Clickhouse

Description

Use Clickhouse-jdbc to correspond the data source according to the field name and write it into ClickHouse. The corresponding data table needs to be created in advance before use

tip

Engine Supported and plugin name

• Spark: Clickhouse
• Flink: Clickhouse

Options

name	type	required	default value
bulk_size	number	no	20000
clickhouse.*	string	no
database	string	yes	-
fields	array	no	-
host	string	yes	-
password	string	no	-
retry	number	no	1
retry_codes	array	no	[ ]
table	string	yes	-
username	string	no	-
split_mode	boolean	no	false
sharding_key	string	no	-
common-options	string	no	-

bulk_size [number]

The number of rows written through Clickhouse-jdbc each time, the default is 20000 .

database [string]

database name

fields [array]

The data field that needs to be output to ClickHouse , if not configured, it will be automatically adapted according to the data schema .

host [string]

ClickHouse cluster address, the format is host:port , allowing multiple hosts to be specified. Such as "host1:8123,host2:8123" .

password [string]

ClickHouse user password . This field is only required when the permission is enabled in ClickHouse .

retry [number]

The number of retries, the default is 1

retry_codes [array]

When an exception occurs, the ClickHouse exception error code of the operation will be retried. For a detailed list of error codes, please refer to ClickHouseErrorCode

If multiple retries fail, this batch of data will be discarded, use with caution! !

table [string]

table name

username [string]

ClickHouse user username, this field is only required when permission is enabled in ClickHouse

clickhouse [string]

In addition to the above mandatory parameters that must be specified by clickhouse-jdbc , users can also specify multiple optional parameters, which cover all the parameters provided by clickhouse-jdbc .

The way to specify the parameter is to add the prefix clickhouse. to the original parameter name. For example, the way to specify socket_timeout is: clickhouse.socket_timeout = 50000 . If these non-essential parameters are not specified, they will use the default values given by clickhouse-jdbc.

split_mode [boolean]

This mode only support clickhouse table which engine is 'Distributed'.And internal_replication option should be true. They will split distributed table data in seatunnel and perform write directly on each shard. The shard weight define is clickhouse will be counted.

sharding_key [string]

When use split_mode, which node to send data to is a problem, the default is random selection, but the 'sharding_key' parameter can be used to specify the field for the sharding algorithm. This option only worked when 'split_mode' is true.

common options [string]

Sink plugin common parameters, please refer to common options for details

ClickHouse type comparison table

ClickHouse field type	Convert plugin conversion goal type	SQL conversion expression	Description
Date	string	string()	yyyy-MM-dd Format string
DateTime	string	string()	yyyy-MM-dd HH:mm:ss Format string
String	string	string()
Int8	integer	int()
Uint8	integer	int()
Int16	integer	int()
Uint16	integer	int()
Int32	integer	int()
Uint32	long	bigint()
Int64	long	bigint()
Uint64	long	bigint()
Float32	float	float()
Float64	double	double()
Decimal(P, S)	-	CAST(source AS DECIMAL(P, S))	Decimal32(S), Decimal64(S), Decimal128(S) Can be used
Array(T)	-	-
Nullable(T)	Depends on T	Depends on T
LowCardinality(T)	Depends on T	Depends on T

Examples

clickhouse {
    host = "localhost:8123"
    clickhouse.socket_timeout = 50000
    database = "nginx"
    table = "access_msg"
    fields = ["date", "datetime", "hostname", "http_code", "data_size", "ua", "request_time"]
    username = "username"
    password = "password"
    bulk_size = 20000
}

ClickHouse {
    host = "localhost:8123"
    database = "nginx"
    table = "access_msg"
    fields = ["date", "datetime", "hostname", "http_code", "data_size", "ua", "request_time"]
    username = "username"
    password = "password"
    bulk_size = 20000
    retry_codes = [209, 210]
    retry = 3
}

In case of network timeout or network abnormality, retry writing 3 times