Cloud Native Software Architecture

July 18, 2020  •  architecture , cloud

A personal cheatsheet/reference for cloud native software architecture.

architecture

how the components are assembled and organized. This will be done in a way that meets the quality attributes.

Key Questions

  • who are the users?
  • what devices and form factors will be used?
  • what is the context of their usage?
  • scale and growth?
  • who are the main actors in the system (domain objects - e.g. orders, products, etc.)?
  • data classifications (PII)?
  • data types and sizes (relation records, documents, media files, etc.)?
  • what is the time frame for delivery?
  • is there an existing product / SaaS / open-source / etc. that provides the solution or a portion / components of it
  • capacity estimation & constraints?
  • functional requirements?
  • Non Functional Requirements - Latency, Consistency, Availability, High Throughput, etc.
  • what is explicitly out of scope
  • organization and teams structure

see System Design: DoorDash — a prepared food delivery service for good reference

Organization Considerations

  • engineering (application & platform)
  • operations (application & platform)

Quality Attributes (*ities and friends)

  • reliability - ability to continue to operate under predefined conditions
  • availability - ratio of the available system time to the total working time
  • scalability - ability of the system to handle load increases without decreasing performance
  • efficiency
  • performance
  • security
  • cost
  • interoperability
  • correctness
  • maintainability
  • readability
  • extensibility
  • testability

Patterns

modern cloud native architecture patterns as of July 2020

event-sourcing

Capture all changes to an application state as a sequence of events.

Core Design Decisions

  • Domain Entities and Events
  • Event Content
    • each event stores delta state
    • each event stores full state
      • idempotent is easy to solve for duplicate events
  • Total Ordering (ordered stream of events - ledger)
    • ensure all event are processed in order. this is needed for causal relationships.
    • e.g. ordering matters for two messages related to the same entity

Resources

Hexagonal

the ports and adapters architecture. decouples core domain logic from specific storage, database, protocol, etc.

Resources

Topics / Concepts / Terms

Database

Shuffle Sharding

limits / isolates tenants in a multi-tenant system so they don’t negatively impact other tenants. method of assigning tenant to resources.

Resources

Constant Work

  • overprovision resources to the point where it would operate correctly even if an availability zone were to be unavailable
  • if AZ becomes unavailable, no new resources need to be provisioned, just a quick re-routing. you are essentially always operating the infrastructure for failure mode (active-active)

Resources

Canary

A canary release is a technique to reduce the risk from deploying a new version of software into production. A new version of software, referred to as the canary, is deployed to a small subset of users alongside the stable running version. Traffic is split between these two versions such that a portion of incoming requests are diverted to the canary. This approach can quickly uncover any problems with the new version without impacting the majority of users.

Resources

Resources

Books (oreilly.com)

Websites

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