redpanda
Consumes topic data from one or more Kafka brokers.
Introduced in version 4.39.0.
If you intend to use multiple redpanda components in your data pipeline, which have a common set of credentials, consider using the redpanda_common input and output instead.
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Common
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Advanced
# Common configuration fields, showing default values
input:
label: ""
redpanda:
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
# All configuration fields, showing default values
input:
label: "" # No default (optional)
redpanda:
seed_brokers: [] # No default (required)
client_id: benthos
tls:
enabled: false
skip_cert_verify: false
enable_renegotiation: false
root_cas: "" # No default (optional)
root_cas_file: "" # No default (optional)
client_certs: [] # No default (optional)
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: "" # No default (optional)
instance_id: "" # No default (optional)
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)
commit_period: 5s
partition_buffer_bytes: 1MB
topic_lag_refresh_period: 5s
auto_replay_nacks: true
Consumer groups
When you specify a consumer group in your configuration, this input consumes one or more topics and automatically balances the topic partitions across any other connected clients with the same consumer group. Otherwise, topics are consumed in their entirety or with explicit partitions.
Delivery guarantees
If you choose to use consumer groups, the offsets of records received by Redpanda Connect are committed automatically. In the event of restarts, this input uses the committed offsets to resume data consumption where it left off.
Redpanda Connect guarantees at-least-once delivery. Records are only confirmed as delivered when all downstream outputs that a record is routed to have also confirmed delivery.
Ordering
To preserve the order of topic partitions:
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Records consumed from each partition are processed and delivered in the order that they are received
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Only one batch of records of a given partition is processed at a time
This approach means that although records from different partitions may be processed in parallel, records from the same partition are processed in sequential order.
Delivery errors
The order in which records are delivered may be disrupted by delivery errors and any error-handling mechanisms that start up. Redpanda Connect leans towards at-least-once delivery unless instructed otherwise, and this includes reattempting delivery of data when the ordering of that data is no longer guaranteed.
For example, a batch of records is sent to an output broker and only a subset of records are delivered. In this scenario, Redpanda Connect (by default) attempts to deliver the records that failed, even though these delivery failures may have been sent before records that were delivered successfully.
Use a fallback output
To prevent delivery errors from disrupting the order of records, you must specify a fallback
output in your pipeline configuration. When adding a fallback
output, it is good practice to set the auto_retry_nacks
field to false
. This also improves the throughput of your pipeline.
For example, the following configuration includes a fallback
output. If Redpanda Connect fails to write delivery errors to the foo
topic, it then attempts to write them into a dead letter queue topic (foo_dlq
), which is retried indefinitely as a way to apply back pressure.
output:
fallback:
- redpanda_common:
topic: foo
- retry:
output:
redpanda_common:
topic: foo_dlq
Batching
Records are processed and delivered from each partition in the same batches as they are received from brokers. Batch sizes are dynamically sized in order to optimize throughput, but you can tune them further using the following configuration fields:
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fetch_max_partition_bytes
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fetch_max_bytes
You can break batches down further using the split
processor.
Metrics
This input emits a redpanda_lag
metric with topic
and partition
labels for each consumed topic. The metric records the number of produced messages that remain to be read from each topic/partition pair by the specified consumer group.
Metadata
This input adds the following metadata fields to each message:
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kafka_key
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kafka_topic
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kafka_partition
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kafka_offset
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kafka_lag
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kafka_timestamp_ms
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kafka_timestamp_unix
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kafka_tombstone_message
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All record headers
Fields
auto_replay_nacks
Whether to automatically replay messages that are rejected (nacked) at the output level. If the cause of rejections is persistent, leaving this option enabled can result in back pressure.
Set auto_replay_nacks
to false
to delete rejected messages. Disabling auto replays can greatly improve memory efficiency of high throughput streams, as the original shape of the data is discarded immediately upon consumption and mutation.
Type: bool
Default: true
commit_period
The period of time between each commit of the current partition offsets. Offsets are always committed during shutdown.
Type: string
Default: 5s
conn_idle_timeout
Define how long connections can remain idle before they are closed.
Type: string
Default: 20s
consumer_group
An optional consumer group. When this value is specified:
-
The partitions of any topics, specified in the
topics
field, are automatically distributed across consumers sharing a consumer group -
Partition offsets are automatically committed and resumed under this name
Consumer groups are not supported when you specify explicit partitions to consume from in the topics
field.
Type: string
fetch_max_bytes
The maximum number of bytes that a broker tries to send during a fetch.
If individual records are larger than the fetch_max_bytes
value, brokers will still send them.
Type: string
Default: 50MiB
fetch_max_partition_bytes
The maximum number of bytes that are consumed from a single partition in a fetch request. This field is equivalent to the Java setting fetch.max.partition.bytes
.
If a single batch is larger than the fetch_max_partition_bytes
value, the batch is still sent so that the client can make progress.
Type: string
Default: 1MiB
fetch_max_wait
The maximum period of time a broker can wait for a fetch response to reach the required minimum number of bytes (fetch_min_bytes
).
Type: string
Default: 5s
fetch_min_bytes
The minimum number of bytes that a broker tries to send during a fetch. This field is equivalent to the Java setting fetch.min.bytes
.
Type: string
Default: 1B
heartbeat_interval
When you specify a consumer_group
, heartbeat_interval
sets how frequently a consumer group member should send heartbeats to Apache Kafka. Apache Kafka uses heartbeats to make sure that a group member’s session is active.
You must set heartbeat_interval
to less than one-third of session_timeout
.
