16 KiB
Architecture Research
Domain: Skill-based Workflow Orchestration System Researched: 2026-03-13 Confidence: HIGH
Standard Architecture
System Overview
技能型工作流编排系统采用分层架构,将处理逻辑、状态管理和执行协调分离。基于当前研究和行业最佳实践,推荐以下四层架构:
+---------------------------------------------------------------+
| Orchestration Layer |
| [Workflow Coordinator] [State Manager] [Error Handler] |
+---------------------------------------------------------------+
| Skill Definition Layer |
| [SKILL.md specs] [Schema Definitions] [Trigger Rules] |
+---------------------------------------------------------------+
| Execution Layer |
| [Platform Skills] [Processing Skills] [Analysis Skills] |
+---------------------------------------------------------------+
| Infrastructure Layer |
| [File System] [External APIs] [AI Services] [State Store] |
+---------------------------------------------------------------+
Component Responsibilities
| Component | Responsibility | Typical Implementation |
|---|---|---|
| Workflow Coordinator | 协调多个技能的执行顺序、依赖管理 | kb-workflow 主控模块 |
| State Manager | 步骤级状态持久化、断点续传支持 | workflow_state.json + 原子写入 |
| Error Handler | 错误分类、降级策略、重试逻辑 | 统一错误处理模块 |
| Skill Registry | 技能发现、能力声明、Schema 注册 | SKILL.md + JSON Schema |
| Platform Skills | 平台特定内容获取(B站/知乎) | kb-bilibili-, kb-zhihu- |
| Processing Skills | 内容转换(语音识别/OCR) | kb-whisper, kb-funasr, kb-ocr |
| Analysis Skills | AI 深度分析、报告生成 | kb-deep-analyzer |
Recommended Project Structure
kb-skills/
+-- skills/ # 技能模块目录
| +-- core/ # 核心基础设施
| | +-- state_manager.py # 状态管理
| | +-- schema_registry.py # Schema 注册
| | +-- pipeline.py # 管道执行引擎
| | +-- error_handler.py # 错误处理
| |
| +-- platforms/ # 平台技能
| | +-- bilibili/ # B站技能组
| | | +-- SKILL.md
| | | +-- metadata.py
| | | +-- content.py
| | +-- zhihu/ # 知乎技能组
| | +-- SKILL.md
| | +-- metadata.py
| | +-- content.py
| |
| +-- processing/ # 处理技能
| | +-- whisper/ # 语音识别
| | +-- funasr/ # 中文语音识别
| | +-- ocr/ # OCR 处理
| |
| +-- analysis/ # 分析技能
| +-- deep_analyzer/ # 深度分析
|
+-- schemas/ # JSON Schema 定义
| +-- workflow_state.schema.json
| +-- skill_output.schema.json
| +-- platform_metadata.schema.json
|
+-- workflows/ # 工作流定义
| +-- video_pipeline.yaml # 视频处理流程
| +-- article_pipeline.yaml # 文章处理流程
|
+-- cli.py # 统一 CLI 入口
+-- config.py # 配置管理
Structure Rationale
- skills/core/: 核心基础设施,所有技能共享的状态管理、Schema 验证和管道执行
- skills/platforms/: 按平台组织,每个平台有自己的元数据提取和内容下载技能
- skills/processing/: 内容转换技能,独立于平台
- skills/analysis/: AI 分析技能,作为管道的最后阶段
- schemas/: 统一的 JSON Schema 定义,确保接口一致性
- workflows/: 声明式工作流定义,指定技能组合和执行顺序
Architectural Patterns
Pattern 1: Pipeline Orchestration (管道编排)
What: 将处理流程建模为一系列串联的步骤,每个步骤接收输入、执行处理、产生输出。
When to use: 可预测的、重复性的任务,如内容处理管道。
Trade-offs:
- 优点:确定性执行、易于调试、支持断点续传
- 缺点:灵活性有限,不适合需要动态决策的场景
Example:
# Pipeline definition
class ContentPipeline:
steps = [
("parse", LinkParserSkill),
("metadata", MetadataSkill), # depends on parse
("download", ContentSkill), # depends on metadata
("transcribe", TranscribeSkill), # conditional: only for video
("analyze", AnalyzeSkill), # depends on download + transcribe
]
def run(self, url: str, state: WorkflowState):
for step_name, skill in self.steps:
if state.is_completed(step_name):
