Cloud

arc

Available in: Cloud, Self-Managed

Writes data to an Arc database via the msgpack ingestion endpoint.

This output sends data to an Arc columnar analytical database using its high-performance MessagePack ingestion endpoint.

Arc supports two payload formats:

  • columnar (default): Transposes batched messages into column arrays. This is the recommended format, offering significantly faster ingestion.

  • row: Sends each message as an individual row record with fields and optional tags.

Data is encoded as MessagePack and optionally compressed with zstd (recommended) or gzip before being sent to the Arc endpoint.

In columnar mode, all messages within a single batch must have the same set of fields. Arc validates that all column arrays have equal length and rejects batches with mismatched columns. Schema evolution across separate batches is fully supported. Use row format if messages within a batch have varying schemas.

  • Common

  • Advanced

outputs:
  label: ""
  arc:
    base_url: "" # No default (required)
    timeout: 5s
    token: "" # No default (optional)
    database: default
    measurement: "" # No default (required)
    format: columnar
    tags_mapping: "" # No default (optional)
    compression: zstd
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: [] # No default (optional)
outputs:
  label: ""
  arc:
    base_url: "" # No default (required)
    timeout: 5s
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    proxy_url: ""
    disable_http2: false
    tps_limit: 0
    tps_burst: 1
    backoff:
      initial_interval: 1s
      max_interval: 30s
      max_retries: 3
    tcp:
      connect_timeout: 0s
      keep_alive:
        idle: 15s
        interval: 15s
        count: 9
      tcp_user_timeout: 0s
    http:
      max_idle_conns: 100
      max_idle_conns_per_host: 0
      max_conns_per_host: 64
      idle_conn_timeout: 1m30s
      tls_handshake_timeout: 10s
      expect_continue_timeout: 1s
      response_header_timeout: 0s
      disable_keep_alives: false
      disable_compression: false
      max_response_header_bytes: 1048576
      max_response_body_bytes: 10485760
      write_buffer_size: 4096
      read_buffer_size: 4096
      h2:
        strict_max_concurrent_requests: false
        max_decoder_header_table_size: 4096
        max_encoder_header_table_size: 4096
        max_read_frame_size: 16384
        max_receive_buffer_per_connection: 1048576
        max_receive_buffer_per_stream: 1048576
        send_ping_timeout: 0s
        ping_timeout: 15s
        write_byte_timeout: 0s
    access_log_level: ""
    access_log_body_limit: 0
    token: "" # No default (optional)
    database: default
    measurement: "" # No default (required)
    format: columnar
    timestamp_field: ""
    timestamp_unit: auto
    tags_mapping: "" # No default (optional)
    compression: zstd
    max_in_flight: 64
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: [] # No default (optional)

Fields

access_log_body_limit

Maximum bytes of request/response body to include in logs. 0 to skip body logging.

Type: int

Default: 0

access_log_level

Log level for HTTP request/response logging. Empty disables logging.

Type: string

Default: ""

Options: `, `TRACE, DEBUG, INFO, WARN, ERROR

backoff

Adaptive backoff configuration for 429 (Too Many Requests) responses. Always active.

Type: object

backoff.initial_interval

Initial interval between retries on 429 responses.

Type: string

Default: 1s

backoff.max_interval

Maximum interval between retries on 429 responses.

Type: string

Default: 30s

backoff.max_retries

Maximum number of retries on 429 responses.

Type: int

Default: 3

base_url

Base URL of the target service (e.g., https://api.example.com). TLS is enabled automatically for https URLs.

Type: string

batching

Allows you to configure a batching policy.

Type: object

# Examples:
batching:
  byte_size: 5000
  count: 0
  period: 1s

# ---

batching:
  count: 10
  period: 1s

# ---

batching:
  check: this.contains("END BATCH")
  count: 0
  period: 1m

batching.byte_size

An amount of bytes at which the batch should be flushed. If 0 disables size based batching.

Type: int

Default: 0

batching.check

A Bloblang query that should return a boolean value indicating whether a message should end a batch.

Type: string

Default: ""

# Examples:
check: this.type == "end_of_transaction"

batching.count

A number of messages at which the batch should be flushed. If 0 disables count based batching.

Type: int

Default: 0

batching.period

A period in which an incomplete batch should be flushed regardless of its size.

Type: string

Default: ""

# Examples:
period: 1s

# ---

period: 1m

# ---

period: 500ms

batching.processors[]

A list of processors to apply to a batch as it is flushed. This allows you to aggregate and archive the batch however you see fit. Please note that all resulting messages are flushed as a single batch, therefore splitting the batch into smaller batches using these processors is a no-op.

