Stream and Analyze PostgreSQL Data from S3 Using Kafka and ksqlDB: Part 2

Introduction

In Part 1, we set up a real-time data pipeline that streams PostgreSQL changes to Amazon S3 using Kafka Connect. Here’s what we accomplished:

  • Configured PostgreSQL for CDC (using logical decoding/WAL)
  • Deployed Kafka Connect with JDBC Source Connector (to capture PostgreSQL changes)
  • Set up an S3 Sink Connector (to persist data in S3 in Avro/Parquet format)

In Part 2 of our journey, we dive deeper into the process of streaming data from PostgreSQL to S3 via Kafka. This time, we explore how to set up connectors, create a sample PostgreSQL table with large datasets, and leverage ksqlDB for real-time data analysis. Additionally, we’ll cover the steps to configure AWS IAM policies for secure S3 access. Whether you’re building a data pipeline or experimenting with Kafka integrations, this guide will help you navigate the essentials with ease.

Visual Data Flow Diagram

Role of Each Component

Component Responsibility Key Tools Used
PostgreSQL Source database emitting Change Data Capture (CDC) events via WAL wal2jsonDECODING
Kafka (Brokers) Ingests and buffers real-time data changes from PostgreSQL JDBC Source ConnectorTopics
Kafka Connect Bridges PostgreSQL → Kafka → S3 with fault-tolerant pipelines S3 Sink ConnectorAvro/Parquet
Amazon S3 Stores raw CDC logs for historical analysis (data lake) Parquet formatPartitioning
ksqlDB Processes streams in real-time (filtering, joins, aggregations) CREATE STREAMPUSH QUERIES
Downstream Apps Consume processed data (dashboards, alerts, APIs) Kafka ConsumersREST Endpoints

Step-by-Step Implementation

Let’s pick up where we left off in Part 1 and continue building our data pipeline by setting up connectors, creating sample data, and configuring S3 for seamless integration.

Step 1

Enter

Output

Step 2

docker exec –tty –interactive postgres bash -c ‘psql -U $POSTGRES_USER $POSTGRES_DB’

Step 3

Enter

Output

Step 4

docker exec -it ksqldb ksql http://ksqldb:8088
show connectors;

Step 5

kafkacat -b localhost:9092 -t postgres-employees -C -o beginning -f ‘%o %s\n’

Step-6

on aws
create a user through iam console
and add a policy into the same
by making a new policy

here you can manage the policy by specifying the s3 service required into your policy and bucket to which you want to apply this policy

Final Step

 

Blog PunditSandeep Rawat Opstree is an End to End DevOps solution provider

Author: Shristi Gupta

Devops, Devops Solutioning, Linux, Terraform, AWS

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