continue # Skip completed steps
result = skill.execute(state.get_step_input(step_name))
state.mark_completed(step_name, result)
if not result.success:
return self.handle_error(result.error)
Pattern 2: Step-Level State Management (步骤级状态管理)
What: 每个主要步骤完成后立即持久化状态,支持从任意断点恢复执行。
When to use: 长时间运行的批处理任务,可能因网络、API 限制等原因中断。
Trade-offs:
- 优点:断点续传、执行追踪、幂等性保证
- 缺点:状态管理开销、需要设计状态 Schema
Example:
# workflow_state.json
{
"url": "https://www.bilibili.com/video/BV1xx411c7mD",
"platform": "bilibili",
"content_type": "video",
"created_at": "2026-03-13T10:00:00Z",
"updated_at": "2026-03-13T10:15:00Z",
"steps": {
"parse": {
"status": "completed",
"output": {"video_id": "BV1xx411c7mD"},
"completed_at": "2026-03-13T10:00:05Z"
},
"metadata": {
"status": "completed",
"output": {"title": "...", "duration": 1800},
"completed_at": "2026-03-13T10:00:30Z"
},
"download": {
"status": "in_progress",
"output": null,
"started_at": "2026-03-13T10:01:00Z"
}
}
}
Pattern 3: Schema-First Interface Design (Schema 优先接口设计)
What: 先定义输入输出的 JSON Schema,再实现技能逻辑。所有技能遵守统一的接口规范。
When to use: 多人协作、需要接口稳定性和可测试性的项目。
Trade-offs:
- 优点:接口清晰、易于测试、支持自动验证
- 缺点:前期设计成本、Schema 维护负担
Example:
// schemas/skill_output.schema.json
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"required": ["success", "data"],
"properties": {
"success": {"type": "boolean"},
"data": {"type": "object"},
"error": {
"type": "object",
"properties": {
"code": {"type": "string"},
"message": {"type": "string"},
"detail": {"type": "string"}
}
},
"metadata": {
"type": "object",
"properties": {
"duration_ms": {"type": "number"},
"tokens_used": {"type": "number"}
}
}
}
}
Pattern 4: Idempotent Execution (幂等执行)
What: 相同输入重复执行产生相同结果,不会产生副作用(如重复文件)。
When to use: 任何可能需要重试的处理步骤。
Trade-offs:
- 优点:安全重试、简化错误恢复
- 缺点:需要设计去重逻辑
Example:
class ContentSkill:
def execute(self, input: dict) -> SkillOutput:
# Generate deterministic filename from input
content_hash = hashlib.sha256(input['url'].encode()).hexdigest()[:12]
output_path = self.get_output_dir() / f"{content_hash}.mp4"
# Check if already exists
if output_path.exists():
return SkillOutput(success=True, data={"path": str(output_path), "cached": True})
# Download content
self.download_content(input['url'], output_path)
return SkillOutput(success=True, data={"path": str(output_path), "cached": False})
Data Flow
Content Processing Pipeline
[URL Input]
|
v
+-------------+ +----------------+
| Link Parser | --> | Platform/Type |
+-------------+ | Detection |
+----------------+
|
+---------------+---------------+
| |
v v
+-------------+ +-------------+
| Bilibili | | Zhihu |
| Pipeline | | Pipeline |
+-------------+ +-------------+
| |
+------+------+ +-------+-------+
| | | |
v v v v
[Metadata] [Download] [Metadata] [Download]
| | | |
+------+------+ +-------+-------+
| |
v v
+-------------+ +-------------+
| Video? | | Article |
| - Whisper | | - Direct |
| - FunASR | | Extract |
| - OCR | +-------------+
+-------------+ |
| |
+---------------+--------------+
|
v
+-----------------+
| Deep Analyzer |
| (AI Analysis) |
+-----------------+
|
v
+-----------------+
| Archive to |
| Knowledge Base |
+-----------------+
State Management Flow
[Workflow Start]
|
v
