微服务绞杀者模式迁移架构

Architecture

绞杀者模式迁移架构图，展示使用路由层在新旧系统之间分流流量，逐步用新微服务替换遗留单体应用。该模板模拟经过验证的迁移策略，新功能作为微服务构建，遗留端点逐步退役。对于在不进行高风险大爆炸重写的情况下现代化遗留系统的团队至关重要。

完整 FlowZap 代码

Client { # Client
n1: circle label:"User Request"
n2: rectangle label:"Anti-Corruption Layer"
n3: rectangle label:"Receive Response"
n4: circle label:"End"
n1.handle(right) -> n2.handle(left)
n2.handle(bottom) -> Router.n5.handle(top) [label="Translate"]
n3.handle(right) -> n4.handle(left)
}
Router { # Strangler Fig Router
n5: rectangle label:"Inspect Request Path"
n6: diamond label:"Migrated Endpoint?"
n7: rectangle label:"Route to New Service"
n8: rectangle label:"Route to Legacy Monolith"
n9: rectangle label:"Log Migration Metrics"
n5.handle(right) -> n6.handle(left)
n6.handle(right) -> n7.handle(left) [label="Yes"]
n6.handle(bottom) -> n8.handle(top) [label="No"]
n7.handle(bottom) -> NewServices.n10.handle(top) [label="Forward"]
n8.handle(bottom) -> Legacy.n14.handle(top) [label="Forward"]
n7.handle(right) -> n9.handle(left) [label="Track"]
n8.handle(right) -> n9.handle(left) [label="Track"]
}
NewServices { # New Microservices
n10: rectangle label:"Process in New Service"
n11: rectangle label:"New Service Database"
n12: rectangle label:"Publish Domain Event"
n13: rectangle label:"Return Response"
n10.handle(right) -> n11.handle(left) [label="Query"]
n11.handle(right) -> n12.handle(left) [label="Write"]
n12.handle(right) -> n13.handle(left)
n13.handle(top) -> Client.n3.handle(bottom) [label="New Response"]
}
Legacy { # Legacy Monolith
n14: rectangle label:"Process in Monolith"
n15: rectangle label:"Legacy Database"
n16: rectangle label:"Return Legacy Response"
n14.handle(right) -> n15.handle(left) [label="SQL"]
n15.handle(right) -> n16.handle(left) [label="Result"]
n16.handle(top) -> Client.n3.handle(bottom) [label="Legacy Response"]
}

为什么需要这个工作流？

Big-bang monolith rewrites fail 70% of the time due to scope creep, feature parity gaps, and business disruption. The strangler fig pattern enables incremental migration by routing traffic between the legacy monolith and new microservices, allowing teams to migrate one endpoint at a time with zero downtime and instant rollback capability.

工作原理

Step 1: A routing layer (strangler fig router) is placed in front of the legacy monolith.
Step 2: New features are built as microservices instead of adding to the monolith.
Step 3: The router inspects each request path and decides whether to forward to the new service or the legacy system.
Step 4: An anti-corruption layer translates between old and new data formats.
Step 5: Migration metrics track the percentage of traffic handled by new services.
Step 6: Legacy endpoints are retired once the new service is stable and fully tested.

替代方案

Big-bang rewrites are risky and expensive. Running parallel systems without a router creates confusion. Branch-by-abstraction works for libraries but not for services. This template visualizes the proven incremental migration strategy.

Key Facts

Template Name	微服务绞杀者模式迁移架构
Category	Architecture
Steps	6 workflow steps
Format	FlowZap Code (.fz file)