponentBase

using components::ComponentBase::LoggableComponentBase = ComponentBase

protectedinherited

Legacy alias, use ComponentBase instead.

Definition at line 69 of file component_base.hpp.

Member Function Documentation

GetComponentHealth()

ComponentHealth components::ComponentBase::GetComponentHealth ( ) const

inlineoverridevirtualinherited

Override this function to inform the world of the state of your component.

Warning

The function is called concurrently from multiple threads.

Reimplemented from components::RawComponentBase.

Definition at line 35 of file component_base.hpp.

OnAllComponentsAreStopping()

void components::ComponentBase::OnAllComponentsAreStopping ( )

inlineoverridevirtualinherited

Component may use this function to stop doing work before the stop of the components that depend on it.

Base components may override it and make final to do some work before the derived object constructor is called. Don't use it otherwise.

Reimplemented from components::RawComponentBase.

Reimplemented in urabbitmq::ConsumerComponentBase, and components::Server.

Definition at line 60 of file component_base.hpp.

OnAllComponentsLoaded()

void components::ComponentBase::OnAllComponentsLoaded ( )

inlineoverridevirtualinherited

Component may use this function to finalize registration of other components that depend on it (for example, handler components register in server component, and the latter uses OnAllComponentsLoaded() to start processing requests).

Base components may override it and make final to do some work after the derived object constructor is called. Don't use it otherwise.

Reimplemented from components::RawComponentBase.

Reimplemented in urabbitmq::ConsumerComponentBase, components::Server, and server::handlers::Ping.

Definition at line 53 of file component_base.hpp.

OnLoadingCancelled()

void components::ComponentBase::OnLoadingCancelled ( )

inlineoverridevirtualinherited

Called once if the creation of any other component failed. If the current component expects some other component to take any action with the current component, this call is a signal that such action may never happen due to components loading was cancelled. Application components might not want to override it.

Reimplemented from components::RawComponentBase.

Definition at line 44 of file component_base.hpp.

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The documentation for this class was generated from the following file:

• userver/storages/mongo/component.hpp