Building Resilient and Scalable Systems w/ Google Cloud Pub/Sub

Written By happtiq hosting

Consider an individual attempting to play all the instruments in a musical ensemble simultaneously. While this image is amusing, it illustrates a significant issue in software architecture: systems that lack scalability. Similar to how a solo musician cannot easily incorporate new instruments, take a break, or perform complex compositions, tightly coupled software systems encounter challenges in adapting and expanding.

This is where Google Cloud Pub/Sub comes in. It enables building resilient and scalable systems by decoupling services and facilitating asynchronous communication. In this blog post, we'll explore the challenges of traditional architectures and how Pub/Sub provides a suitable solution.

The Challenges of Traditional Architectures

Traditional monolithic or client-server architectures often struggle with scalability, flexibility, and maintainability. These architectures, where components are tightly coupled, can introduce bottlenecks as user demand grows. Their centralized nature creates single points of failure, increasing the risk of outages. Moreover, modifying a monolithic system often requires redeploying the entire application, making updates complex and time-consuming.

While microservices improve scalability by distributing workloads, they introduce new challenges, such as increased network latency, inter-service communication overhead, and data consistency issues in highly concurrent environments. As the number of services grows, improper load balancing or inefficient service orchestration can lead to performance degradation. Ensuring synchronization across multiple distributed components remains a key challenge, particularly in high-frequency update scenarios.

Event-Driven Architecture as a Solution

Event-driven architecture (EDA) offers an alternative approach. In an EDA, microservices communicate through events, such as "order dispatched" or "product price changed." This decoupling enabled by a messaging platform like Google Cloud Pub/Sub allows services to operate independently and respond to events as they occur.

Key advantages of EDA include:

  • Loose Coupling: Services are independent and can be updated or scaled without affecting others.

  • Improved Agility: New services can be added easily, and existing ones can be modified or replaced.

  • Asynchronous Eventing: Events are processed asynchronously, improving performance and responsiveness.

  • Resiliency: If one service fails, the others continue to operate.

Google Cloud Pub/Sub: The Power of Decoupling

Google Cloud Pub/Sub is a scalable, flexible, and reliable messaging service that facilitates communication between different applications and services using asynchronous messaging. It adheres to the principles of event-driven architecture, which promotes loose coupling between software components. This decoupling is achieved by separating services that generate messages (publishers) from those that consume them (subscribers). Publishers send messages to Pub/Sub topics without knowledge of which subscribers will receive them. Conversely, subscribers express interest in specific topics and receive messages from those topics without knowledge of which publishers sent them.

Key features of Google Cloud Pub/Sub include:

  • Topics and Subscriptions: Publishers send messages to topics, and subscribers create subscriptions to topics to receive messages.

  • Push and Pull Delivery: Subscribers can either pull messages from Pub/Sub or have Pub/Sub push messages to them depending on your architecture.

  • Filtering: Subscribers can filter messages based on attributes to receive only the messages they are interested in.

  • Replay: Messages can be replayed to subscribers for a configured period of time.

  • Dead-Letter Topics: Undeliverable messages can be sent to a dead-letter topic for further analysis.

  • Exactly-Once Delivery: Pub/Sub can guarantee that messages will be delivered to subscribers exactly once in addition to traditional at least once delivery.

Overall, Google Cloud Pub/Sub is a powerful tool for building event-driven architectures and enabling communication between loosely coupled services. Its scalability, flexibility, and reliability make it a popular choice for a wide range of applications.

Real-World Use Cases

Pub/Sub is used in a variety of applications, including:

  • Data Streaming: Ingesting user interaction and server events for analysis.

  • Real-Time Systems: Distributing events for real-time processing.

  • Cross-Service Communication: Enabling communication between microservices in large-scale applications.

For example, a customer behavior data platform could use Pub/Sub to collect and process user interaction events in real-time, enabling personalized experiences and business insights.

Case Study: Customer Behavior Data Platform

The case study revolves around building a customer behavior data platform. The challenge was to handle a massive influx of data: billions of events, millions of users, and terabytes of data. To address this, we created "Avalanche," a customer behavior data platform leveraging Google Cloud Pub/Sub.

Challenges:

  • Scale: Handling billions of events, millions of users, and terabytes of data.

  • Real-time Processing: The need for real-time data ingestion and processing.

  • GDPR Compliance: Ensuring data privacy and compliance with GDPR regulations.

  • Cost Efficiency: Keeping costs low while managing a large-scale platform.

  • Data Quality: Maintaining high-quality customer data.

Implementation Details

The following components are used:

  • Data Ingestion: To ingest user interaction events (e.g., page visits)

  • Stream Processing: To Enrich and process the events in real-time.

  • Google Cloud Pub/Sub: To enable event-driven communication and event streaming between the different components

  • Data Warehousing: Processed data is delivered to  GCP BigQuery for further enrichment and distribute to the dashboards  

Key Results:

Following the implementation of "Avalanche," our behavioral data platform, for our client, we observed notable advancements in data processing efficiencies and business results. Specifically, the following significant outcomes were documented in December 2024:

  • 100k Monthly Users: The platform handles data for a significant user base.

  • 8 Million Monthly Events: 500 events per minute at peak time

  • 56 GB of Ingested Data: the platform scales to gigabytes of data and can handle more

  • <150ms Latency: Realtime platform from data ingestion till the warehouse 

  • ~5 Euros Pub/Sub Costs: Pub/Sub usage costs were relatively low.

Takeaways:

  • Customer Understanding: The importance of deeply understanding your customers.

  • Architecture and Design: Choosing the correct architecture and design patterns.

  • Tool Knowledge: Proficiency in using the chosen tools (Google Cloud Pub/Sub and related services).

Avalanche is a real-world example of how Google Cloud Pub/Sub can be used to build a scalable, real-time data processing system. It highlights the benefits of Pub/Sub in handling large volumes of data, ensuring low latency, and maintaining cost efficiency.

Summary

Google Cloud Pub/Sub offers a robust solution for overcoming the limitations of traditional architectures, enabling the development of resilient, scalable, and event-driven systems. By decoupling services and supporting asynchronous communication, Pub/Sub facilitates real-time data streaming, efficient cross-service communication, and compliance with data regulations. Its versatility and scalability make it a valuable tool for modern cloud-based applications.

Want to learn more about what we offer? Check out our website at https://www.happtiq.com/avalanche 

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