Type: processor

# Examples:
processors:
  - archive:
      format: concatenate


# ---

processors:
  - archive:
      format: lines


# ---

processors:
  - archive:
      format: json_array

compression

Compression algorithm for the request body. zstd is recommended for best decompression performance in Arc.

Type: string

Default: zstd

Options: zstd, gzip, none

database

The target database name.

Type: string

Default: default

disable_http2

Disable HTTP/2 and force HTTP/1.1.

Type: bool

Default: false

format

The payload format. columnar transposes batch messages into column arrays for best performance. row sends each message as an individual record.

Type: string

Default: columnar

Options: columnar, row

http

HTTP transport settings controlling connection pooling, timeouts, and HTTP/2.

Type: object

http.disable_compression

Disable automatic decompression of gzip responses.

Type: bool

Default: false

http.disable_keep_alives

Disable HTTP keep-alive connections; each request uses a new connection.

Type: bool

Default: false

http.expect_continue_timeout

Maximum time to wait for a server’s 100-continue response before sending the body. 0 means the body is sent immediately.

Type: string

Default: 1s

http.h2

HTTP/2-specific transport settings. Only applied when HTTP/2 is enabled.

Type: object

http.h2.max_decoder_header_table_size

Upper limit in bytes for the HPACK header table used to decode headers from the peer. Must be less than 4 MiB.

Type: int

Default: 4096

http.h2.max_encoder_header_table_size

Upper limit in bytes for the HPACK header table used to encode headers sent to the peer. Must be less than 4 MiB.

Type: int

Default: 4096

http.h2.max_read_frame_size

Largest HTTP/2 frame this endpoint will read. Valid range: 16 KiB to 16 MiB.

Type: int

Default: 16384

http.h2.max_receive_buffer_per_connection

Maximum flow-control window size in bytes for data received on a connection. Must be at least 64 KiB and less than 4 MiB.

Type: int

Default: 1048576

http.h2.max_receive_buffer_per_stream

Maximum flow-control window size in bytes for data received on a single stream. Must be less than 4 MiB.

Type: int

Default: 1048576

http.h2.ping_timeout

Timeout waiting for a PING response before closing the connection.

Type: string

Default: 15s

http.h2.send_ping_timeout

Idle timeout after which a PING frame is sent to verify connection health. 0 disables health checks.

Type: string

Default: 0s

http.h2.strict_max_concurrent_requests

When true, new requests block when a connection’s concurrency limit is reached instead of opening a new connection.

Type: bool

Default: false

http.h2.write_byte_timeout

Timeout for writing data to a connection. The timer resets whenever bytes are written. 0 disables the timeout.

Type: string

Default: 0s

http.idle_conn_timeout

How long an idle connection remains in the pool before being closed. 0 disables the timeout.

Type: string

Default: 1m30s

http.max_conns_per_host

Maximum total connections (active + idle) per host. 0 means unlimited.

Type: int

Default: 64

http.max_idle_conns

Maximum total number of idle (keep-alive) connections across all hosts. 0 means unlimited.

Type: int

Default: 100

http.max_idle_conns_per_host

Maximum idle connections to keep per host. 0 (the default) uses GOMAXPROCS+1.

Type: int

Default: 0

http.max_response_body_bytes

Maximum bytes of response body the client will read. The response body is wrapped with a limit reader; reads beyond this cap return EOF. 0 disables the limit.

Type: int

Default: 10485760

http.max_response_header_bytes

Maximum bytes of response headers to allow.

Type: int

Default: 1048576

http.read_buffer_size

Size in bytes of the per-connection read buffer.

Type: int

Default: 4096

http.response_header_timeout

Maximum time to wait for response headers after writing the full request. 0 disables the timeout.

Type: string

Default: 0s

http.tls_handshake_timeout

Maximum time to wait for a TLS handshake to complete. 0 disables the timeout.

Type: string

Default: 10s

http.write_buffer_size

Size in bytes of the per-connection write buffer.

Type: int

Default: 4096

max_in_flight

The maximum number of messages to have in flight at a given time. Increase this to improve throughput.

Type: int

Default: 64

measurement

The measurement (table) name. Supports interpolation functions.

Type: string

# Examples:
measurement: cpu_metrics

# ---

measurement: ${!metadata("measurement")}

# ---

measurement: ${!json("type")}

proxy_url

HTTP proxy URL. Empty string disables proxying.

