Codern is an open-source coding platform that focuses on providing a seamless setup for coding event organizers and participants, enabling them to enhance their programming skills through interactive coding experiences.

We utilize third-party software, developed by Porama6400, for grading the source code submitted by users on our platform.

%%{init: {'theme': 'neutral' } }%%
graph LR
 nginxIngress --> k8s
 client["Client"]
 client -->|http/https/websocket| nginxIngress
 k8s -.-|monitor| observer
 datastore -.-|monitor| observer
 messageBroker -.-|monitor| observer
 vm2 -.-|monitor| observer
 backend <-->|pub/consume| rabbitmq
 backend -->|query| mysql
 backend -->|query| influxdb
 backend -->|proxy| seaweedfs
 gradingCore <-->|pub/consume| rabbitmq
 subgraph codern["Codern cluster (Cold state)"]
 nginxIngress["Nginx ingress"]
 subgraph vm1["Virtual machine"]
 subgraph k8s["Kubernetes environment"]
 backend["Backend Pod"]
 frontend["Frontend Pod"]
 end
 subgraph docker["Docker environment"]
 subgraph datastore["Datastore containers"]
 direction TB
 mysql["MySQL"]
 influxdb["InfluxDB"]
 seaweedfs["SeaweedFS"]
 end
 subgraph messageBroker["Message broker"]
 rabbitmq["RabbitMQ"]
 end
 subgraph observer["Observability containers"]
 direction TB
 grafana["Grafana"]
 prometheus["Prometheus"]
 end
 end
 end
 subgraph vm2["Virtual machine"]
 dockerd
 gradingCore -->|manage container| dockerd
 subgraph docker2["Docker environment"]
 gradingCore["Grading Core"]
 end
 end
 end
style vm1 fill:#ced4da
style vm2 fill:#ced4da
style datastore fill:#e9ecef
style messageBroker fill:#e9ecef
style observer fill:#e9ecef

Behind the scenes, the Codern API server was built using lighting-fast web framework, Fiber. Our codebase was designed with a monolithic architecture. Previosuly, we adopted a Microservice architecture for building everything (see legacy version), but we eventually made the decision to switch back to a monolith. We found that the Microservice architecture didn't provide us any significant advantages, only introducing development difficulties. As the result, we opted for the more streamlined monolithic approach.

This project follows the Clean Architecture principles, ensuring a modular and maintainable codebase. With clear separation of core business logic from external dependencies, it promotes flixibility and scalability. This approach also facilitates easier testing.

Thanks to Uncle Bob, for the article of Clean Architecture.

This project utilizes InfluxDB, Prometheus, Grafana and to achieve a robust log and metric management system. With InfluxDB for time-series storage, Prometheus for monitoring, and Grafana for visualization, we ensure optimal performance and proactive issue detection.

We are currently in the beta version of the development phase, and we had the opportunity to run and exeperiment with our system design during the Bangmod Hacakthon 2024. This event, organized by King Mongkut University of Technology Thonburi, saw participation from approximately 200 schools across Thailand in this coding competition.

During the 3-hour event, we encountered a high traffic load on our system, with around 400,000 requests (40 req/s). It's important to note that we were using only one instance of the main server (4 CPU cores / 8 GB RAM) and two instances of worker servers (1 CPU core / 1 GB RAM). Users had a positive experience, receiving code results quickly from our system, with an average grading latency of about 7 seconds.

We are proud to share that our system demonstrated an impressive success rate of 99.99% on API requests during the Bangmod Hackathon 2024, showcasing the robustness and reliability of our platform even under high traffic conditions.

There are many ways in which you can participate in this project, for example:

• Submit bugs and feature requests.
• Fixing issues and contributing directly to the code base by submitting pull requests.

Copyright (c) Vectier. All rights reserved.