Can we use Kafka with Nodejs?

Kafka is an open-source event streaming platform, used for publishing and processing events at high-throughput. There are a lot of popular libraries for Node. js in order to interface with Kafka. For this post, we will be using the kafkajs library (but the same concepts will apply for any other library as well).

What is the design rationale of Kafka not allowing multiple consumers to simultaneously consume a given partition?

In Kafka, only one consumer instance can consume messages from a partition. If consumer instances are more than partitions, then there will be no use of extra consumer instances. So kafka don’t allow these extra consumer instances.

How does the Kafka console consumer connect to Kafka cluster?

Step 1: Start the zookeeper as well as the kafka server initially. Step2: Type the command: ‘kafka-console-consumer’ on the command line. This will help the user to read the data from the Kafka topic and output it to the standard outputs.

Which strategy will help client to guarantee exactly once data processing?

Building on idempotency and atomicity, exactly-once stream processing is now possible through the Streams API in Apache Kafka. All you need to make your Streams application employ exactly-once semantics, is to set this config processing. guarantee=exactly_once .

What is Kafka cluster?

A Kafka cluster consists of one or more servers (Kafka brokers) running Kafka. Producers are processes that push records into Kafka topics within the broker. A consumer pulls records off a Kafka topic. Management of the brokers in the cluster is performed by Zookeeper.

How does Kafka handle multiple consumers?

While Kafka allows only one consumer per topic partition, there may be multiple consumer groups reading from the same partition. Multiple consumers may subscribe to a Topic under a common Consumer Group ID, although in this case, Kafka switches from sub/pub mode to a queue messaging approach.

How do you use multiple consumers in Kafka?

You can’t have multiple consumers that belong to the same group in one thread and you can’t have multiple threads safely use the same consumer. One consumer per thread is the rule. To run multiple consumers in the same group in one application, you will need to run each in its own thread.

How do I connect to Kafka cluster?

To connect to the Kafka cluster from the same network where is running, use a Kafka client and access the port 9092. You can find an example using the builtin Kafka client on the Kafka producer and consumer page.

How do I use Kafka consumer console?

Run it

1. Initialize the project. To get started, make a new directory anywhere you’d like for this project:
2. Get Confluent Platform.
3. Create the Kafka topic.
4. Start a console consumer.
5. Produce your first records.
6. Read all records.
7. Start a new consumer to read all records.
8. Produce records with full key-value pairs.

How does Kafka guarantee at least once?

At least once guarantee means you will definitely receive and process every message, but you may process some messages additional times in the face of a failure. An application sends a batch of messages to Kafka. The application never receives a response so sends the batch again.

How does Kafka guarantee exactly-once?

A batch of data is consumed by a Kafka consumer from one cluster (called “source”) then immediately produced to another cluster (called “target”) by Kafka producer. To ensure “Exactly-once” delivery, the producer creates a new transaction through a “coordinator” each time it receives a batch of data from the consumer.

Should you choose Node JS or Kafka Streams for your application?

While certain situations require the rich state querying capabilities of the Java-based Kafka Streams, other scenarios, such as edge deployments or serverless functions, may prefer a more lightweight approach. Node.js, for example, generally offers faster startup times and a smaller footprint.

Is Kafka a distributed messaging system?

Just to revise, Kafka is a distributed, partitioned and replicated pub-sub messaging system. Kafka stores messages in topics (partitioned and replicated across multiple brokers). Producers send messages to topics from which consumers or their consumer groups read.

What is a Kafka cluster?

Kafka is run as a cluster on one or more servers that can span multiple datacenters. The Kafka cluster stores streams of records in categories called topics. Each record consists of a key, a value, and a timestamp.

What is connector API in Kafka?

The Connector API allows building and running reusable producers or consumers that connect Kafka topics to existing applications or data systems. For example, a connector to a relational database might capture every change to a table. In this example we use Producer and consumer API’s.