Clickhouse Sink

The Vector clickhouse sink batches log events to Clickhouse via the HTTP Interface.

Configuration

• Common
• Advanced

vector.toml

[sinks.my_sink_id]
  # REQUIRED - General
  type = "clickhouse" # example, must be: "clickhouse"
  inputs = ["my-source-id"] # example
  host = "http://localhost:8123" # example
  table = "mytable" # example
  
  # OPTIONAL - General
  database = "mydatabase" # example, no default
  
  # OPTIONAL - Basic auth
  [sinks.my_sink_id.basic_auth]
    password = "${PASSWORD_ENV_VAR}" # example
    user = "${USERNAME_ENV_VAR}" # example

Options

16 items

common onlyrequired only

commontableoptional

basic_auth

Options for basic authentication.

commonstringrequired

password

The basic authentication password.

No default

View examples

commonstringrequired

user

The basic authentication user name.

No default

View examples

intbytesoptional

batch_size

The maximum size of a batch before it is flushed. See Buffers & Batches for more info.

Default: 1049000

View examples

intsecondsoptional

batch_timeout

The maximum age of a batch before it is flushed. See Buffers & Batches for more info.

Default: 1

View examples

tableoptional

buffer

Configures the sink specific buffer.

intbytesoptional

max_size

The maximum size of the buffer on the disk.

No default

Only relevant when: type = "disk"

View examples

inteventsoptional

num_items

The maximum number of events allowed in the buffer.

Default: 500

Only relevant when: type = "memory"

View examples

stringenumoptional

type

The buffer's type / location. disk buffers are persistent and will be retained between restarts.

Default: "memory"

Enum, must be one of: "memory" "disk"

View examples

stringenumoptional

when_full

The behavior when the buffer becomes full.

Default: "block"

Enum, must be one of: "block" "drop_newest"

View examples

stringenumoptional

compression

The compression strategy used to compress the encoded event data before outputting.

Default: "gzip"

Enum, must be one of: "gzip"

View examples

commonstringoptional

database

The database that contains the stable that data will be inserted into.

No default

View examples

booloptional

healthcheck

Enables/disables the sink healthcheck upon start. See Health Checks for more info.

Default: true

View examples

commonstringrequired

host

The host url of the Clickhouse server.

No default

View examples

intoptional

request_in_flight_limit

The maximum number of in-flight requests allowed at any given time. See Rate Limits for more info.

Default: 5

View examples

intsecondsoptional

request_rate_limit_duration_secs

The window used for the request_rate_limit_num option See Rate Limits for more info.

Default: 1

View examples

intoptional

request_rate_limit_num

The maximum number of requests allowed within the request_rate_limit_duration_secs window. See Rate Limits for more info.

Default: 5

View examples

intoptional

request_retry_attempts

The maximum number of retries to make for failed requests. See Retry Policy for more info.

Default: 9223372036854776000

View examples

intsecondsoptional

request_retry_backoff_secs

The amount of time to wait before attempting a failed request again. See Retry Policy for more info.

Default: 1

View examples

intsecondsoptional

request_timeout_secs

The maximum time a request can take before being aborted. It is highly recommended that you do not lower value below the service's internal timeout, as this could create orphaned requests, pile on retries, and result in deuplicate data downstream.

Default: 30

View examples

commonstringrequired

table

The table that data will be inserted into.

No default

View examples

tableoptional

tls

Configures the TLS options for connections from this sink.

stringoptional

ca_path

Absolute path to an additional CA certificate file, in DER or PEM format (X.509).

No default

View examples

stringoptional

crt_path

Absolute path to a certificate file used to identify this connection, in DER or PEM format (X.509) or PKCS#12. If this is set and is not a PKCS#12 archive, key_path must also be set.

No default

View examples

stringoptional

key_pass

Pass phrase used to unlock the encrypted key file. This has no effect unless key_pass above is set.

No default

View examples

stringoptional

key_path

Absolute path to a certificate key file used to identify this connection, in DER or PEM format (PKCS#8). If this is set, crt_path must also be set.

No default

View examples

booloptional

verify_certificate

If true (the default), Vector will validate the TLS certificate of the remote host. Do NOT set this to false unless you understand the risks of not verifying the remote certificate.

Default: true

View examples

booloptional

verify_hostname

If true (the default), Vector will validate the configured remote host name against the remote host's TLS certificate. Do NOT set this to false unless you understand the risks of not verifying the remote hostname.

Default: true

View examples

How It Works

Buffers & Batches

The clickhouse sink buffers & batches data as shown in the diagram above. You'll notice that Vector treats these concepts differently, instead of treating them as global concepts, Vector treats them as sink specific concepts. This isolates sinks, ensuring services disruptions are contained and delivery guarantees are honored.

Batches are flushed when 1 of 2 conditions are met:

1. The batch age meets or exceeds the configured batch_timeout (default: 1 seconds).
2. The batch size meets or exceeds the configured batch_size (default: 1049000 bytes).

Buffers are controlled via the buffer.* options.

Environment Variables

Environment variables are supported through all of Vector's configuration. Simply add ${MY_ENV_VAR} in your Vector configuration file and the variable will be replaced before being evaluated.

You can learn more in the Environment Variables section.

Health Checks

Health checks ensure that the downstream service is accessible and ready to accept data. This check is performed upon sink initialization. If the health check fails an error will be logged and Vector will proceed to start.

Require Health Checks

If you'd like to exit immediately upon a health check failure, you can pass the --require-healthy flag:

vector --config /etc/vector/vector.toml --require-healthy

Disable Health Checks

If you'd like to disable health checks for this sink you can set the healthcheck option to false.

Rate Limits

Vector offers a few levers to control the rate and volume of requests to the downstream service. Start with the request_rate_limit_duration_secs and request_rate_limit_num options to ensure Vector does not exceed the specified number of requests in the specified window. You can further control the pace at which this window is saturated with the request_in_flight_limit option, which will guarantee no more than the specified number of requests are in-flight at any given time.

Please note, Vector's defaults are carefully chosen and it should be rare that you need to adjust these. If you found a good reason to do so please share it with the Vector team by opening an issie.

Retry Policy

Vector will retry failed requests (status == 429, >= 500, and != 501). Other responses will not be retried. You can control the number of retry attempts and backoff rate with the request_retry_attempts and request_retry_backoff_secs options.