kafka_franz

A Kafka output using the Franz Kafka client library.

Introduced in version 3.61.0.

Common
Advanced

# Common config fields, showing default values
output:
  label: ""
  kafka_franz:
    seed_brokers: [] # No default (required)
    topic: "" # No default (required)
    key: "" # No default (optional)
    partition: ${! meta("partition") } # No default (optional)
    metadata:
      include_prefixes: []
      include_patterns: []
    max_in_flight: 10
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""

# Advanced config fields, showing default values
output:
  label: ""
  kafka_franz:
    seed_brokers: [] # No default (required)
    topic: "" # No default (required)
    key: "" # No default (optional)
    partitioner: "" # No default (optional)
    partition: ${! meta("partition") } # No default (optional)
    client_id: benthos
    rack_id: ""
    idempotent_write: true
    metadata:
      include_prefixes: []
      include_patterns: []
    max_in_flight: 10
    timeout: 10s
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: [] # No default (optional)
    max_message_bytes: 1MB
    broker_write_max_bytes: 100MB
    compression: "" # No default (optional)
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    sasl: [] # No default (optional)
    timestamp: ${! timestamp_unix() } # No default (optional)

Writes a batch of messages to Kafka brokers and waits for acknowledgement before propagating it back to the input.

This output often out-performs the traditional kafka output as well as providing more useful logs and error messages.

Fields

`seed_brokers`

A list of broker addresses to connect to in order to establish connections. If an item of the list contains commas it will be expanded into multiple addresses.

Type: array

# Examples

seed_brokers:
  - localhost:9092

seed_brokers:
  - foo:9092
  - bar:9092

seed_brokers:
  - foo:9092,bar:9092

`topic`

A topic to write messages to. This field supports interpolation functions.

Type: string

`key`

An optional key to populate for each message. This field supports interpolation functions.

Type: string

`partitioner`

Override the default murmur2 hashing partitioner.

Type: string

Option	Summary
`least_backup`	Chooses the least backed up partition (the partition with the fewest amount of buffered records). Partitions are selected per batch.
`manual`	Manually select a partition for each message, requires the field `partition` to be specified.
`murmur2_hash`	Kafka’s default hash algorithm that uses a 32-bit murmur2 hash of the key to compute which partition the record will be on.
`round_robin`	Round-robin’s messages through all available partitions. This algorithm has lower throughput and causes higher CPU load on brokers, but can be useful if you want to ensure an even distribution of records to partitions.

`partition`

An optional explicit partition to set for each message. This field is only relevant when the partitioner is set to manual. The provided interpolation string must be a valid integer. This field supports interpolation functions.

Type: string

# Examples

partition: ${! meta("partition") }

`client_id`

An identifier for the client connection.

Type: string

Default: "benthos"

`rack_id`

A rack identifier for this client.

Type: string

Default: ""

`idempotent_write`

Enable the idempotent write producer option. This requires the IDEMPOTENT_WRITE permission on CLUSTER and can be disabled if this permission is not available.

Type: bool

Default: true

`metadata`

Determine which (if any) metadata values should be added to messages as headers.

Type: object

`metadata.include_prefixes`

Provide a list of explicit metadata key prefixes to match against.

Type: array

Default: []

# Examples

include_prefixes:
  - foo_
  - bar_

include_prefixes:
  - kafka_

include_prefixes:
  - content-

`metadata.include_patterns`

Provide a list of explicit metadata key regular expression (re2) patterns to match against.

Type: array

Default: []

# Examples

include_patterns:
  - .*

include_patterns:
  - _timestamp_unix$

`max_in_flight`

The maximum number of batches to be sending in parallel at any given time.

Type: int

Default: 10

`timeout`

The maximum period of time to wait for message sends before abandoning the request and retrying

Type: string

Default: "10s"

`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.count`

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

Type: int

Default: 0

`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.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.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.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: array

# Examples

processors:
  - archive:
      format: concatenate

processors:
  - archive:
      format: lines

processors:
  - archive:
      format: json_array

`max_message_bytes`

The maximum space in bytes than an individual message may take, messages larger than this value will be rejected. This field corresponds to Kafka’s max.message.bytes.

