ClickHouse

ClickHouse (clickhouse)

Write events to a ClickHouse table using the HTTP interface or native endpoint.

Database json

Minimal example

output:
  clickhouse:
    endpoint: ~
    table: ~

JSON

{
  "output": {
    "clickhouse": {
      "endpoint": null,
      "table": null
    }
  }
}

Contents

• Minimal example

• Fields

• Connection

• Payload

• Schema

• Authentication

• Schema

Fields

Field	Type	Required	Description
endpoint Connection	string	✅	Base endpoint (example: https://localhost:8443 or http://cluster-router:8123).
table Connection	string	✅	Target table for writes.
retry	Retry		How to retry failed inserts.
batch	Batch		Batch events before inserting.
database Connection	string		Optional database override; defaults to server-side default database.
input-field Payload	field (string)		Optional event field to treat as the raw payload. When omitted the entire event is used. Examples: data_field
columns Schema	Columns[]		Declarative column mapping; leave empty to stream JSONEachRow documents.
format Payload	Format		Insert format to use when sending data to ClickHouse. Allowed values: json-each-row, json-compact-each-row, csv, values
auth Authentication	Auth		Optional authentication settings (basic auth, token, or TLS material).
compression Connection	Compression		Optional compression codec negotiated with the server. Allowed values: none, lz4
settings Connection	map (string)		Additional ClickHouse setting key/value pairs (forwarded as query params).
insecure-skip-verify Connection	boolean (bool)		Skip TLS certificate verification (development only).
timezone Connection	string		Optional timezone override used when formatting temporal data.

Connection

Show fields

Field	Type	Required	Description
endpoint	string	✅	Base endpoint (example: https://localhost:8443 or http://cluster-router:8123).
table	string	✅	Target table for writes.
database	string		Optional database override; defaults to server-side default database.
compression	Compression		Optional compression codec negotiated with the server. Allowed values: none, lz4
settings	map (string)		Additional ClickHouse setting key/value pairs (forwarded as query params).
insecure-skip-verify	boolean (bool)		Skip TLS certificate verification (development only).
timezone	string		Optional timezone override used when formatting temporal data.

Payload

Show fields

Field	Type	Required	Description
input-field	field (string)		Optional event field to treat as the raw payload. When omitted the entire event is used. Examples: data_field
format	Format		Insert format to use when sending data to ClickHouse. Allowed values: json-each-row, json-compact-each-row, csv, values

Schema

Show fields

Field	Type	Required	Description
columns	Columns[]		Declarative column mapping; leave empty to stream JSONEachRow documents.

Authentication

Show fields

Field	Type	Required	Description
auth	Auth		Optional authentication settings (basic auth, token, or TLS material).

Schema

• Retry Fields
• Batch Fields
• Columns Fields
• Auth Fields
• Settings Table
• Batch - Mode Options
• Format Options
• Compression Options

Retry Fields

Field	Type	Required	Description
timeout	time-interval (string)	✅	timeout (e.g. 500ms, 2s etc. - default is 30). Examples: 500ms, 2h
retries	number (integer)		number of retries. Examples: 42, 1.2e-10

Batch Fields

Field	Type	Required	Description
fixed-size	number (integer)		maximum number of events in an output batch. Examples: 42, 1.2e-10
mode	Mode	✅	If ‘document’ send on end of document generated by input. If ‘fixed’, use fixed_size. Allowed values: fixed, document
timeout	time-interval (string)	✅	interval after which the batch is sent, to keep throughput going (default 100ms). Examples: 500ms, 2h
header	multiline-text (string)		put a header line before the batch.
footer	multiline-text (string)		put a header line after the last line of the batch.
use-document-marker	boolean (bool)		Enrich the job metadata with a document marker (for document handling in batch mode).
wrap-as-json	boolean (bool)		Format the output batch as a JSON array.

Columns Fields

Field	Type	Required	Description
name	string	✅
field	string		Event field name (dot-notation) to pull data from.
pointer	json-pointer (string)		JSON Pointer to extract from the event (used when field is insufficient).
expression	string		Optional ClickHouse expression to compute the column.
r-type	string		Explicit ClickHouse type (e.g. DateTime64(3), Nullable(String)).
default	string		Default value used when the source field/pointer resolves to null.
codec	string		Optional codec hint (e.g. LZ4, ZSTD).

Auth Fields

Field	Type	Required	Description
username	string
password	string
access-token	string
tls-certificate	string
tls-key	string

Settings Table

Setting	Value
setting.name	value

Value format: templated-text.

Batch - Mode Options

Value	Description
fixed	Fixed
document	Document

Format Options

Value	Description
json-each-row	Json Each Row
json-compact-each-row	Json Compact Each Row
csv	Csv
values	Values

Compression Options

Value	Description
none	None
lz4	Lz4