kafka_franz

A Kafka input using the Franz Kafka client library.

Introduced in version 3.61.0.

Common
Advanced

# Common config fields, showing default values
input:
  label: ""
  kafka_franz:
    seed_brokers: [] # No default (required)
    topics: [] # No default (required)
    regexp_topics: false
    transaction_isolation_level: read_uncommitted
    consumer_group: "" # No default (optional)
    auto_replay_nacks: true

# Advanced config fields, showing default values
input:
  label: ""
  kafka_franz:
    seed_brokers: [] # No default (required)
    client_id: benthos
    tls:
      enabled: false
      skip_cert_verify: false
      enable_renegotiation: false
      root_cas: ""
      root_cas_file: ""
      client_certs: []
    sasl: [] # No default (optional)
    metadata_max_age: 5m
    request_timeout_overhead: 10s
    conn_idle_timeout: 20s
    topics: [] # No default (required)
    regexp_topics: false
    rack_id: ""
    instance_id: ""
    rebalance_timeout: 45s
    session_timeout: 1m
    heartbeat_interval: 3s
    start_offset: earliest
    fetch_max_bytes: 50MiB
    fetch_max_wait: 5s
    fetch_min_bytes: 1B
    fetch_max_partition_bytes: 1MiB
    transaction_isolation_level: read_uncommitted
    consumer_group: "" # No default (optional)
    checkpoint_limit: 1024
    commit_period: 5s
    multi_header: false
    batching:
      count: 0
      byte_size: 0
      period: ""
      check: ""
      processors: [] # No default (optional)
    topic_lag_refresh_period: 5s
    auto_replay_nacks: true

When a consumer group is specified this input consumes one or more topics where partitions will automatically balance across any other connected clients with the same consumer group. When a consumer group is not specified topics can either be consumed in their entirety or with explicit partitions.

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

Metadata

This input adds the following metadata fields to each message:

- kafka_key
- kafka_topic
- kafka_partition
- kafka_offset
- kafka_lag
- kafka_timestamp_ms
- kafka_timestamp_unix
- kafka_tombstone_message
- All record headers

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

`client_id`

An identifier for the client connection.

Type: string

Default: "benthos"

`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

`sasl[].aws.endpoint`

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

Type: string

`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

`sasl[].aws.credentials.id`

The ID of credentials to use.

Type: string

`sasl[].aws.credentials.secret`

The secret for the credentials being used.

Type: string

`sasl[].aws.credentials.token`

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

Type: string

`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

Requires version 4.2.0 or newer

`sasl[].aws.credentials.role`

A role ARN to assume.

Type: string

`sasl[].aws.credentials.role_external_id`

An external ID to provide when assuming a role.

Type: string

`metadata_max_age`

The maximum age of metadata before it is refreshed.

Type: string

Default: "5m"

`request_timeout_overhead`

The request time overhead. Uses the given time as overhead while deadlining requests. Roughly equivalent to request.timeout.ms, but grants additional time to requests that have timeout fields.

Type: string

Default: "10s"

`conn_idle_timeout`

The rough amount of time to allow connections to idle before they are closed.

Type: string

Default: "20s"

`topics`

A list of topics to consume from. Multiple comma separated topics can be listed in a single element. When a consumer_group is specified partitions are automatically distributed across consumers of a topic, otherwise all partitions are consumed.

Alternatively, it’s possible to specify explicit partitions to consume from with a colon after the topic name, e.g. foo:0 would consume the partition 0 of the topic foo. This syntax supports ranges, e.g. foo:0-10 would consume partitions 0 through to 10 inclusive.

Finally, it’s also possible to specify an explicit offset to consume from by adding another colon after the partition, e.g. foo:0:10 would consume the partition 0 of the topic foo starting from the offset 10. If the offset is not present (or remains unspecified) then the field start_from_oldest determines which offset to start from.

Type: array

# Examples

topics:
  - foo
  - bar

topics:
  - things.*

topics:
  - foo,bar

topics:
  - foo:0
  - bar:1
  - bar:3

topics:
  - foo:0,bar:1,bar:3

topics:
  - foo:0-5

`regexp_topics`

Whether listed topics should be interpreted as regular expression patterns for matching multiple topics. When topics are specified with explicit partitions this field must remain set to false.

Type: bool

Default: false

`rack_id`

A rack specifies where the client is physically located and changes fetch requests to consume from the closest replica as opposed to the leader replica.

