otlp_grpc

Receive OpenTelemetry traces, logs, and metrics via OTLP/gRPC protocol.

Introduced in version 4.78.0.

Exposes an OpenTelemetry Collector gRPC receiver that accepts traces, logs, and metrics via gRPC.

Telemetry data is received in OTLP protobuf format and converted to individual Redpanda OTEL v1 protobuf messages. Each signal (span, log record, or metric) becomes a separate message with embedded Resource and Scope metadata, optimized for Kafka partitioning.

  • Common

  • Advanced

inputs:
  label: ""
  otlp_grpc:
    encoding: json
    address: 0.0.0.0:4317
    rate_limit: ""
inputs:
  label: ""
  otlp_grpc:
    encoding: json
    address: 0.0.0.0:4317
    tls:
      enabled: false
      cert_file: ""
      key_file: ""
    auth_token: ""
    max_recv_msg_size: 4194304
    rate_limit: ""
    tcp:
      reuse_addr: false
      reuse_port: false
    schema_registry:
      url: "" # No default (required)
      timeout: 5s
      tls:
        enabled: false
        skip_cert_verify: false
        enable_renegotiation: false
        root_cas: ""
        root_cas_file: ""
        client_certs: []
      oauth:
        enabled: false
        consumer_key: ""
        consumer_secret: ""
        access_token: ""
        access_token_secret: ""
      basic_auth:
        enabled: false
        username: ""
        password: ""
      jwt:
        enabled: false
        private_key_file: ""
        signing_method: ""
        claims: {}
        headers: {}
      common_subject: ""
      trace_subject: ""
      log_subject: ""
      metric_subject: ""

Protocols

This input supports OTLP/gRPC on the default port 4317 using the standard OTLP protobuf format for all signal types (traces, logs, metrics).

Output format

Each OTLP export request is unbatched into individual messages:

  • Traces: One message per span

  • Logs: One message per log record

  • Metrics: One message per metric

Messages are encoded in Redpanda OTEL v1 protobuf format.

Metadata

This input adds the following metadata fields to each message:

  • signal_type - The signal type: "trace", "log", or "metric"

You can access these metadata fields using function interpolation.

Authentication

When auth_token is configured, clients must include the token in the gRPC metadata.

Go client example

import (
    "go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
)

exporter, err := otlptracegrpc.New(ctx,
    otlptracegrpc.WithEndpoint("localhost:4317"),
    otlptracegrpc.WithInsecure(), // or WithTLSCredentials() for TLS
    otlptracegrpc.WithHeaders(map[string]string{
        "authorization": "Bearer your-token-here",
    }),
)

Environment variable

export OTEL_EXPORTER_OTLP_HEADERS="authorization=Bearer your-token-here"

Rate limiting

An optional rate limit resource can be specified to throttle incoming requests. When the rate limit is breached, requests will receive a ResourceExhausted gRPC status code.

Fields

address

The address to listen on for gRPC connections.

Type: string

Default: 0.0.0.0:4317

auth_token

Optional bearer token for authentication. When set, requests must include 'authorization: Bearer <token>' metadata.

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

Type: string

Default: ""

encoding

Encoding format for messages in the batch. Options: 'protobuf' or 'json'.

Type: string

Default: json

Options: protobuf, json

max_recv_msg_size

Maximum size of gRPC messages to receive in bytes.

Type: int

Default: 4194304

rate_limit

An optional rate limit resource to throttle requests.

Type: string

Default: ""

schema_registry

Optional Schema Registry configuration for adding Schema Registry wire format headers to messages.

Type: object

schema_registry.basic_auth

Allows you to specify basic authentication.

Type: object

schema_registry.basic_auth.enabled

Whether to use basic authentication in requests.

Type: bool

Default: false

schema_registry.basic_auth.password

A password to authenticate with.

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

Type: string

Default: ""

schema_registry.basic_auth.username

A username to authenticate as.

Type: string

Default: ""

schema_registry.common_subject

Schema subject name for the common protobuf schema. Only used when encoding is 'protobuf'. Defaults to 'redpanda-otel-common' for protobuf encoding or 'redpanda-otel-common-json' for JSON encoding.

