Kafka Sink Connector

Kafka Sink Connector integrates Kafka with GridGain 9, exporting topic data into GridGain tables.

Guarantees

GridGain Kafka sink provides the following guarantees:

At least once delivery.
Automatic failover and reconnection to GridGain cluster.
Message order within the same GridGain partition is preserved. Message order across different partitions is not defined.

Kafka Sink Configuration

Installation

Install the Kafka Sink connector (packaged together with the Kafka Source connector) following the recommended procedure.

Configuration

GridGain Kafka sink connector uses the standard Kafka configuration file to define configuration properties.

Below is the example of the configuration file:

name=gridgain-kafka-connect-sink
topics=topic1,topic2,topic3
connector.class=org.gridgain.kafka.sink.GridGainSinkConnector
tasks.max=1

ignite.addresses=host1:10800,host2:10800
ignite.operationTimeout=30000

ignite.table.name.regex=^events$
ignite.table.name.regex.replacement=Events
ignite.table.name.regex.1=.*
ignite.table.name.regex.replacement.1=UserEvents

Parameter Description Default value

Parameter	Description	Default value
name	The name of GridGain kafka connector.
topics	The list of topics that will be copied to GridGain.
connector.class	The class name of the GridGain Sink connector.
tasks.max	The maximum number of sink tasks running in parallel.
retry.backoff	The period of time before retrying the request, in milliseconds.	3000
nested.struct.mode	How nested STRUCT fields are handled. Possible values are: `CONCAT`, `FLATTEN`, `IGNORE`, `DISALLOW`.	CONCAT (separator defined in `nested.struct.concat.separator`)
nested.struct.concat.separator	The separator that is used to concatenate nested field names into Ignite column name when `nested.struct.mode` is set to `CONCAT`. For example, if separator is `_` and nested field is `address.street`, the column name will be `address_street`.	Underscore symbol (`_`)
flush.mode	Flush mode. Possible values are: `KAFKA` - Kafka decides when to flush, based on `offset.flush.interval.ms` configuration, `ON_PUT` - flush on every put. This causes more frequent flushes and may affect performance.	`KAFKA`
ignite.addresses	Required. Addresses of the GridGain nodes the data will be sent to.
ignite.authenticator.basic.password	Password for basic authentication to the GridGain cluster.
ignite.authenticator.basic.username	Username for basic authentication to the GridGain cluster.
ignite.background.reconnect.interval	Background reconnect interval in milliseconds. Set to 0 to disable background reconnect.
ignite.connect.timeout	Socket connection timeout, in milliseconds.	5000
ignite.error.handling.policy	Error handling policy. Supported values: `LOG_ONLY` - the entry will be skipped while writing the error to the log. `STOP_TASK` - the task will be stopped when the error happens. `DEAD_LETTER_QUEUE` - problematic records will be redirected to the configured Dead Letter Queue topic without stopping the processing.	`LOG_ONLY`
ignite.heartbeat.interval	An interval at which the client sends heartbeat messages to the cluster, in milliseconds. 0 disables heartbeats.	30000
ignite.heartbeat.timeout	Heartbeat response timeout, in milliseconds. The connection is closed if the response is not received before the timeout occurs.	5000
ignite.reconnect.interval	Reconnect interval, in milliseconds. 0 disables background reconnects.	30_000
ignite.ssl.client.authentication.mode	Client authentication mode: `NONE`, `OPTIONAL`, or `REQUIRE`.	`NONE`
ignite.ssl.ciphers	Comma-separated list of ciphers to be used to set up the SSL connection.
ignite.ssl.enabled	If true, an SSL/TLS connection is established.
ignite.ssl.key.store.password	Keystore password to be used to set up the SSL connection.
ignite.ssl.key.store.path	Keystore path to be used to set up the SSL connection.
ignite.ssl.trust.store.password	Truststore password to be used to set up the SSL connection.
ignite.ssl.trust.store.path	Truststore path to be used to set up the SSL connection.
ignite.streamer.auto.flush.interval	Ignite data streamer’s auto-flush interval. The interval, in milliseconds, after which the data streamer will automatically flush the data to the cluster.	5000
ignite.streamer.page.size	Ignite data streamer’s page size. The number of entries that will be sent to the cluster per network call.	1000
ignite.streamer.parallel.ops	Ignite data streamer’s parallel operations. The number of parallel operations per partition. Defines how many in-flight requests can be active per partition.	1
ignite.streamer.retry.limit	Ignite data streamer’s retry limit. The number of retries in case of a connection issue.	16
ignite.streamer.receiver.class.name	Specifies the fully qualified class name of the custom receiver to use with the streamer. The receiver must implement `DataStreamerReceiver<Tuple, Tuple, Void>` to ensure proper integration with the connector
ignite.streamer.receiver.deployment.units	Accepts a comma-separated list of deployment units in the format `name:version`. Use this property together with the `ignite.streamer.receiver.class.name` for the system to be able to find your receiver.
ignite.table.name.regex	The regular expression pattern that will be replaced in the topic name. See the examples below for how to use regular expressions.
ignite.table.name.regex.replacement	The value regular expression match will be replaced by.
ignite.table.name.regex.1	Optional ordering for regular expressions. Expressions with lower number will be applied first.
ignite.table.name.regex.replacement.1	Optional ordering for regular expressions. Expressions with lower number will be applied first.