Type: string

Default: ""

`instance_id`

When using a consumer group, an instance ID specifies the groups static membership, which can prevent rebalances during reconnects. When using a instance ID the client does NOT leave the group when closing. To actually leave the group one must use an external admin command to leave the group on behalf of this instance ID. This ID must be unique per consumer within the group.

Type: string

Default: ""

`rebalance_timeout`

When using a consumer group, rebalance_timeout sets how long group members are allowed to take when a rebalance has begun. This timeout is how long all members are allowed to complete work and commit offsets, minus the time it took to detect the rebalance (from a heartbeat).

Type: string

Default: "45s"

`session_timeout`

When using a consumer group, session_timeout sets how long a member in hte group can go between heartbeats. If a member does not heartbeat in this timeout, the broker will remove the member from the group and initiate a rebalance.

Type: string

Default: "1m"

`heartbeat_interval`

When using a consumer group, heartbeat_interval sets how long a group member goes between heartbeats to Kafka. Kafka uses heartbeats to ensure that a group member’s sesion stays active. This value should be no higher than 1/3rd of the session_timeout. This is equivalent to the Java heartbeat.interval.ms setting.

Type: string

Default: "3s"

`start_offset`

Sets the offset to start consuming from, or if OffsetOutOfRange is seen while fetching, to restart consuming from.

Type: string

Default: "earliest"

Option	Summary
`committed`	Prevents consuming a partition in a group if the partition has no prior commits. Corresponds to Kafka’s `auto.offset.reset=none` option
`earliest`	Start from the earliest offset. Corresponds to Kafka’s `auto.offset.reset=earliest` option.
`latest`	Start from the latest offset. Corresponds to Kafka’s `auto.offset.reset=latest` option.

`fetch_max_bytes`

Sets the maximum amount of bytes a broker will try to send during a fetch. Note that brokers may not obey this limit if it has records larger than this limit. This is the equivalent to the Java fetch.max.bytes setting.

Type: string

Default: "50MiB"

`fetch_max_wait`

Sets the maximum amount of time a broker will wait for a fetch response to hit the minimum number of required bytes. This is the equivalent to the Java fetch.max.wait.ms setting.

Type: string

Default: "5s"

`fetch_min_bytes`

Sets the minimum amount of bytes a broker will try to send during a fetch. This is the equivalent to the Java fetch.min.bytes setting.

Type: string

Default: "1B"

`fetch_max_partition_bytes`

Sets the maximum amount of bytes that will be consumed for a single partition in a fetch request. Note that if a single batch is larger than this number, that batch will still be returned so the client can make progress. This is the equivalent to the Java fetch.max.partition.bytes setting.

Type: string

Default: "1MiB"

`transaction_isolation_level`

The transaction isolation level

Type: string

Default: "read_uncommitted"

Option	Summary
`read_committed`	If set, only committed transactional records are processed.
`read_uncommitted`	If set, then uncommitted records are processed.

`consumer_group`

An optional consumer group to consume as. When specified the partitions of specified topics are automatically distributed across consumers sharing a consumer group, and partition offsets are automatically committed and resumed under this name. Consumer groups are not supported when specifying explicit partitions to consume from in the topics field.

Type: string

`checkpoint_limit`

Determines how many messages of the same partition can be processed in parallel before applying back pressure. When a message of a given offset is delivered to the output the offset is only allowed to be committed when all messages of prior offsets have also been delivered, this ensures at-least-once delivery guarantees. However, this mechanism also increases the likelihood of duplicates in the event of crashes or server faults, reducing the checkpoint limit will mitigate this.

Type: int

Default: 1024

`commit_period`

The period of time between each commit of the current partition offsets. Offsets are always committed during shutdown.

Type: string

Default: "5s"

`multi_header`

Decode headers into lists to allow handling of multiple values with the same key

Type: bool

Default: false

`batching`

Allows you to configure a batching policy that applies to individual topic partitions in order to batch messages together before flushing them for processing. Batching can be beneficial for performance as well as useful for windowed processing, and doing so this way preserves the ordering of topic partitions.

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

`topic_lag_refresh_period`

The period of time between each topic lag refresh cycle.

Type: string

Default: "5s"

`auto_replay_nacks`

Whether messages that are rejected (nacked) at the output level should be automatically replayed indefinitely, eventually resulting in back pressure if the cause of the rejections is persistent. If set to false these messages will instead be deleted. Disabling auto replays can greatly improve memory efficiency of high throughput streams as the original shape of the data can be discarded immediately upon consumption and mutation.

Type: bool

Default: true