Kafka

Kafka source connector

Description

Source connector for Apache Kafka.

Key features

• batch
• stream
• exactly-once
• schema projection
• parallelism
• support user-defined split

Options

name	type	required	default value
topic	String	yes	-
bootstrap.servers	String	yes	-
pattern	Boolean	no	false
consumer.group	String	no	SeaTunnel-Consumer-Group
commit_on_checkpoint	Boolean	no	true
kafka.*	String	no	-
common-options	config	no	-
schema		no	-
format	String	no	json
field_delimiter	String	no	,
start_mode	String	no	group_offsets
start_mode.offsets		no
start_mode.timestamp	Long	no
partition-discovery.interval-millis	long	no	-1

topic [string]

Kafka topic name. If there are multiple topics, use , to split, for example: "tpc1,tpc2".

bootstrap.servers [string]

Kafka cluster address, separated by ",".

pattern [boolean]

If pattern is set to true,the regular expression for a pattern of topic names to read from. All topics in clients with names that match the specified regular expression will be subscribed by the consumer.

consumer.group [string]

Kafka consumer group id, used to distinguish different consumer groups.

commit_on_checkpoint [boolean]

If true the consumer's offset will be periodically committed in the background.

partition-discovery.interval-millis [long]

The interval for dynamically discovering topics and partitions.

kafka.* [string]

In addition to the above necessary parameters that must be specified by the Kafka consumer client, users can also specify multiple consumer client non-mandatory parameters, covering all consumer parameters specified in the official Kafka document.

The way to specify parameters is to add the prefix kafka. to the original parameter name. For example, the way to specify auto.offset.reset is: kafka.auto.offset.reset = latest . If these non-essential parameters are not specified, they will use the default values given in the official Kafka documentation.

common-options [config]

Source plugin common parameters, please refer to Source Common Options for details.

schema

The structure of the data, including field names and field types.

format

Data format. The default format is json. Optional text format. The default field separator is ", ". If you customize the delimiter, add the "field_delimiter" option.

field_delimiter

Customize the field delimiter for data format.

start_mode

The initial consumption pattern of consumers,there are several types: [earliest],[group_offsets],[latest],[specific_offsets],[timestamp]

start_mode.timestamp

The time required for consumption mode to be timestamp.

start_mode.offsets

The offset required for consumption mode to be specific_offsets.

for example:

   start_mode.offsets = {
            info-0 = 70
            info-1 = 10
            info-2 = 10
         }

Example

Simple

source {

  Kafka {
    result_table_name = "kafka_name"
    schema = {
      fields {
        name = "string"
        age = "int"
      }
    }
    format = text
    field_delimiter = "#“
    topic = "topic_1,topic_2,topic_3"
    bootstrap.servers = "localhost:9092"
    kafka.max.poll.records = 500
    kafka.client.id = client_1
  }
  
}

Regex Topic

source {

    Kafka {
          topic = ".*seatunnel*."
          pattern = "true" 
          bootstrap.servers = "localhost:9092"
          consumer.group = "seatunnel_group"
    }

}

AWS MSK SASL/SCRAM

Replace the following ${username} and ${password} with the configuration values in AWS MSK.

source {
    Kafka {
        topic = "seatunnel"
        bootstrap.servers = "xx.amazonaws.com.cn:9096,xxx.amazonaws.com.cn:9096,xxxx.amazonaws.com.cn:9096"
        consumer.group = "seatunnel_group"
        kafka.security.protocol=SASL_SSL
        kafka.sasl.mechanism=SCRAM-SHA-512
        kafka.sasl.jaas.config="org.apache.kafka.common.security.scram.ScramLoginModule required \nusername=${username}\npassword=${password};"
        #kafka.security.protocol=SASL_SSL
        #kafka.sasl.mechanism=AWS_MSK_IAM
        #kafka.sasl.jaas.config="software.amazon.msk.auth.iam.IAMLoginModule required;"
        #kafka.sasl.client.callback.handler.class="software.amazon.msk.auth.iam.IAMClientCallbackHandler"
    }
}

AWS MSK IAM

Download aws-msk-iam-auth-1.1.5.jar from https://github.com/aws/aws-msk-iam-auth/releases and put it in $SEATUNNEL_HOME/plugin/kafka/lib dir.

Please ensure the IAM policy have "kafka-cluster:Connect",. Like this:

"Effect": "Allow",
"Action": [
    "kafka-cluster:Connect",
    "kafka-cluster:AlterCluster",
    "kafka-cluster:DescribeCluster"
],

Source Config

source {
    Kafka {
        topic = "seatunnel"
        bootstrap.servers = "xx.amazonaws.com.cn:9098,xxx.amazonaws.com.cn:9098,xxxx.amazonaws.com.cn:9098"
        consumer.group = "seatunnel_group"
        #kafka.security.protocol=SASL_SSL
        #kafka.sasl.mechanism=SCRAM-SHA-512
        #kafka.sasl.jaas.config="org.apache.kafka.common.security.scram.ScramLoginModule required \nusername=${username}\npassword=${password};"
        kafka.security.protocol=SASL_SSL
        kafka.sasl.mechanism=AWS_MSK_IAM
        kafka.sasl.jaas.config="software.amazon.msk.auth.iam.IAMLoginModule required;"
        kafka.sasl.client.callback.handler.class="software.amazon.msk.auth.iam.IAMClientCallbackHandler"
    }
}

Changelog

2.3.0-beta 2022-10-20

• Add Kafka Source Connector

2.3.0 2022-12-30

• [Improve] Support setting read starting offset or time at startup config (3157)
• [Improve] Support for dynamic discover topic & partition in streaming mode (3125)