name

The name of GridGain kafka connector.

topics

The list of topics that will be copied to GridGain.

connector.class

The class name of the GridGain Sink connector.

tasks.max

The maximum number of sink tasks running in parallel.

retry.backoff

The period of time before retrying the request, in milliseconds.

3000

nested.struct.mode

How nested STRUCT fields are handled. Possible values are: CONCAT, FLATTEN, IGNORE, DISALLOW.

CONCAT (separator defined in nested.struct.concat.separator)

nested.struct.concat.separator

The separator that is used to concatenate nested field names into Ignite column name when nested.struct.mode is set to CONCAT. For example, if separator is _ and nested field is address.street, the column name will be address_street.

Underscore symbol (_)

flush.mode

Flush mode. Possible values are: KAFKA - Kafka decides when to flush, based on offset.flush.interval.ms configuration, ON_PUT - flush on every put. This causes more frequent flushes and may affect performance.

KAFKA

ignite.addresses

Required. Addresses of the GridGain nodes the data will be sent to.

ignite.authenticator.basic.password

Password for basic authentication to the GridGain cluster.

ignite.authenticator.basic.username

Username for basic authentication to the GridGain cluster.

ignite.background.reconnect.interval

Background reconnect interval in milliseconds. Set to 0 to disable background reconnect.

ignite.connect.timeout

Socket connection timeout, in milliseconds.

5000

ignite.error.handling.policy

Error handling policy. Supported values: LOG_ONLY - the entry will be skipped while writing the error to the log. STOP_TASK - the task will be stopped when the error happens. DEAD_LETTER_QUEUE - problematic records will be redirected to the configured Dead Letter Queue topic without stopping the processing.

LOG_ONLY

ignite.heartbeat.interval

An interval at which the client sends heartbeat messages to the cluster, in milliseconds. 0 disables heartbeats.

30000

ignite.heartbeat.timeout

Heartbeat response timeout, in milliseconds. The connection is closed if the response is not received before the timeout occurs.

5000

ignite.reconnect.interval

Reconnect interval, in milliseconds. 0 disables background reconnects.

30_000

ignite.ssl.client.authentication.mode

Client authentication mode: NONE, OPTIONAL, or REQUIRE.

NONE

ignite.ssl.ciphers

Comma-separated list of ciphers to be used to set up the SSL connection.

ignite.ssl.enabled

If true, an SSL/TLS connection is established.

ignite.ssl.key.store.password

Keystore password to be used to set up the SSL connection.

ignite.ssl.key.store.path

Keystore path to be used to set up the SSL connection.

ignite.ssl.trust.store.password

Truststore password to be used to set up the SSL connection.

ignite.ssl.trust.store.path

Truststore path to be used to set up the SSL connection.

ignite.streamer.auto.flush.interval

Ignite data streamer’s auto-flush interval. The interval, in milliseconds, after which the data streamer will automatically flush the data to the cluster.

5000

ignite.streamer.page.size

Ignite data streamer’s page size. The number of entries that will be sent to the cluster per network call.

1000

ignite.streamer.parallel.ops

Ignite data streamer’s parallel operations. The number of parallel operations per partition. Defines how many in-flight requests can be active per partition.

ignite.streamer.retry.limit

Ignite data streamer’s retry limit. The number of retries in case of a connection issue.

ignite.streamer.receiver.class.name

Specifies the fully qualified class name of the custom receiver to use with the streamer. The receiver must implement DataStreamerReceiver<Tuple, Tuple, Void> to ensure proper integration with the connector

ignite.streamer.receiver.deployment.units

Accepts a comma-separated list of deployment units in the format name:version. Use this property together with the ignite.streamer.receiver.class.name for the system to be able to find your receiver.

ignite.table.name.regex

The regular expression pattern that will be replaced in the topic name. See the examples below for how to use regular expressions.

ignite.table.name.regex.replacement

The value regular expression match will be replaced by.

ignite.table.name.regex.1

Optional ordering for regular expressions. Expressions with lower number will be applied first.

ignite.table.name.regex.replacement.1

Optional ordering for regular expressions. Expressions with lower number will be applied first.

