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AWS Alternatives to gRPC

· 7 min read
Serhii Hrekov
Serhii Hrekov
software engineer, creator, artist, programmer, projects founder

AWS Alternatives to gRPC: Serverless Communication Patterns​

When building an application on AWS, especially using Lambda and other serverless components, the landscape for inter-service communication shifts dramatically compared to traditional VM-based or containerized microservices where gRPC shines.

While gRPC is possible to use with AWS Lambda (via HTTP/2 support in API Gateway or Application Load Balancer), the complexity of managing the gRPC framework within the Lambda execution environment often makes it non-ideal.

The fundamental shift in AWS is moving from synchronous RPC (Remote Procedure Call) patterns to more flexible Asynchronous Event-Driven and Managed API patterns.

1. Primary gRPC Alternatives on AWS​

The best alternatives depend entirely on the required communication pattern: synchronous request/response vs. asynchronous event stream.

Communication GoalAWS Recommended Service/PatternWhy it Replaces gRPC/REST
Synchronous API Gateway (Request/Response)API Gateway (REST or HTTP APIs)Managed service with authentication, throttling, and direct Lambda integration. Avoids running a long-lived gRPC server.
Asynchronous Pub/Sub (Event-Driven)SNS (Simple Notification Service) + SQS (Simple Queue Service)Highly scalable, durable, and reliable pattern where services communicate via events (gRPC handles communication, not workflow).
Data Streaming / Real-time EventsKinesis Data StreamsHandles massive, continuous real-time data ingestion for processing by downstream Lambdas or EC2 instances.
Service Integration / WorkflowAWS Step FunctionsDefines complex, multi-service workflows and orchestrates Lambda/ECS/EC2 calls, handling state and failure better than simple RPC.

2. AWS Communication Patterns: The Alternatives to REST/JSON​

While REST with JSON remains the default for external-facing APIs, within AWS, two high-performance alternatives replace JSON's role in serverless backends:

A. Asynchronous Events (SNS/SQS)​

This is the most common pattern for decoupling services in Lambda-based architectures.

  • Service A processes data and publishes a structured event message (often JSON, but the structure is the "contract") to an SNS Topic.

  • Service B has an SQS Queue subscribed to that Topic. The message is durable and Service B can consume it at its own pace.

  • Alternative to gRPC: Instead of calling a function in Service B (synchronous RPC), Service A announces that an event occurred, and Service B reacts. This is crucial for scalability and resiliency.

B. Protocol Buffers / Avro / Binary Payloads​

For high-volume, performance-critical Lambda integrations, you can use binary data formats within the asynchronous services.

  • Kinesis / SQS with Binary Payloads: Instead of sending JSON strings in SQS or Kinesis, the producer Lambda serializes data using Protocol Buffers (the same IDL gRPC uses) or Apache Avro.
  • Performance Benefit: The consuming Lambda (or other service) receives the highly compact binary payload. This dramatically reduces the payload size and the time spent on serialization/deserialization, achieving gRPC-level efficiency without the HTTP/2 overhead.

3. AWS Lambda and gRPC​

If you must use gRPC for compatibility or specific architectural reasons, here is how you would deploy it:

  • Serverless Option (API Gateway): Use an Application Load Balancer (ALB) with an attached Lambda, or use API Gateway HTTP API with a Lambda proxy integration.
    • The Problem: API Gateway and ALB handle the HTTP/2 connection, but the Lambda function is still short-lived. A true gRPC server is meant to be a long-running process, which conflicts with the Lambda model.
    • Workaround: The Lambda must implement the gRPC server logic (the Servicer) and correctly process the Protobuf payload passed via the proxy integration. This is complex and atypical.
  • Containerized Option (ECS/EKS): The most straightforward way to run a gRPC server is within a long-running service on Amazon ECS (Elastic Container Service) or Amazon EKS (Kubernetes).
    • Benefit: Here, you run your standard Python gRPC server, and communication between containers uses the high-performance gRPC standard. This is the closest alternative to a traditional gRPC deployment.

4. When to Stick to Simple REST/JSON (API Gateway)​

For synchronous, external-facing APIs, or simple internal APIs where latency isn't measured in milliseconds, REST remains the best choice due to its simplicity and ubiquity.

  • API Gateway REST API: Provides strong contracts, caching, throttling, and easy integration with Lambda, making it the default choice for modern, managed HTTP endpoints.

Summary: Choosing the Right AWS Pattern​

ScenarioRecommendationTransport/Data Format
External API (Public/Mobile)API Gateway (REST/HTTP) $\to$ LambdaJSON over HTTP/1.1 or HTTP/2
High-Volume Internal EventsSNS $\to$ SQS $\to$ LambdaStructured JSON or Binary Protobuf/Avro
Real-time Data StreamsKinesis Data Streams $\to$ LambdaBinary (Protobuf/Avro)
Traditional MicroservicesECS/EKS with gRPC $\to$ Load BalancerProtobuf over HTTP/2