VMware Tanzu GemFire Sink Connector for Confluent Platform¶

The Kafka Connect VMware Tanzu™ GemFire Sink connector exports data from Apache Kafka® to VMware Tanzu GemFire. The VMware Tanzu GemFire Sink connector periodically polls data from Kafka and adds it to VMware Tanzu GemFire.

Note

This connector is compatible with VMware Tanzu GemFire 9.x and above.

Features¶

The Tanzu GemFire Sink connector includes the following features:

At least once delivery
Dead Letter Queue
Multiple tasks

At least once delivery¶

This connector guarantees that records from the Kafka topic are delivered at least once.

Dead Letter Queue¶

This connector supports the Dead Letter Queue (DLQ) functionality. For information about accessing and using the DLQ, see Confluent Platform Dead Letter Queue.

Multiple tasks¶

The Tanzu GemFire Sink connector supports running one or more tasks. You can specify the number of tasks in the tasks.max configuration parameter. This can lead to performance gains when multiple files need to be parsed.

Limitations¶

The connector supports only one task since it can create only one region object (client to write data). More information can be found here.
This connector expects non-null keys, hence having explicit keys and values is necessary for the data to be exported to Tanzu GemFire.

License¶

You can use this connector for a 30-day trial period without a license key.

After 30 days, you must purchase a connector subscription which includes Confluent enterprise license keys to subscribers, along with enterprise-level support for Confluent Platform and your connectors. If you are a subscriber, you can contact Confluent Support at support@confluent.io for more information.

See Confluent Platform license for license properties and License topic configuration for information about the license topic.

Configuration Properties¶

For a complete list of configuration properties for this connector, see Configuration Reference for VMware Tanzu GemFire Sink Connector for Confluent Platform.

For an example of how to get Kafka Connect connected to Confluent Cloud, see Connect Self-Managed Kafka Connect to Confluent Cloud.

Install the VMware Tanzu GemFire Connector¶

You can install this connector by using the confluent connect plugin install command, or by manually downloading the ZIP file.

Prerequisites¶

You must install the connector on every machine where Connect will run.
Kafka Broker: Confluent Platform 3.3.0 or later, or Kafka 0.11.0 or later.
Connect: Confluent Platform 4.0.0 or later, or Kafka 1.0.0 or later.
An installation of the latest (latest) connector version.

To install the latest connector version, navigate to your Confluent Platform installation directory and run the following command:
```
confluent connect plugin install confluentinc/kafka-connect-cassandra:latest
```
You can install a specific version by replacing latest with a version number as shown in the following example:
```
confluent connect plugin install confluentinc/kafka-connect-cassandra:1.0.10
```

Install the connector manually¶

Download and extract the ZIP file for your connector and then follow the manual connector installation instructions.

Quick Start¶

In this quick start, the VMware Tanzu GemFire Sink connector is used to export data produced by the Avro console producer to the Tanzu GemFire cache region.

Note

Before you begin: Start the VMware Tanzu GemFire locator and server. Create a cache region to store the data.

Start the services using the Confluent CLI.

confluent local services start

Every service starts in order, printing a message with its status.

Starting Zookeeper
Zookeeper is [UP]
Starting Kafka
Kafka is [UP]
Starting Schema Registry
Schema Registry is [UP]
Starting Kafka REST
Kafka REST is [UP]
Starting Connect
Connect is [UP]
Starting KSQL Server
KSQL Server is [UP]
Starting Control Center
Control Center is [UP]

To import a few records with a simple schema in Kafka, start the Avro console producer as follows:

  ./bin/kafka-avro-console-producer --broker-list localhost:9092 --topic input_topic \
--property value.schema='{"type":"record","name":"myrecord","fields":[{"name":"f1","type":"string"}]}'

Then, in the console producer, enter the following:

{"f1": "value1"}
{"f1": "value2"}
{"f1": "value3"}

The three records entered are published to the Kafka topic input_topic in Avro format.

Property-based example¶

Create a configuration file, gemfire.properties. This configuration is used typically along with standalone workers.

name=gemfire-sink
connector.class=io.confluent.connect.pivotal.gemfire.PivotalGemfireSinkConnector
tasks.max=1
topics=input_topic
gemfire.locator.host=localhost
gemfire.locator.port=10334
gemfire.username= <gemfire username>
gemfire.password= <gemfire password>
gemfire.region=check
confluent.topic.bootstrap.servers=localhost:9092
confluent.topic.replication.factor=1

Before starting the connector, make sure that the configurations in gemfire.properties are properly set.