Type: string

Default: ""

schema_registry.jwt

Beta

Allows you to specify JWT authentication.

Type: object

schema_registry.jwt.claims

A value used to identify the claims that issued the JWT.

Type: object

Default: {}

schema_registry.jwt.enabled

Whether to use JWT authentication in requests.

Type: bool

Default: false

schema_registry.jwt.headers

Add optional key/value headers to the JWT.

Type: object

Default: {}

schema_registry.jwt.private_key_file

A file with the PEM encoded via PKCS1 or PKCS8 as private key.

Type: string

Default: ""

schema_registry.jwt.signing_method

A method used to sign the token such as RS256, RS384, RS512 or EdDSA.

Type: string

Default: ""

schema_registry.log_subject

Schema subject name for log data. Defaults to 'redpanda-otel-logs' for protobuf encoding or 'redpanda-otel-logs-json' for JSON encoding.

Type: string

Default: ""

schema_registry.metric_subject

Schema subject name for metric data. Defaults to 'redpanda-otel-metrics' for protobuf encoding or 'redpanda-otel-metrics-json' for JSON encoding.

Type: string

Default: ""

schema_registry.oauth

Allows you to specify open authentication via OAuth version 1.

Type: object

schema_registry.oauth.access_token

A value used to gain access to the protected resources on behalf of the user.

Type: string

Default: ""

schema_registry.oauth.access_token_secret

A secret provided in order to establish ownership of a given access token.

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

Type: string

Default: ""

schema_registry.oauth.consumer_key

A value used to identify the client to the service provider.

Type: string

Default: ""

schema_registry.oauth.consumer_secret

A secret used to establish ownership of the consumer key.

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

Type: string

Default: ""

schema_registry.oauth.enabled

Whether to use OAuth version 1 in requests.

Type: bool

Default: false

schema_registry.timeout

HTTP client timeout for Schema Registry requests.

Type: string

Default: 5s

schema_registry.tls

Custom TLS settings can be used to override system defaults.

Type: object

schema_registry.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

schema_registry.tls.client_certs[].cert

A plain text certificate to use.

Type: string

Default: ""

schema_registry.tls.client_certs[].cert_file

The path of a certificate to use.

Type: string

Default: ""

schema_registry.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 Secrets.

Type: string

Default: ""

schema_registry.tls.client_certs[].key_file

The path of a certificate key to use.

Type: string

Default: ""

schema_registry.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 Secrets.

Type: string

Default: ""

# Examples:
password: foo

# ---

password: ${KEY_PASSWORD}

schema_registry.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.

Requires version 3.45.0 or later.

Type: bool

Default: false

schema_registry.tls.enabled

Whether custom TLS settings are enabled.

Type: bool

Default: false

schema_registry.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 Secrets.

Type: string

Default: ""

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

schema_registry.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

schema_registry.tls.skip_cert_verify

Whether to skip server side certificate verification.

Type: bool

Default: false

schema_registry.trace_subject

Schema subject name for trace data. Defaults to 'redpanda-otel-traces' for protobuf encoding or 'redpanda-otel-traces-json' for JSON encoding.

Type: string

Default: ""

schema_registry.url

Schema Registry URL for schema operations.

Type: string

# Examples:
url: http://localhost:8081

tcp

TCP listener socket configuration.

Type: object

tcp.reuse_addr

Enable SO_REUSEADDR, allowing binding to ports in TIME_WAIT state. Useful for graceful restarts and config reloads where the server needs to rebind to the same port immediately after shutdown.

Type: bool

Default: false

tcp.reuse_port

Enable SO_REUSEPORT, allowing multiple sockets to bind to the same port for load balancing across multiple processes/threads.

Type: bool

Default: false

tls

TLS configuration for gRPC.

Type: object

tls.cert_file

Path to the TLS certificate file.

Type: string

Default: ""

tls.enabled

Enable TLS connections.

Type: bool

Default: false

tls.key_file

Path to the TLS key file.

Type: string

Default: ""