# arc

> For the complete documentation index, see [llms.txt](https://docs.redpanda.com/llms.txt). Component-specific: [cloud-data-platform-full.txt](https://docs.redpanda.com/cloud-data-platform-full.txt)

---
title: arc
latest-operator-version: v26.1.4
latest-console-tag: v3.7.3
latest-connect-version: 4.93.0
latest-redpanda-tag: v26.1.9
docname: connect/components/outputs/arc
page-component-name: cloud-data-platform
page-version: master
page-component-version: master
page-component-title: Cloud
page-relative-src-path: connect/components/outputs/arc.adoc
page-edit-url: https://github.com/redpanda-data/cloud-docs/edit/main/modules/develop/pages/connect/components/outputs/arc.adoc
description: Writes data to an Arc database via the msgpack ingestion endpoint.
page-git-created-date: "2026-04-20"
page-git-modified-date: "2026-05-26"
---

<!-- Source: https://docs.redpanda.com/cloud-data-platform/develop/connect/components/outputs/arc.md -->

**Available in:** Cloud, [Self-Managed](https://docs.redpanda.com/connect/components/outputs/arc/%20%22View%20the%20Self-Managed%20version%20of%20this%20component%22)

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

This output sends data to an [Arc](https://github.com/Basekick-Labs/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.

> 📝 **NOTE**
>
> 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

```yml
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)
```

#### Advanced

```yml
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)Fields

### [](#access_log_body_limit)`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)`access_log_level`

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

**Type**: `string`

**Default**: `""`

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

### [](#backoff)`backoff`

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

**Type**: `object`

### [](#backoff-initial_interval)`backoff.initial_interval`

Initial interval between retries on 429 responses.

**Type**: `string`

**Default**: `1s`

### [](#backoff-max_interval)`backoff.max_interval`

Maximum interval between retries on 429 responses.

**Type**: `string`

**Default**: `30s`

### [](#backoff-max_retries)`backoff.max_retries`

Maximum number of retries on 429 responses.

**Type**: `int`

**Default**: `3`

### [](#base_url)`base_url`

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

**Type**: `string`

### [](#batching)`batching`

Allows you to configure a [batching policy](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/batching/).

**Type**: `object`

```yaml
# 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)`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)`batching.check`

A [Bloblang query](https://docs.redpanda.com/cloud-data-platform/develop/connect/guides/bloblang/about/) that should return a boolean value indicating whether a message should end a batch.

**Type**: `string`

**Default**: `""`

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

### [](#batching-count)`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)`batching.period`

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

**Type**: `string`

**Default**: `""`

```yaml
# Examples:
period: 1s

# ---

period: 1m

# ---

period: 500ms
```

### [](#batching-processors)`batching.processors[]`

A list of [processors](https://docs.redpanda.com/cloud-data-platform/develop/connect/components/processors/about/) 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`

```yaml
# Examples:
processors:
  - archive:
      format: concatenate

# ---

processors:
  - archive:
      format: lines

# ---

processors:
  - archive:
      format: json_array
```

### [](#compression)`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)`database`

The target database name.

**Type**: `string`

**Default**: `default`

### [](#disable_http2)`disable_http2`

Disable HTTP/2 and force HTTP/1.1.

**Type**: `bool`

**Default**: `false`

### [](#format)`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`

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

**Type**: `object`

### [](#http-disable_compression)`http.disable_compression`

Disable automatic decompression of gzip responses.

**Type**: `bool`

**Default**: `false`

### [](#http-disable_keep_alives)`http.disable_keep_alives`

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

**Type**: `bool`

**Default**: `false`

### [](#http-expect_continue_timeout)`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.h2`

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

**Type**: `object`

### [](#http-h2-max_decoder_header_table_size)`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)`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)`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)`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)`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)`http.h2.ping_timeout`

Timeout waiting for a PING response before closing the connection.

**Type**: `string`

**Default**: `15s`

### [](#http-h2-send_ping_timeout)`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)`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)`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)`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)`http.max_conns_per_host`

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

**Type**: `int`

**Default**: `64`

### [](#http-max_idle_conns)`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)`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)`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)`http.max_response_header_bytes`

Maximum bytes of response headers to allow.

**Type**: `int`

**Default**: `1048576`

### [](#http-read_buffer_size)`http.read_buffer_size`

Size in bytes of the per-connection read buffer.

**Type**: `int`

**Default**: `4096`

### [](#http-response_header_timeout)`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)`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)`http.write_buffer_size`

Size in bytes of the per-connection write buffer.

**Type**: `int`

**Default**: `4096`

### [](#max_in_flight)`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)`measurement`

The measurement (table) name. Supports interpolation functions.

**Type**: `string`

```yaml
# Examples:
measurement: cpu_metrics

# ---

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

# ---

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

### [](#proxy_url)`proxy_url`

HTTP proxy URL. Empty string disables proxying.

**Type**: `string`

**Default**: `""`

### [](#tags_mapping)`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`

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

### [](#tcp)`tcp`

TCP socket configuration.

**Type**: `object`

### [](#tcp-connect_timeout)`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`

TCP keep-alive probe configuration.

**Type**: `object`

### [](#tcp-keep_alive-count)`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)`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)`tcp.keep_alive.interval`

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

**Type**: `string`

**Default**: `15s`

### [](#tcp-tcp_user_timeout)`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)`timeout`

HTTP request timeout.

**Type**: `string`

**Default**: `5s`

### [](#timestamp_field)`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)`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)`tls`

Custom TLS settings can be used to override system defaults.

**Type**: `object`

### [](#tls-client_certs)`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**: `[]`

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

# ---

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

### [](#tls-client_certs-cert)`tls.client_certs[].cert`

A plain text certificate to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-cert_file)`tls.client_certs[].cert_file`

The path of a certificate to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-key)`tls.client_certs[].key`

A plain text certificate key to use.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-key_file)`tls.client_certs[].key_file`

The path of a certificate key to use.

**Type**: `string`

**Default**: `""`

### [](#tls-client_certs-password)`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.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

```yaml
# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}
```

### [](#tls-enable_renegotiation)`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)`tls.enabled`

Whether custom TLS settings are enabled.

**Type**: `bool`

**Default**: `false`

### [](#tls-root_cas)`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.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

**Default**: `""`

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

### [](#tls-root_cas_file)`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**: `""`

```yaml
# Examples:
root_cas_file: ./root_cas.pem
```

### [](#tls-skip_cert_verify)`tls.skip_cert_verify`

Whether to skip server side certificate verification.

**Type**: `bool`

**Default**: `false`

### [](#token)`token`

Bearer token for authentication.

> ⚠️ **CAUTION**
>
> This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see [Manage Secrets](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/secret-management/) before adding it to your configuration.

**Type**: `string`

### [](#tps_burst)`tps_burst`

Maximum burst size for rate limiting.

**Type**: `int`

**Default**: `1`

### [](#tps_limit)`tps_limit`

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

**Type**: `float`

**Default**: `0`

## [](#performance)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](https://docs.redpanda.com/cloud-data-platform/develop/connect/configuration/batching/).