KAFKA 🚀

KAFKA - Implementation with Node.js & Kafkajs - Order Management System / Inventory management System

Case Study

In a scenario where an order management system (oms) needs to publish stock or inventory of SKUs based on company ID and channel ID.

Prerequisites

• Node.js: Download Node.js (Preferably Node.js 18.0 or the latest LTS version)
• Docker: Download Docker
• VSCode: Download VSCode
• KafkaJs: Install Kafka.js

Commands

What is ZooKeeper?

ZooKeeper is a high-performance coordination service for distributed applications. It provides common services such as naming, configuration management, synchronization, and group services.

• Start ZooKeeper Container and expose default PORT 2181:

  docker run -p 2181:2181 zookeeper

• Start Kafka Container, expose default PORT 9092, and set up ENV variables:

  docker run -p 9092:9092 \
  -e KAFKA_ZOOKEEPER_CONNECT=<PRIVATE_IP>:2181 \
  -e KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://<PRIVATE_IP>:9092 \
  -e KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1 \
  confluentinc/cp-kafka

File Structure

First Run Publisher

Running the Producer Script

1. Navigate to Your Project Directory:

   cd your_project_directory

   Or You can pull from DockerHub

   docker pull apige/kafka-node-inventory-update-for-oms-by-companyid-channelid:latest

2. Execute the Producer Script to publish your inventory by sku level:

   node producer.js

3. Provide Input When Prompted: The script will prompt you to enter the following details:

   • company_id
   • channel_id
   • sku_code
   • no_of_inventory

   Enter the values in the following format:

   5432 365667 345 8

   • company_id: 5432
   • channel_id: 365667
   • sku_code: 345
   • no_of_inventory: 8

Then Run Consumer

Running the Consumer Script to consume the inventory updates by sku level

1. Execute the Consumer Script with User Name:

   node consumer.js user-1

2. Output Example: When you run the consumer script with a specific user name (user-1 in this case), you will receive output similar to the following:

   

   • user-1 is the group name: Indicates the group name being used by the consumer script.
   • Consumer connected: Confirmation that the consumer is connected.
   • Log messages from the Kafka consumer library (Kafkajs) indicating the start of consumption and group membership details.
   • user-1: [inv-updates]: PART:0: {"company":"5432","channelId":"365667","skuCode":"345","inv":"8"}: Represents the consumed message, indicating the user, topic, partition, and message content.