Build Client Applications for Confluent Platform¶
Clients overview¶
You can use Apache Kafka® clients to write distributed applications and microservices that read, write, and process streams of events in parallel, at scale, and in a fault-tolerant manner, even in the case of network problems or machine failures.
The Kafka client library provides functions, classes, and utilities that you can use to create Kafka producer clients and consumer clients using various programming languages. The primary way to build production-ready producers and consumers is by using a programming language and a Kafka client library.
The official Confluent supported clients are:
- Java: The official Java client library supports the producer, consumer, Streams, and Connect APIs.
- librdkafka:
The librdkafka and the following derived clients libraries only support the
admin, producer, and consumer APIs.
- C/C++
- Python
- Go
- .NET
- JavaScript
When you use the official Confluent-supported clients, you get the same enterprise-level support that you get with the rest of Confluent Platform:
- The release cycle for Confluent-provided clients follow the Confluent release cycle, as opposed to the Kafka release cycle.
- Confluent Platform maintenance fixes are provided for the 2-3 years (2 years with the Standard Support and 3 years with the Platinum Support) after the initial release of a minor version.
Additional open-source and community-developed Kafka client libraries are available for other programming languages. Some of these include Scala, Ruby, Rust, JMS, PHP, and Elixir.
The core APIs in the Kafka client library are:
- Producer API: This API provides classes and methods for creating and sending messages to Kafka topics. It allows developers to specify message payloads, keys, and metadata and to control message delivery and acknowledgment.
- Consumer API: This API provides classes and methods for consuming messages from Kafka topics. It allows developers to subscribe to one or more topics, receive messages in batches or individually, and process messages using custom logic.
- Streams API: This API provides a high-level abstraction for building real-time data processing applications that consume, transform, and produce data streams from Kafka topics.
- Connector API: This API provides a framework for building connectors that can transfer data between Kafka topics and external data systems, such as databases, message queues, and cloud storage services.
- Admin API: This API provides functions for managing Kafka topics, partitions, and configurations. It allows developers to create, delete, and update topics and retrieve metadata about Kafka clusters and brokers.
In addition to these core APIs, the Kafka client library includes various tools and utilities for configuring and monitoring Kafka clients and clusters, handling errors and exceptions and optimizing client performance and scalability.
Client guides¶
Kafka Java Client
Docs | Tutorial | API | GitHub
Java producer and consumer shipped with Apache Kafka.
Client versions and support¶
Java client support¶
The matrix shown below follows the same support timeline as mentioned in the Confluent Platform and Apache Kafka Compatibility matrix. The Kafka clients are available for download on the org.apache.kafka/kafka-clients site.
The Kafka client version matches and maps to the version of Kafka that supports it. To learn more, see the Apache Kafka Clients Maven Repository.
Confluent supports Kafka clients included with new releases of Kafka in the interval before a corresponding Confluent Platform release, and when connecting to Confluent Cloud.
For example, on May 1, 2024, Confluent would support Java clients 3.7.x even though the corresponding Confluent Platform release, 7.7.x would not be released on May 1, 2024.
If your client’s version is not listed and your testing shows it runs, running it in production is a risk. Confluent does not support clients running unsupported versions. If you decide to risk continuing with an unsupported client version, you may find information and help in the Confluent Community.
| Java clients version | Release Date | Standard End of Support | Platinum End of Support |
|---|---|---|---|
| 3.8.x | July 26, 2024 | July 26, 2026 | July 26, 2027 |
| 3.7.x | February 27, 2024 | February 27, 2026 | February 27, 2027 |
| 3.6.x | October 11, 2023 | October 11, 2025 | October 11, 2026 |
| 3.5.x | August 25, 2023 | August 25, 2025 | August 25, 2026 |
| 3.4.x | May 4, 2023 | May 4, 2025 | May 4, 2026 |
| 3.3.x | November 4, 2022 | November 4, 2024 | November 4, 2025 |
| 3.2.x | July 6, 2022 | July 6, 2024 | July 6, 2025 |
| 3.1.x | April 5, 2022 | April 5, 2024 | April 5, 2025 |
| 3.0.x | October 27, 2021 | October 27, 2023 | October 27, 2024 |
| 2.8.x | June 8, 2021 | June 8, 2023 | June 8, 2024 |
| 2.7.x | February 9, 2021 | February 9, 2023 | February 9, 2024 |
| 2.6.x | September 24, 2020 | September 24, 2022 | September 24, 2023 |
| 2.5.x | April 24, 2020 | April 24, 2022 | April 24, 2023 |
| 2.4.x | January 10, 2020 | January 10, 2022 | January 10, 2023 |
| 2.3.x | July 19, 2019 | July 19, 2021 | July 19, 2022 |
| 2.2.x | March 28, 2019 | March 28, 2021 | March 28, 2022 |
| 2.1.x | December 14, 2018 | December 14, 2020 | December 14, 2021 |
| 2.0.x | July 31, 2018 | July 31, 2020 | July 31, 2021 |
| 1.1.x | April 16, 2018 | April 16, 2020 | April 16, 2021 |
- The end of support date applies to the stated minor version, and all maintenance versions associated with that minor version. For example, support for Kafka 2.6.4 ended on September 24, 2022.
