Part 4: Building an engine and wrapper to support non Spring Boot apps

In Part 1, I introduced the idea behind the cloud-circuitbreaker — a distributed, annotation-driven circuit breaker backed by DynamoDB.
In Part 2, we walked through how failure detection, TTLs, and state tracking work.
In Part 3, we walked through how to integrate cloud circuit breaker with Lambda and Spring Boot.

Not all apps are Spring Boot right? Since this works only with annotations, I wanted something more.

So, I built something new.

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💡 Introducing cloud-circuitbreaker-engine

This is a cloud-native, distributed circuit breaker written in Java, backed by DynamoDB, and designed to be:

• Stateless on the instance
• Shared in behavior
• Easy to use with or without @CloudCircuitBreaker annotation
• Framework-agnostic, with support for Spring Boot, plain Java, and AWS Lambda

👉 View the source on GitHub

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✨ Example Usage

Here’s how you’d use it inside your service:

2. Initialize the Engine

CloudCircuitBreakerEngine engine = CloudCircuitBreakerEngine
    .builder()
    .withDynamoClient(AmazonDynamoDBClientBuilder.defaultClient())
    .withBreakerTable("circuit-breaker-table")
    .withTimeoutSeconds(10)
    .withFailureThreshold(3)
    .withTTLSeconds(30)
    .build();

You can customize all circuit breaker parameters: timeouts, thresholds, TTL, and more.

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3. Wrap Your Function

Now wrap your function using the engine:

String result = engine.execute(
    "user-service-call",
    () -> externalService.callUserService(userId),
    () -> cachedUserService.readFromCache(userId)
);

This works just like the annotation — but under your full control.

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💡 Why Use This Over Annotations?

If you’re in a:

• CLI app
• Lightweight microservice with manual wiring
• Kotlin/Scala or non-Spring ecosystem
• Testing environment or framework plugin

…then this gives you the same power as @CloudCircuitBreaker, but without dependency on Spring or reflection.

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🧪 Testing It

Here’s a full testable example:

CloudCircuitBreakerEngine engine = CloudCircuitBreakerEngine
    .builder()
    .withDynamoClient(dynamoClient)
    .withBreakerTable("cb-table")
    .build();

String result = engine.execute(
    "external-fetch",
    () -> unstableAPI.getUser("123"),
    () -> "fallback-user"
);

Failures are automatically recorded in DynamoDB. If threshold is breached, fallback is called until TTL expires.

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🏁 That’s a Wrap

That concludes the series on building and using a distributed circuit breaker for cloud-native apps.

Whether you’re building resilient APIs in Spring Boot, handling retries in Lambdas, or writing lightweight CLI tools, cloud-circuitbreaker gives you:

• A shared view of failures across all instances
• TTL-based breaker state stored in DynamoDB
• A clean, ergonomic API — with or without Spring

Thanks for following along this far!
This was a problem I personally faced at scale — and building this library made it dramatically easier to handle edge cases, retries, and chaos in production.

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📬 Got Ideas?

I’m planning Redis support, metrics emitters, and maybe a dashboard.

Open an issue or connect on LinkedIn — I’d love to hear how you’d like to use this.

Until next time,
Happy breaking (responsibly).