Type: string

Default: ""

tags_mapping

An optional Bloblang mapping to extract tags from each message. Only used in row format. The result must be a map[string]string.

Type: string

# Examples:
tags_mapping: root = {"host": this.hostname, "region": this.region}

tcp

TCP socket configuration.

Type: object

tcp.connect_timeout

Maximum amount of time a dial will wait for a connect to complete. Zero disables.

Type: string

Default: 0s

tcp.keep_alive

TCP keep-alive probe configuration.

Type: object

tcp.keep_alive.count

Maximum unanswered keep-alive probes before dropping the connection. Zero defaults to 9.

Type: int

Default: 9

tcp.keep_alive.idle

Duration the connection must be idle before sending the first keep-alive probe. Zero defaults to 15s. Negative values disable keep-alive probes.

Type: string

Default: 15s

tcp.keep_alive.interval

Duration between keep-alive probes. Zero defaults to 15s.

Type: string

Default: 15s

tcp.tcp_user_timeout

Maximum time to wait for acknowledgment of transmitted data before killing the connection. Linux-only (kernel 2.6.37+), ignored on other platforms. When enabled, keep_alive.idle must be greater than this value per RFC 5482. Zero disables.

Type: string

Default: 0s

timeout

HTTP request timeout.

Type: string

Default: 5s

timestamp_field

The field name within each message containing the timestamp. If empty, the current time is used. Supports Unix timestamps and RFC3339 strings.

Type: string

Default: ""

timestamp_unit

The unit of a numeric timestamp field. auto detects the unit based on magnitude. Ignored when timestamp_field is empty.

Type: string

Default: auto

Options: us, ms, s, ns, auto

tls

Custom TLS settings can be used to override system defaults.

Type: object

tls.client_certs[]

A list of client certificates to use. For each certificate either the fields cert and key, or cert_file and key_file should be specified, but not both.

Type: object

Default: []

# Examples:
client_certs:
  - cert: foo
    key: bar


# ---

client_certs:
  - cert_file: ./example.pem
    key_file: ./example.key

tls.client_certs[].cert

A plain text certificate to use.

Type: string

Default: ""

tls.client_certs[].cert_file

The path of a certificate to use.

Type: string

Default: ""

tls.client_certs[].key

A plain text certificate key to use.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Manage Secrets before adding it to your configuration.

Type: string

Default: ""

tls.client_certs[].key_file

The path of a certificate key to use.

Type: string

Default: ""

tls.client_certs[].password

A plain text password for when the private key is password encrypted in PKCS#1 or PKCS#8 format. The obsolete pbeWithMD5AndDES-CBC algorithm is not supported for the PKCS#8 format.

Because the obsolete pbeWithMD5AndDES-CBC algorithm does not authenticate the ciphertext, it is vulnerable to padding oracle attacks that can let an attacker recover the plaintext.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Manage Secrets before adding it to your configuration.

Type: string

Default: ""

# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}

tls.enable_renegotiation

Whether to allow the remote server to repeatedly request renegotiation. Enable this option if you’re seeing the error message local error: tls: no renegotiation.

Type: bool

Default: false

tls.enabled

Whether custom TLS settings are enabled.

Type: bool

Default: false

tls.root_cas

An optional root certificate authority to use. This is a string, representing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Manage Secrets before adding it to your configuration.

Type: string

Default: ""

# Examples:
root_cas: |-
  -----BEGIN CERTIFICATE-----
  ...
  -----END CERTIFICATE-----

tls.root_cas_file

An optional path of a root certificate authority file to use. This is a file, often with a .pem extension, containing a certificate chain from the parent trusted root certificate, to possible intermediate signing certificates, to the host certificate.

Type: string

Default: ""

# Examples:
root_cas_file: ./root_cas.pem

tls.skip_cert_verify

Whether to skip server side certificate verification.

Type: bool

Default: false

token

Bearer token for authentication.

This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Manage Secrets before adding it to your configuration.

Type: string

tps_burst

Maximum burst size for rate limiting.

Type: int

Default: 1

tps_limit

Rate limit in requests per second. 0 disables rate limiting.

Type: float

Default: 0

Performance

This output benefits from sending multiple messages in flight in parallel for improved performance. You can tune the max number of in flight messages (or message batches) with the field max_in_flight.

This output benefits from sending messages as a batch for improved performance. Batches can be formed at both the input and output level. You can find out more in this doc.