- The two year support policy is standard. End of support is extended one year for Platinum support agreements.
librdkafka and derived client support¶
librdkafka is an open source community project available at: https://github.com/confluentinc/librdkafka.
Confluent maintains its own official, signed set of binaries for librdkafka, available to you here: https://packages.confluent.io/clients/.
| Programming Language | Library Name | Documentation |
|---|---|---|
| C/C++ Client | librdkafka | Kafka C/C++ Client |
| Go Client | confluent-kafka-go | Kafka Go Client |
| .NET Client | confluent-kafka-dotnet | Kafka .NET Client |
| Python Client | confluent-kafka-python | Kafka Python Client |
| librdkafka Client Version | Release Date | Standard End of Support | Platinum End of Support |
|---|---|---|---|
| 2.6.x | October 12, 2024 | October 12, 2026 | October 12, 2027 |
| 2.5.x | July 10, 2024 | July 10, 2026 | July 10, 2027 |
| 2.4.x | May 7, 2024 | May 7, 2026 | May 7, 2027 |
| 2.3.x | October 26, 2023 | October 26, 2025 | October 26, 2026 |
| 2.2.x | July 13, 2023 | July 13, 2025 | July 13, 2026 |
| 2.1.x | April 6, 2023 | April 6, 2025 | April 6, 2026 |
| 2.0.x | January 24, 2023 | January 24, 2025 | January 24, 2026 |
| 1.9.x | June 16, 2022 | June 16, 2024 | June 16, 2025 |
| 1.8.x | September 22, 2021 | September 22, 2023 | September 22, 2024 |
| 1.7.x | August 8, 2021 | August 8, 2023 | August 8, 2024 |
| 1.6.x | February 21, 2021 | February 21, 2023 | February 21, 2024 |
- An end-of-support date is based on the first release of the specified minor version. The support date windows apply to that minor version and any maintenance/patch versions that come under the minor version. For example, 1.9.0 and 1.9.1 would have the same support windows as specified for 1.9.x.
- The two-year support policy is standard. End of support is extended one year for Platinum support agreements.
Client examples¶
To learn how to build Kafka clients apps using your favorite language, including Java, .NET, Python, JavaScript, C/C++, and Go, see Kafka Client Examples for Confluent Platform.
Note
Confluent recommends upgrading to the latest client since current fixes are generally not found in older clients.
Supported Confluent Platform Features for Kafka Clients¶
The following tables describes the client support for various Confluent Platform features.
| Feature | C/C++ | Go | Java | .NET | Python |
|---|---|---|---|---|---|
| Admin API | Yes | Yes | Yes | Yes | Yes |
| Control Center metrics integration | Yes | Yes | Yes | Yes | Yes |
| Custom partitioner | Yes | No | Yes | No | No |
| Exactly Once Semantics | Yes | Yes | Yes | Yes | Yes |
| Idempotent Producer | Yes | Yes | Yes | Yes | Yes |
| Kafka Streams | No | No | Yes | No | No |
| Record Headers | Yes | Yes | Yes | Yes | Yes |
| SASL Kerberos/GSSAPI | Yes | Yes | Yes | Yes | Yes |
| SASL PLAIN | Yes | Yes | Yes | Yes | Yes |
| SASL SCRAM | Yes | Yes | Yes | Yes | Yes |
| SASL OAUTHBEARER | Yes | Yes | Yes | No | No |
| Simplified installation | Yes | Yes | Yes | Yes | Yes |
| Schema Registry | Yes | No | Yes | Yes | Yes |
| Topic Metadata API | Yes | Yes | Yes | Yes | Yes |