This field is equivalent to the Java heartbeat.interval.ms
setting.
client
Type: string
Default: 3s
instance_id
When you specify a consumer_group
, assign a unique value to instance_id
to define the group’s static membership, which can prevent unnecessary rebalances during reconnections.
When you assign an instance ID, the client does not automatically leave the consumer group when it disconnects. To remove the client, you must use an external admin command on behalf of the instance ID.
Type: string
Default: ""
max_yield_batch_bytes
The maximum size (in bytes) for each batch yielded by this input. When routed to a redpanda output without modification this would roughly translate to the batch.bytes config field of a traditional producer.
Type: string
Default: 32KB
metadata_max_age
The maximum period of time after which metadata is refreshed.
Type: string
Default: 5m
partition_buffer_bytes
A buffer size (in bytes) for each consumed partition, which allows the internal queuing of records before they are flushed. Increasing this value may improve throughput but results in higher memory utilization.
Each buffer can grow slightly beyond this value.
Type: string
Default: 1MB
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: ""
rebalance_timeout
When you specify a consumer_group
, rebalance_timeout
sets a time limit for all consumer group members to complete their work and commit offsets after a rebalance has begun. The timeout excludes the time taken to detect a failed or late heartbeat, which indicates a rebalance is required.
Type: string
Default: 45s
regexp_topics
Whether listed topics are 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
request_timeout_overhead
Grants an additional buffer or overhead to requests that have timeout fields defined. This field is based on the behavior of Apache Kafka’s request.timeout.ms
parameter.
Type: string
Default: 10s
sasl[]
Specify one or more methods or mechanisms of SASL authentication. They are tried in order. If the broker supports the first SASL mechanism, all connections use it. If the first mechanism fails, the client picks the first supported mechanism. If the broker does not support any client mechanisms, all connections fail.
Type: object
# Examples:
sasl:
- mechanism: SCRAM-SHA-512
password: bar
username: foo
sasl[].aws.credentials
Optional manual configuration of AWS credentials to use. More information can be found in Amazon Web Services.
Type: object
sasl[].aws.credentials.from_ec2_role
Use the credentials of a host EC2 machine configured to assume an IAM role associated with the instance.
Requires version 4.2.0 or later.
Type: bool
sasl[].aws.credentials.role_external_id
An external ID to provide when assuming a role.
Type: string
sasl[].aws.credentials.secret
The secret for the credentials being used.
This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets. |
Type: string
sasl[].aws.credentials.token
The token for the credentials being used, required when using short term credentials.
Type: string
sasl[].mechanism
The SASL mechanism to use.
Type: string
Option | Summary |
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AWS IAM based authentication as specified by the 'aws-msk-iam-auth' java library. |
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OAuth Bearer based authentication. |
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Plain text authentication. |
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SCRAM based authentication as specified in RFC5802. |
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SCRAM based authentication as specified in RFC5802. |
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Disable sasl authentication |
sasl[].password
A password to provide for PLAIN or SCRAM-* authentication.
This field contains sensitive information that usually shouldn’t be added to a configuration directly. For more information, see Secrets. |
Type: string
Default: ""
sasl[].token
The token to use for a single session’s OAUTHBEARER authentication.
Type: string
Default: ""
seed_brokers[]
A list of broker addresses to connect to in order. Use commas to separate multiple addresses in a single list item.
Type: array
# Examples:
seed_brokers:
- "localhost:9092"
- "foo:9092"
- "bar:9092"
- "foo:9092,bar:9092"
session_timeout
When you specify a consumer_group
, session_timeout
sets the maximum interval between heartbeats sent by a consumer group member to the broker. If a broker doesn’t receive a heartbeat from a group member before the timeout expires, it removes the member from the consumer group and initiates a rebalance.
broker
Type: string
Default: 1m
start_offset
Specify the offset from which this input starts or restarts consuming messages. Restarts occur when the OffsetOutOfRange
error is seen during a fetch.
Type: string
Default: earliest
Option | Summary |
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Prevents consuming a partition in a group if the partition has no prior commits. Corresponds to Kafka’s |
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Start from the earliest offset. Corresponds to Kafka’s |
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Start from the latest offset. Corresponds to Kafka’s |
tls.client_certs[]
A list of client certificates to use. For each certificate specify values for either the cert
and key
fields, or cert_file
and key_file
fields.
Type: object
Default: []
# Examples:
client_certs:
- cert: foo
key: bar
- cert_file: ./example.pem
key_file: ./example.key
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: ""
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}
tls.enable_renegotiation
Whether to allow the remote server to 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
tls.root_cas
Specify a certificate authority to use (optional). This is a string that represents a certificate chain from the parent trusted root certificate, through 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-----
tls.root_cas_file
Specify the path to a root certificate authority file (optional). This is a file, often with a .pem
extension, which contains a certificate chain from the parent trusted root certificate, through 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
topic_lag_refresh_period
The interval between refresh cycles. During each cycle, this input queries the Redpanda Connect server to calculate the topic lag - the number of produced messages that remain to be read from each topic/partition pair by the specified consumer group.
Type: string
Default: 5s
topics[]
A list of topics to consume from. Use commas to separate multiple topics 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, you can specify explicit partitions to consume by using a colon after the topic name. For example, foo:0
would consume the partition 0
of the topic foo. This syntax supports ranges. For example, foo:0-10
would consume partitions 0
through to 10
inclusive.
It is also possible to specify an explicit offset to consume from by adding another colon after the partition. For example, 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_offset
determines which offset to start from.
Type: array
# Examples:
topics:
- foo
- bar
- things.*
- "foo,bar"
- "foo:0"
- "bar:1"
- "bar:3"
- "foo:0,bar:1,bar:3"
- "foo:0-5"