Type: string

Default: "1MB"

# Examples

max_message_bytes: 100MB

max_message_bytes: 50mib

`broker_write_max_bytes`

The upper bound for the number of bytes written to a broker connection in a single write. This field corresponds to Kafka’s socket.request.max.bytes.

Type: string

Default: "100MB"

# Examples

broker_write_max_bytes: 128MB

broker_write_max_bytes: 50mib

`compression`

Optionally set an explicit compression type. The default preference is to use snappy when the broker supports it, and fall back to none if not.

Type: string

Options: lz4 , snappy , gzip , none , zstd .

`tls`

Custom TLS settings can be used to override system defaults.

Type: object

`tls.enabled`

Whether custom TLS settings are enabled.

Type: bool

Default: false

`tls.skip_cert_verify`

Whether to skip server side certificate verification.

Type: bool

Default: false

`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 Requires version 3.45.0 or newer

`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.

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.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: array

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[].key`

A plain text certificate key to use.

Type: string

Default: ""

`tls.client_certs[].cert_file`

The path of a certificate to use.

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.

Type: string

Default: ""

# Examples

password: foo

password: ${KEY_PASSWORD}

`sasl`

Specify one or more methods of SASL authentication. SASL is tried in order; if the broker supports the first mechanism, all connections will use that mechanism. If the first mechanism fails, the client will pick the first supported mechanism. If the broker does not support any client mechanisms, connections will fail.

Type: array

# Examples

sasl:
  - mechanism: SCRAM-SHA-512
    password: bar
    username: foo

`sasl[].mechanism`

The SASL mechanism to use.

Type: string

Option	Summary
`AWS_MSK_IAM`	AWS IAM based authentication as specified by the ‘aws-msk-iam-auth’ java library.
`OAUTHBEARER`	OAuth Bearer based authentication.
`PLAIN`	Plain text authentication.
`SCRAM-SHA-256`	SCRAM based authentication as specified in RFC5802.
`SCRAM-SHA-512`	SCRAM based authentication as specified in RFC5802.
`none`	Disable sasl authentication

`sasl[].username`

A username to provide for PLAIN or SCRAM-* authentication.

Type: string

Default: ""

`sasl[].password`

A password to provide for PLAIN or SCRAM-* authentication.

Type: string

Default: ""

`sasl[].token`

The token to use for a single session’s OAUTHBEARER authentication.

Type: string

Default: ""

`sasl[].extensions`

Key/value pairs to add to OAUTHBEARER authentication requests.

Type: object

`sasl[].aws`

Contains AWS specific fields for when the mechanism is set to AWS_MSK_IAM.

Type: object

`sasl[].aws.region`

The AWS region to target.

Type: string

Default: ""

`sasl[].aws.endpoint`

Allows you to specify a custom endpoint for the AWS API.

Type: string

Default: ""

`sasl[].aws.credentials`

Optional manual configuration of AWS credentials to use. More information can be found in xref:guides:cloud/aws.adoc[].

Type: object

`sasl[].aws.credentials.profile`

A profile from ~/.aws/credentials to use.

Type: string

Default: ""

`sasl[].aws.credentials.id`

The ID of credentials to use.

Type: string

Default: ""

`sasl[].aws.credentials.secret`

The secret for the credentials being used.

Type: string

Default: ""

`sasl[].aws.credentials.token`

The token for the credentials being used, required when using short term credentials.

Type: string

Default: ""

`sasl[].aws.credentials.from_ec2_role`

Use the credentials of a host EC2 machine configured to assume an IAM role associated with the instance.

Type: bool

Default: false Requires version 4.2.0 or newer

`sasl[].aws.credentials.role`

A role ARN to assume.

Type: string

Default: ""

`sasl[].aws.credentials.role_external_id`

An external ID to provide when assuming a role.

Type: string

Default: ""

`timestamp`

An optional timestamp to set for each message. When left empty, the current timestamp is used. This field supports interpolation functions.

Type: string

# Examples

timestamp: ${! timestamp_unix() }

timestamp: ${! metadata("kafka_timestamp_unix") }