CRISP: Critical Path Analysis for Microservice Architectures

CRISP: Critical Path Analysis for Microservice Architectures

摘要

Uber’s backend is an exemplar of microservice architecture. Each microservice is a small, individually deployable program performing a specific business logic (operation). The microservice architecture is a type of distributed computing system, which is suitable for independent deployments and scaling of software programs, and so is widely used across modern service-oriented industries. Uber has a few thousand microservices interacting with one another via remote procedure calls (RPC).

A service request arriving at an entry point (aka end-point) to the Uber backend systems undergoes multiple “hops” through numerous microservice operations before being fully serviced. The life of a request results in complex microservice interactions. These interactions are deeply nested, asynchronous, and invoke numerous other downstream operations. As a result of this complexity, it is very hard to identify which underlying service(s) contribute to the overall end-to-end latency experienced by a top-level request. Answering this question is critical in many situations, for example:

• Identifying optimization opportunities for a top-level microservice
• Identifying common bottleneck operations affecting many services
• Setting appropriate time-to-live values for downstream RPC calls
• Diagnosing outages and error conditions
• Capacity planning and reduction

While latency is one of the metrics of interest, other metrics such as time-to-live, error rates, etc., also fall in the scope.