What Is the Platform Event Trap and How Can You Avoid It?

As software systems grow, they need better ways to communicate. One popular method is using platform events, which let different parts of a system share information in real time. This is great for building modern, responsive applications. However, developers can sometimes fall into what’s known as the platform event trap. This happens when these events are overused or managed poorly, leading to complex, slow, and hard-to-maintain systems.

Understanding this common pitfall is the first step to avoiding it. This guide will walk you through what the platform event trap is, why it happens, and how you can design your systems to be efficient and scalable. We’ll explore the common signs that you might be heading for trouble and provide practical strategies to keep your architecture clean and effective. By the end, you’ll know to use platform events wisely without getting caught in the complexities they can create.

Key Takeaways

• What is the Platform Event Trap?: It’s a situation where the misuse of platform events leads to system complexity, performance issues, and maintenance headaches.
• Causes: Common causes include using events for simple tasks, creating complex chains of events, ignoring limits, and poor error handling.
• Warning Signs: Look out for slow performance, difficulty debugging, hitting platform limits, and systems that are hard to understand or change.
• Best Practices: To avoid the trap, use events for true asynchronous needs, keep designs simple, monitor usage, and have a solid error-handling plan.
• Alternatives: Sometimes, a different tool like Apex, Queueable Apex, or Batch Apex is a better fit for the job.

What Are Platform Events in Salesforce?

Before we dive into the trap, let’s quickly cover what platform events are. Think of them like announcements or notifications broadcast within your Salesforce environment. When something important happens—like a new order is placed—a platform event can be published. Other parts of your system, or even external applications, can “subscribe” to these events and react accordingly.

This system is built on an event-driven architecture, which means actions are triggered by events rather than direct commands. This approach is powerful because it decouples different components. Instead of one part of your code directly calling another, it simply sends out a message. Any system interested in that message can listen and act, without the sender needing to know who is listening. This design promotes flexibility and scalability, which are crucial for modern applications. For a deeper technical overview, the official Salesforce Platform Events documentation provides comprehensive details.

The Publisher-Subscriber Model

At its core, the platform event framework uses a publish-subscribe (or “pub-sub”) model.

• Publisher: The system or process that creates and sends the event message. For example, an order management system publishes an Order_Created__e event.
• Subscriber: The system or process that listens for specific event messages and takes action when one is received. For instance, an inventory system could subscribe to Order_Created__e events to update stock levels.

This separation is what makes the architecture so flexible. You can add new subscribers without changing the publisher, making it easy to extend your system’s functionality over time.

Defining the Platform Event Trap

The platform event trap occurs when developers rely too heavily on platform events for processes that could be handled more simply and efficiently by other means. It’s the digital equivalent of using a complex delivery system to pass a note to someone sitting in the same room. While the message gets delivered, the overhead is unnecessary and can lead to significant problems down the line.

This pitfall turns a useful tool into a source of complexity. Instead of creating a clean, decoupled architecture, you end up with a tangled web of events that are difficult to trace, debug, and maintain. Performance can suffer as the system struggles to process a high volume of unnecessary events, and you might start hitting the platform’s publishing and delivery limits, causing critical processes to fail. In essence, the very tool meant to simplify communication becomes a bottleneck.

Common Causes of Falling into the Trap

Several common missteps can lead a development team straight into the platform event trap. Recognising these patterns is key to avoiding them in your own projects.

Overusing Events for Synchronous Logic

One of the most frequent mistakes is using platform events for tasks that should be synchronous. If a process needs an immediate result before it can continue, an asynchronous event is the wrong tool. For example, if you need to validate a user’s input before saving a record, waiting for a platform event to return a validation result is inefficient. A direct Apex call would be faster and more straightforward. Using events in these scenarios adds unnecessary latency and complexity.

Creating Complex Event Chains

Another common issue is creating long, complicated chains of events, often called chained events. This happens when one event trigger publishes another event, which in turn publishes another, and so on. While this might seem logical at first, it can quickly create a system that is incredibly difficult to debug. If something breaks in the middle of the chain, tracing the problem back to its source becomes a major headache. These chains also make the system brittle; a failure at any single point can cause a cascade of failures.

Ignoring Platform Governance and Limits

Salesforce, like any platform, has limits on how many events you can publish and receive within a certain timeframe. These are known as governor limits. Teams that don’t monitor their event usage can easily hit these limits, especially as their application scales. When you exceed your allocation, the platform will stop processing your events, which can bring critical business processes to a halt. Ignoring these limits is a direct path to system instability.

Warning Signs: Are You in the Trap?

How can you tell if your application is falling victim to the platform event trap? There are several clear warning signs to watch out for.

