无服务器 API 后端架构

Architecture

无服务器 API 后端架构图，展示 API 网关、Lambda 授权函数、业务逻辑函数以及包括 DynamoDB、S3、SQS 和 SNS 在内的托管云服务，实现完全托管、自动扩展的后端。该模板模拟无服务器优先方法，完全消除基础设施管理，按调用付费并自动缩放至零。对于构建经济高效的事件驱动 API 后端的初创公司和团队至关重要。

下载 .fz 文件

完整 FlowZap 代码

Client { # Client Application
n1: circle label:"API Request"
n2: rectangle label:"API Gateway (AWS/Azure)"
n3: rectangle label:"Receive Response"
n4: circle label:"End"
n1.handle(right) -> n2.handle(left)
n2.handle(bottom) -> Functions.n5.handle(top) [label="Invoke Lambda"]
n3.handle(right) -> n4.handle(left)
}
Functions { # Serverless Functions
n5: rectangle label:"Auth Authorizer Lambda"
n6: diamond label:"Token Valid?"
n7: rectangle label:"Business Logic Lambda"
n8: rectangle label:"Return 401"
n9: rectangle label:"Data Validation Lambda"
n10: rectangle label:"Response Formatter"
n5.handle(right) -> n6.handle(left)
n6.handle(right) -> n7.handle(left) [label="Authorized"]
n6.handle(bottom) -> n8.handle(top) [label="Denied"]
n7.handle(right) -> n9.handle(left) [label="Process"]
n9.handle(right) -> n10.handle(left) [label="Validated"]
n8.handle(top) -> Client.n3.handle(bottom) [label="401"]
n10.handle(top) -> Client.n3.handle(bottom) [label="200 JSON"]
n7.handle(bottom) -> ManagedServices.n11.handle(top) [label="Read/Write"]
}
ManagedServices { # Managed Cloud Services
n11: rectangle label:"DynamoDB / CosmosDB"
n12: rectangle label:"S3 Object Storage"
n13: rectangle label:"SQS Message Queue"
n14: rectangle label:"SNS Notification"
n15: rectangle label:"CloudWatch Logs"
n11.handle(right) -> n12.handle(left) [label="Store Assets"]
n13.handle(right) -> n14.handle(left) [label="Trigger"]
n14.handle(top) -> Functions.n7.handle(bottom) [label="Async Invoke"]
n15.handle(top) -> Functions.n10.handle(bottom) [label="Log"]
}

为什么需要这个工作流？

Provisioning and managing servers for API backends is expensive and wasteful—most APIs have variable traffic with long idle periods. A serverless API backend eliminates infrastructure management entirely, with automatic scaling from zero to thousands of concurrent requests and pay-per-invocation pricing.

工作原理

Step 1: Client requests arrive at the API Gateway which handles routing and throttling.
Step 2: A Lambda authorizer validates JWT tokens before the request reaches business logic.
Step 3: Business logic Lambda functions process the request and interact with managed services.
Step 4: DynamoDB provides single-digit millisecond reads/writes without capacity planning.
Step 5: SQS and SNS handle asynchronous processing and notifications.
Step 6: CloudWatch provides logging and monitoring for all Lambda invocations.

替代方案

Container-based backends (ECS/Fargate) offer more control but require capacity planning. Traditional servers provide predictable performance but waste resources during idle periods. This template shows the fully serverless approach for maximum cost efficiency.

Key Facts

Template Name	无服务器 API 后端架构
Category	Architecture
Steps	6 workflow steps
Format	FlowZap Code (.fz file)