components::ClickHouse Class Reference

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

Detailed Description

ClickHouse client component.

Provides access to a ClickHouse cluster.

Static configuration example:

# yaml
        clickhouse-database:
            secdist_alias: clickhouse-database-alias
            initial_pool_size: 5
            max_pool_size: 10
            queue_timeout: 1s
            use_secure_connection: false
            compression: lz4

If the component is configured with an secdist_alias, it will lookup connection data in secdist.json via secdist_alias value, otherwise via components name.

Secdist format

A ClickHouse alias in secdist is described as a JSON object clickhouse_settings, containing descriptions of databases.

import json
 
import pytest
 
from testsuite.databases.clickhouse import discover
 
pytest_plugins = ['pytest_userver.plugins.clickhouse']
 
 
@pytest.fixture(scope='session')
def service_env(clickhouse_conn_info) -> dict:
    secdist_config = {
        'clickhouse_settings': {
            'clickhouse-database-alias': {
                'hosts': [clickhouse_conn_info.host],
                'port': clickhouse_conn_info.tcp_port,
                'password': '',
                'user': 'default',
                'dbname': 'clickhouse-database',
            },
        },
    }
 
    return {'SECDIST_CONFIG': json.dumps(secdist_config)}
 
 
@pytest.fixture(scope='session')
def clickhouse_local(service_source_dir):
    return discover.find_schemas(
        schema_dirs=[service_source_dir.joinpath('schemas', 'clickhouse')],
        dbprefix='',
    )

Static options:

Name	Description	Default value
secdist_alias	name of the key in secdist config	components name
initial_pool_size	number of connections created initially	5
max_pool_size	maximum number of created connections	10
queue_timeout	client waiting for a free connection time limit	1s
use_secure_connection	whether to use TLS for connections	true
compression	compression method to use (none / lz4)	none

Definition at line 57 of file component.hpp.

Inheritance diagram for components::ClickHouse:

Collaboration diagram for components::ClickHouse:

Public Member Functions
	ClickHouse (const ComponentConfig &, const ComponentContext &)
	Component constructor.
	~ClickHouse () override
	Component destructor.
std::shared_ptr< storages::clickhouse::Cluster >	GetCluster () const
	Cluster accessor.
Public Member Functions inherited from components::LoggableComponentBase
	LoggableComponentBase (const ComponentConfig &, const ComponentContext &)
	LoggableComponentBase (LoggableComponentBase &&)=delete
	LoggableComponentBase (const LoggableComponentBase &)=delete
	~LoggableComponentBase () override=default
ComponentHealth	GetComponentHealth () const override
void	OnLoadingCancelled () override
void	OnAllComponentsLoaded () override
void	OnAllComponentsAreStopping () override

Static Public Member Functions
static yaml_config::Schema	GetStaticConfigSchema ()
Static Public Member Functions inherited from components::LoggableComponentBase
static yaml_config::Schema	GetStaticConfigSchema ()

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

• userver/storages/clickhouse/component.hpp