• Degraded Performance: Your application feels sluggish, and processes take longer than they should. This can happen when the event bus is overloaded with too many events.
• Debugging Nightmares: When something goes wrong, it’s extremely difficult to find the root cause. You spend hours tracing events through logs to understand the sequence of actions.
• Frequently Hitting Limits: You receive regular notifications from Salesforce that you are approaching or have exceeded your platform event publishing or delivery allocations.
• Fragile System: Small changes in one part of the application cause unexpected failures in completely different areas. This is a classic symptom of overly complex and coupled event chains.
• Onboarding Difficulties: New developers on your team struggle to understand how the system works. The flow of data and logic is not intuitive because it’s hidden within a complex web of events.

Best Practices to Avoid the Platform Event Trap

Avoiding this pitfall is about discipline and good design. By following a few key principles, you can harness the power of platform events without creating a maintenance nightmare.

1. Use Events for Their Intended Purpose

Reserve platform events for what they do best: asynchronous communication between decoupled systems. They are perfect for notifications, integrations with external systems, and triggering processes that don’t need to happen immediately. Before implementing a platform event, ask yourself: Does this process truly need to be asynchronous? If the answer is no, consider a simpler alternative.

2. Keep Your Architecture Simple

Avoid creating long and complex event chains. Aim for a simple, flat architecture where possible. If a process requires multiple steps, consider orchestrating it with a tool designed for that purpose, like Flow Orchestrator or a custom Apex controller. A simpler design is easier to understand, test, and maintain. This approach aligns with the KISS (Keep It Simple, Stupid) principle, a design philosophy that is widely adopted in software engineering.

3. Implement Robust Error Handling and Logging

Things will go wrong. An external system might be down, or a record might be locked. Your design must account for this. Implement a retry mechanism for failed events. For example, if a subscriber fails to process an event, it could be republished or logged for manual intervention. Comprehensive logging is also essential. Make sure you log key information, like event IDs and outcomes, so you can easily trace and debug issues when they arise.

4. Monitor Your Event Usage

Keep a close eye on your platform event consumption. Use the Salesforce Optimiser and other monitoring tools to track how many events you’re publishing and subscribing to. Set up alerts to notify you when you are approaching your governor limits. Proactive monitoring allows you to address potential issues before they become critical failures. Regularly reviewing your usage can also highlight opportunities to optimise your architecture, as discussed in a recent report from NewsAsshop.

Alternatives to Platform Events

Platform events are a powerful tool, but they aren’t always the right one. Salesforce provides several other tools for handling different types of processing. Knowing when to use each is a hallmark of a skilled developer.

Understanding these alternatives is crucial. For example, if you need to perform a complex calculation on a set of records, Batch Apex is a much better choice than publishing thousands of individual platform events. Choosing the right tool for the job is the most effective way to avoid the platform event trap and build a healthy, scalable application.

Conclusion: Building Resilient Systems

Platform events are a fantastic feature for creating modern, event-driven applications on Salesforce. They enable a level of flexibility and scalability that is difficult to achieve with traditional methods. However, like any powerful tool, they must be used with care and intention.

By understanding what the platform event trap is and how it occurs, you can design your systems to avoid it. Always question whether an event is the right tool for the job. Strive for simple, easy-to-understand architectures, and build in robust monitoring and error handling from the start. By following these best practices, you can leverage the full power of platform events to build resilient, maintainable, and high-performing applications that will serve your business well for years to come. For more information on building robust systems, the concepts of resilience engineering detailed by institutions like Carnegie Mellon University can provide valuable insights.

FAQ

Q1: Can I use platform events to update records in Salesforce?
Yes, you can create an Apex trigger that subscribes to a platform event and then performs DML operations (like creating, updating, or deleting records) based on the event data.

Q2: What’s the difference between a platform event and a Change Data Capture event?
Platform events are custom notifications that you define and publish. They are great for broadcasting business processes. Change Data Capture (CDC) events are automatically published by Salesforce when a record is created, updated, deleted, or undeleted. CDC is specifically for data replication, whereas platform events are for more general-purpose communication.

Q3: How do I handle errors when a subscriber fails to process a platform event?
You can build a custom retry mechanism. For example, you can catch the exception in your subscriber trigger, log the failed event details to a custom object, and have a scheduled job that attempts to reprocess these failed events later.

Q4: Is there a way to guarantee the order of platform event processing?
No, platform event subscribers process events in a non-deterministic order. You cannot and should not design your system with the assumption that subscribers will run in a specific sequence.

Q5: How can I avoid the platform event trap when integrating with external systems?
When integrating, use events to notify the external system that something has happened, but don’t create complex chains. Let the external system call back into Salesforce via the API for more information if needed. This keeps the architecture cleaner and less prone to the platform event trap.