Note

Provide either gemfire.locator.host or gemfire.server.host to establish connection with VMware Tanzu GemFire and run the connector

Then start the VMware Tanzu GemFire connector by loading its configuration with the following command:

Caution

You must include a double dash (--) between the connector name and your flag. For more information, see this post.

confluent local services connect connector load gemfire-sink --config gemfire.properties
{
 "name": "gemfire-sink",
 "config": {
     "name":"gemfire-sink",
     "connector.class":"io.confluent.connect.pivotal.gemfire.PivotalGemfireSinkConnector",
     "tasks.max":"1",
     "topics":"input_topic",
     "gemfire.locator.host":"localhost",
     "gemfire.locator.port":"10334",
     "gemfire.username":"<gemfire username>",
     "gemfire.password":"<gemfire password>",
     "gemfire.region":"check",
     "confluent.topic.bootstrap.servers":"localhost:9092",
     "confluent.topic.replication.factor":"1"
 },
  "tasks": []
}

REST-based example¶

Use this setting with distributed workers. Write the following JSON to config.json, configure all of the required values, and use the following command to post the configuration to one of the distributed connect workers. Check here for more information about the Kafka Connect REST API

 {
 "name": "gemfire-sink",
 "config": {
     "name":"gemfire-sink",
     "connector.class":"io.confluent.connect.pivotal.gemfire.PivotalGemfireSinkConnector",
     "tasks.max":"1",
     "topics":"input_topic",
     "gemfire.locator.host":"localhost",
     "gemfire.locator.port":"10334",
     "gemfire.username":"<gemfire username>",
     "gemfire.password":"<gemfire password>",
     "gemfire.region":"check",
     "confluent.topic.bootstrap.servers":"localhost:9092",
     "confluent.topic.replication.factor":"1"
 }
}

Use curl to post the configuration to one of the Kafka Connect Workers. Change http://localhost:8083/ the endpoint of one of your Kafka Connect worker(s).

curl -s -X POST -H 'Content-Type: application/json' --data @config.json http://localhost:8083/connectors

Use the following command to update the configuration of existing connector.

curl -s -X PUT -H 'Content-Type: application/json' --data @config.json http://localhost:8083/connectors/ServiceBusSourceConnector/config

Check that the connector started successfully. Review the Connect worker’s log by entering the following:

confluent local services connect log

Towards the end of the log you should see that the connector starts, logs a few messages, and then adds data from Kafka to the Tanzu GemFire check cache region.

Once the connector has ingested records, check that the data is available in the Tanzu GemFire check cache region. Use the following command:

To see the values in the Gemfire check region.

query --query="select * from /check"
Result : true
Limit  : 100
Rows   : 3
Result
-----------
{"f1": "value1"}
{"f1": "value2"}
{"f1": "value3"}

To see the keys in the Gemfire check region.

query --query="select * from /check.keySet"
Result : true
Limit  : 100
Rows   : 3
Result
-----------
kafka1$0$1
kafka1$0$2
kafka1$0$3

Finally, stop the Connect worker and all other Confluent services by running:

confluent local stop

Your output should resemble:

Stopping Control Center
Control Center is [DOWN]
Stopping KSQL Server
KSQL Server is [DOWN]
Stopping Connect
Connect is [DOWN]
Stopping Kafka REST
Kafka REST is [DOWN]
Stopping Schema Registry
Schema Registry is [DOWN]
Stopping Kafka
Kafka is [DOWN]
Stopping Zookeeper
Zookeeper is [DOWN]

You can stop all services and remove any data generated during this quick start by entering the following command:

confluent local destroy

Your output should resemble:

Stopping Control Center
Control Center is [DOWN]
Stopping KSQL Server
KSQL Server is [DOWN]
Stopping Connect
Connect is [DOWN]
Stopping Kafka REST
Kafka REST is [DOWN]
Stopping Schema Registry
Schema Registry is [DOWN]
Stopping Kafka
Kafka is [DOWN]
Stopping Zookeeper
Zookeeper is [DOWN]
Deleting: /var/folders/ty/rqbqmjv54rg_v10ykmrgd1_80000gp/T/confluent.PkQpsKfE