eike.schumann/kafka-cqrs

This system is a document management platform built on a CQRS (Command Query Responsibility Segregation) architecture, separating write and read operations. It exposes a REST API to create, update, and delete documents, which are then persisted to a Cassandra database via a background service. The system also provides real-time notifications via Server-Sent Events and a React-based web interface for user interaction.

A new application.properties file has been added to the producer-service resources, establishing default settings for the server port (8083) and Kafka connectivity (bootstrap servers and topic).

producer-service/src/main/resources · high confidence

The persister-service is now containerized with a new Dockerfile and entrypoint script. The container uses OpenJDK 13 Alpine, installs bash and netcat, and runs the application via a shell script that waits for the Cassandra service to become available on port 9042 before starting.

persister-service · high confidence

The Terraform module now fully provisions an AWS environment for running Apache Kafka and Zookeeper. It defines an EC2 instance (Ubuntu 16.04 LTS) with a security group allowing SSH and Kafka port 9092 access, along with an Elastic IP. The configuration includes scripts to download and install Java, Zookeeper, and Kafka, and sets up systemd services for both. Outputs are provided for SSH and Telnet connectivity.

terraform · high confidence

The web-ui area introduces a new React-based interface for creating, reading, updating, and deleting documents, alongside a real-time notifications panel. The UI renders four main action forms (Create, Read, Update, Delete) and a notifications section, each wired to make HTTP requests via Axios and display the request and response payloads. The NotificationsContainer establishes an EventSource connection to receive server-sent events, while the build configuration (Webpack, Babel, SCSS) supports the new frontend code.

web-ui · high confidence

The producer-service now exposes a REST API for creating, updating, and deleting documents. Each operation sends a corresponding message (Create, Update, or Delete) to a Kafka topic via a new Kafka configuration and SenderService. The create endpoint returns the generated document ID in the response, while update and delete endpoints return standard HTTP status codes. This adds the producer-side implementation for the CQRS pattern, handling request assembly and message serialization.

producer-service/src/main/java · high confidence

Added a new persister-service that listens to Kafka topics and persists incoming messages to a Cassandra database. The service includes configuration for Kafka consumers, a message model, and a repository layer that handles upsert and delete operations against Cassandra, enabling the system to store and manage document data based on Kafka events.

persister-service/src/main/java · high confidence

Adds a new reader service that exposes a REST endpoint to retrieve documents by ID from a Cassandra database. The service is packaged as a Docker image using OpenJDK 13 and includes a startup script that waits for the Cassandra service to become available before launching the application. The implementation includes a Spring Boot application, a Cassandra configuration, a document model, a REST controller, and a UUID converter, along with corresponding integration and unit tests.

reader-service · high confidence

Added the Notifier Service, a new component that listens for messages from a Kafka topic and exposes them via a server on port 8081 using Server-Sent Events. The service is configured with Kafka connection details and a consumer group, and integrates with the existing Kafka infrastructure.

notifier-service/src/main · high confidence

The test-utils module now includes a suite of new helper classes to support integration testing. HTTP testing is supported via new clients (NotifierClient, ProducerClient, ReaderClient) and response wrappers (JsonResponse, SseResponse, SseEvent) that use the Java 11 HttpClient. Kafka testing is enabled through a @KafkaTopic annotation and a Spring ContextCustomizer that automatically injects configured KafkaTemplate instances into test fields. Additional utilities include a Vert.x test helper (TestVertx) for deploying verticles in tests, a TCP utility to find free ports, and shared utilities for loading Java properties and serializing JSON.

test-utils/src/main/java · high confidence

A new Spring Boot auto-configuration file (META-INF/spring.factories) has been added to the test-utils module. This registers a custom Spring Test ContextCustomizerFactory (pl.jojczykp.kafka\_cqrs.test\_utils.kafka.KafkaTopicContextCustomizerFactory), enabling automatic setup of Kafka topics for tests without manual configuration.

test-utils/src/main/resources · high confidence

A new application.properties file was added to the persister-service resources, defining connection details for Kafka (bootstrap servers, group, and topic) and Cassandra (node, port, keyspace, and table). This enables the service to connect to these external systems.

persister-service/src/main/resources · high confidence

Added end-to-end tests for document lifecycle; Added test configuration for Kafka CQRS logging; Added test resources for Cassandra and logging configuration; Added tests for DocumentRepository; Added tests for Kafka and Web notifier verticles; Added unit and integration tests for the producer service; Added unit tests for Kafka listener and persistence services.