Incoming Data Transformation

To apply changes to incoming data, you can use Kafka Single Message Transformations (SMTs) that allow you to modify messages as they flow through the connector. They let you convert field types, rename or remove fields, flatten nested structures, filter values, and more.

For detailed options and examples, please refer to the official SMT documentation.

For more advanced transformations beyond SMTs, see the Streamer Receiver section.

Streamer Receiver

Streamer Receiver functionality allows you to process incoming Kafka data with your own custom logic, implemented in Java, and deployed to GridGain cluster.

You can specify the deployment unit containing your receiver via ignite.streamer.receiver.deployment.units parameter along with ignite.streamer.receiver.class.name. If you decide to use a receiver, add these parameters to your connector configuration and define your deployment units and receiver name:

ignite.streamer.receiver.class.name=com.mycompany.MyReceiver
ignite.streamer.receiver.deployment.units=moduleOne:1.0,moduleTwo:2.0

If no deployment unit is specified, the receiver class may not be found on the server. The connector forwards the configuration to the streamer regardless, but to deploy a component in the cluster, it must be included in a deployment unit for the system to know where to look for the receiver class.

Keep in mind that a single receiver is used for the entire connector, which means the same receiver processes all topics defined in the connector. If you require different processing logic for different topics, you should either create separate connectors or implement topic-specific checks within your receiver’s code.

Kafka Topic Mapping

When applying regular expressions to map Kafka topics to GridGain tables, Kafka Sink applies only the first regular expression that returns matches.

In the example below, any text in Kafka topic will be replaced by MyTable:

ignite.table.name.regex=.*
ignite.table.name.regex.replacement=MyTable

You can use standard regular expression substitution syntax. The example below will replace topic with table while maintaining the number:

ignite.table.name.regex=topic-(\d*)
ignite.table.name.regex.replacement=table-$1

Multiple regular expressions can be used to handle different topic names. The example below first tries to match topic-(\d*), and if no matches are found in topic name, tries to use the customer-(\d) expression.

ignite.table.name.regex=topic-(\d*)
ignite.table.name.regex.replacement=table-$1

ignite.table.name.regex.1=customer-(\d)
ignite.table.name.regex.replacement.2=from-$1

GridGain Configuration

On the receiving GridGain cluster, you need to manually create tables and schemas that match the data from your Kafka topics. Tables are not created automatically, and failure to have the correct table available will cause an error.

Type Conversion

GridGain Kafka Sink Connector uses the schema of the GridGain table to convert Kafka topic messages. For example, when GridGain column has the INT32 type, we expect Kafka data to have the INT8, INT16, INT32, or INT64 data type.

Full list of supported conversions is provided below:

GridGain Type	Kafka Type
INT8	INT8, INT16, INT32, INT64
INT16	INT8, INT16, INT32, INT64
INT32	INT8, INT16, INT32, INT64
INT64	INT8, INT16, INT32, INT64
FLOAT	FLOAT, DOUBLE
DOUBLE	FLOAT, DOUBLE
DATE	STRING, ARRAY
TIME	STRING, ARRAY
DATETIME	STRING, ARRAY, LONG
TIMESTAMP	STRING, ARRAY, DOUBLE
UUID	STRING
BYTE_ARRAY	STRING, ARRAY, BYTES
DECIMAL	STRING, LONG, FLOAT, DOUBLE

GridGain Type

Kafka Type

INT8

INT8, INT16, INT32, INT64

INT16

INT8, INT16, INT32, INT64

INT32

INT8, INT16, INT32, INT64

INT64

INT8, INT16, INT32, INT64

FLOAT

FLOAT, DOUBLE

DOUBLE

FLOAT, DOUBLE

DATE

STRING, ARRAY

TIME

STRING, ARRAY

DATETIME

STRING, ARRAY, LONG

TIMESTAMP

STRING, ARRAY, DOUBLE

UUID

STRING

BYTE_ARRAY

STRING, ARRAY, BYTES

DECIMAL

STRING, LONG, FLOAT, DOUBLE

Those conversions have been tested for all standard serializers and deserializers:

Json
Json with schema
Avro
Protobuf

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Last updated on Jun 11, 2025