ClickHouse

Overview

The ClickHouse Load Node supports to write data into ClickHouse database. This document describes how to set up the ClickHouse Load Node to run SQL queries against ClickHouse database.

Supported Version

Load Node	Driver	Group Id	Artifact Id	JAR
ClickHouse	ClickHouse	ru.yandex.clickhouse	clickhouse-jdbc	Download

Dependencies

In order to set up the ClickHouse Load Node, the following provides dependency information for both projects using a build automation tool (such as Maven or SBT) and SQL Client with Sort Connectors JAR bundles.

Maven dependency

<dependency>
    <groupId>org.apache.inlong</groupId>
    <artifactId>sort-connector-jdbc</artifactId>
    <version>1.13.0-SNAPSHOT</version>
</dependency>

How to create a ClickHouse Load Node

Usage for SQL API

-- MySQL extract node
CREATE TABLE `mysql_extract_table`(
  PRIMARY KEY (`id`) NOT ENFORCED,
  `id` BIGINT,
  `name` STRING,
  `age` INT
) WITH (
  'connector' = 'mysql-cdc-inlong',
  'url' = 'jdbc:mysql://localhost:3306/read',
  'username' = 'inlong',
  'password' = 'inlong',
  'table-name' = 'user'
)

-- ClickHouse load node
CREATE TABLE `clickhouse_load_table`(
  PRIMARY KEY (`id`) NOT ENFORCED,
  `id` BIGINT,
  `name` STRING,
  `age` INT
) WITH (
  'connector' = 'jdbc-inlong',
  'dialect-impl' = 'org.apache.inlong.sort.jdbc.dialect.ClickHouseDialect',
  'url' = 'jdbc:clickhouse://localhost:8123/demo',
  'username' = 'inlong',
  'password' = 'inlong',
  'table-name' = 'demo.user'
)

-- write data into ClickHouse
INSERT INTO clickhouse_load_table 
SELECT id, name , age FROM mysql_extract_table;  

Usage for InLong Dashboard

When creating a data flow, select ClickHouse for the data stream direction, and click "Add" to configure it.

Usage for InLong Manager Client

TODO: It will be supported in the future.

ClickHouse Load Node Options

Option	Required	Default	Type	Description
connector	required	(none)	String	Specify what connector to use, here should be 'jdbc-inlong'.
url	required	(none)	String	The JDBC database url.
dialect-impl	required	(none)	String	org.apache.inlong.sort.jdbc.dialect.ClickHouseDialect
table-name	required	(none)	String	The name of JDBC table to connect, for example database.tableName
driver	optional	(none)	String	The class name of the JDBC driver to use to connect to this URL, if not set, it will automatically be derived from the URL.
username	optional	(none)	String	The JDBC user name. 'username' and 'password' must both be specified if any of them is specified.
password	optional	(none)	String	The JDBC password.
connection.max-retry-timeout	optional	60s	Duration	Maximum timeout between retries. The timeout should be in second granularity and shouldn't be smaller than 1 second.
sink.buffer-flush.max-rows	optional	100	Integer	The max size of buffered records before flush. Can be set to zero to disable it.
sink.buffer-flush.interval	optional	1s	Duration	The flush interval mills, over this time, asynchronous threads will flush data. Can be set to '0' to disable it. Note, 'sink.buffer-flush.max-rows' can be set to '0' with the flush interval set allowing for complete async processing of buffered actions.
sink.max-retries	optional	3	Integer	The max retry times if writing records to database failed.
sink.parallelism	optional	(none)	Integer	Defines the parallelism of the JDBC sink operator. By default, the parallelism is determined by the framework using the same parallelism of the upstream chained operator.
sink.ignore.changelog	optional	false	Boolean	Ignore all RowKind, ingest them as INSERT.
inlong.metric.labels	optional	(none)	String	Inlong metric label, format of value is groupId={groupId}&streamId={streamId}&nodeId={nodeId}.

Data Type Mapping

ClickHouse type	Flink SQL type
String	CHAR
String IP UUID	VARCHAR
String EnumL	STRING
UInt8	BOOLEAN
FixedString	BYTES
Decimal Int128 Int256 UInt64 UInt128 UInt256	DECIMAL
Int8	TINYINT
Int16 UInt8	SMALLINT
Int32 UInt16 Interval	INTEGER
Int64 UInt32	BIGINT
Float32	FLOAT
Date	DATE
DateTime	TIME
DateTime	TIMESTAMP
DateTime	TIMESTAMP_LTZ
Int32	INTERVAL_YEAR_MONTH
Int64	INTERVAL_DAY_TIME
Array	ARRAY
Map	MAP
Not supported	ROW
Not supported	MULTISET
Not supported	RAW