The repository has been restructured into a multi-module Gradle project named 'kafka-cqrs', replacing the previous 'aws-kafka' root. This change introduces several new subprojects: 'producer-service', 'notifier-service', 'persister-service', 'reader-service', 'test-utils', and 'e2e-tests'. The build is configured to use Java 11, Spring Boot 2.1.1, Spring Kafka 2.2.2, and various other libraries like Lombok, Guava, and Spock. A new 'web-ui' module is also added with React and Webpack dependencies. The Gradle wrapper is updated to version 5.1, and Docker build tasks are integrated for the service modules.

(dependencies) · medium confidence

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

• CAI 35 → 36 (+1.1)
• Rubric changed (rubric-2026.08.19 → rubric-2026.09.15) — scores are not directly comparable.

• Code Health 54 → 57 (+2.3)
• Architecture 69 → 84 (+14.7)
• Maturity 47 → 47 (+0.0)
• Readiness 17 → 17 (+0.0)
• Security 81 → 80 (-1.0)
• Accessibility 45 → 46 (+1.7)

• Coverage not included — suite not readable by the collector
• Dependency hygiene not measured — dependency manifest found but not parsed for hygiene
• Medium IaC: CKV_AWS_126 (terraform/kafka.tf)
• Medium IaC: CKV_AWS_23 (terraform/kafka.tf)
• Medium IaC: CKV_DOCKER_3 (notifier-service/Dockerfile)
• Medium IaC: CKV_DOCKER_3 (persister-service/Dockerfile)
• Medium IaC: CKV_DOCKER_3 (producer-service/Dockerfile)
• Medium IaC: CKV_DOCKER_3 (reader-service/Dockerfile)
• Medium IaC: CKV_DOCKER_6 (notifier-service/Dockerfile)
• Medium IaC: CKV_DOCKER_6 (persister-service/Dockerfile)
• Medium IaC: CKV_DOCKER_6 (producer-service/Dockerfile)
• Medium IaC: CKV_DOCKER_6 (reader-service/Dockerfile)
• Medium: security finding (details withheld)
• No exposed public API
• Scanner failed to run — not a clean result
• Test reliability not included
• single-maintainer — knowledge-concentration (bus factor) risk

• Change coupling clique: CreateDocumentContainer.jsx, DeleteDocumentContainer.jsx, ReadDocumentContainer.jsx, UpdateDocumentContainer.jsx (web-ui/src/js/components/container/CreateDocumentContainer.jsx)
• Critical IaC: AWS-0104 (terraform/kafka.tf)
• Dependency hygiene PARTLY measured — Maven/Gradle declarations read, no dependency graph resolved
• Documentation: no installation or build instructions (README.md)
• Documentation: no usage examples (README.md)
• Duplicated block (10 lines × 2) (notifier-service/src/main/java/pl/jojczykp/kafka_cqrs/notifier/config/KafkaConfig.java)
• High: security finding (details withheld)
• Low IaC: AWS-0124 (terraform/kafka.tf)
• Low IaC: AWS-0124 (terraform/kafka.tf)
• Low IaC: AWS-0124 (terraform/kafka.tf)
• Medium IaC: WD-DOCKER-0003 (notifier-service/Dockerfile)
• Medium IaC: WD-DOCKER-0003 (persister-service/Dockerfile)
• Medium IaC: WD-DOCKER-0003 (producer-service/Dockerfile)
• Medium IaC: WD-DOCKER-0003 (reader-service/Dockerfile)
• No ADRs found
• Scanner failed to run — not a clean result
• Scanner failed to run — not a clean result

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

eike.schumann/kafka-cqrs was measured the same way every project in this corpus was: the same rubric, at a pinned commit, with the result published in full. Point a surveyor at a repository you know and see whether you agree with it.