+------------------+
| Load/Init State | <-- workflow_state.json
+------------------+
|
v
+------------------+ +------------------+
| For Each Step | --> | Check Status |
+------------------+ | - completed? skip|
| | - failed? retry |
v | - pending? run |
+------------------+ +------------------+
| Execute Step | |
+------------------+ v
| +------------------+
v | Mark Completed |
+------------------+ | Save State |
| Validate Output | -->| (atomic write) |
+------------------+ +------------------+
|
v
[Next Step / Complete]
Key Data Flows
- URL to Metadata: URL -> Link Parser -> (platform, type, id) -> Platform Metadata Skill -> Metadata JSON
- Metadata to Content: Metadata JSON -> Content Skill -> (video file / article text)
- Content to Transcript: Video File -> Transcribe Skill (Whisper/FunASR) -> Transcript JSON
- Content + Transcript to Analysis: Content + Transcript -> Deep Analyzer -> Analysis Report
Scaling Considerations
| Scale | Architecture Adjustments |
|---|---|
| 1-100 items/day | 当前架构足够,单进程执行 |
| 100-1000 items/day | 添加任务队列,并行处理独立任务 |
| 1000+ items/day | 分布式任务调度,API 请求限流,缓存层 |
Scaling Priorities
- First bottleneck: 外部 API 限流(B站/知乎)。解决方案:请求队列 + 指数退避重试
- Second bottleneck: AI 分析耗时。解决方案:批处理 + 并行分析
Anti-Patterns
Anti-Pattern 1: Global State Mutation
What people do: 在多个技能间共享可变全局状态
Why it's wrong: 难以追踪状态变化、难以测试、难以恢复
Do this instead: 每个步骤从 state 读取输入,将输出写回 state,状态变更通过 state manager 集中管理
Anti-Pattern 2: Implicit Dependencies
What people do: 技能之间通过隐式约定传递数据(如固定文件路径)
Why it's wrong: 脆弱的耦合,修改一个技能可能破坏其他技能
Do this instead: 在 workflow_state.json 中显式声明依赖关系,通过 state manager 传递数据
Anti-Pattern 3: Silent Failure
What people do: 捕获异常后只打印日志,继续执行
Why it's wrong: 下游步骤收到无效输入,产生难以调试的错误
Do this instead: 明确的失败处理策略 - 要么终止并记录,要么降级并提供默认值
Anti-Pattern 4: Non-Idempotent Operations
What people do: 每次执行都创建新文件(如 output_1.mp4, output_2.mp4)
Why it's wrong: 重试产生垃圾文件,磁盘占用增长
Do this instead: 基于输入生成确定性文件名,已存在则跳过
Integration Points
External Services
| Service | Integration Pattern | Notes |
|---|---|---|
| Bilibili API | HTTP + Cookie Auth | 需要 BILIBILI_COOKIE 环境变量 |
| Zhihu API | HTTP + Cookie Auth | 需要 ZHIHU_COOKIE 环境变量 |
| AI Provider | OpenAI-compatible API | 需要 AI_API_KEY 环境变量 |
| HuggingFace | API + Local Cache | 需要 HF_TOKEN 环境变量 |
| Git | Command Line | 需要 KB_GIT_USER/EMAIL 配置 |
Internal Boundaries
| Boundary | Communication | Notes |
|---|---|---|
| Orchestrator <-> Skills | JSON via stdin/stdout | 标准化输入输出格式 |
| Skills <-> State Manager | File I/O | workflow_state.json |
| Skills <-> External APIs | HTTP | 统一错误处理和重试 |
Build Order Implications
基于组件依赖关系,建议的构建顺序:
Phase 1: Foundation (基础设施)
- State Manager - 所有后续组件的基础
- Schema Registry - 定义统一的输入输出格式
- Error Handler - 统一错误处理模式
Phase 2: Core Skills (核心技能)
- Link Parser - 入口点,无依赖
- Platform Metadata Skills - 依赖 Link Parser 输出
- Platform Content Skills - 依赖 Metadata 输出
Phase 3: Processing Skills (处理技能)
- Whisper/FunASR - 依赖视频文件
- OCR Processor - 依赖视频截图
Phase 4: Analysis Skills (分析技能)
- Deep Analyzer - 依赖内容和转录文本
Phase 5: Orchestration (编排层)
- Pipeline Engine - 组合所有技能
- Workflow Definitions - 声明式流程定义
Sources
- AI Architecture Patterns 101: Workflows, Agents, MCPs, and A2A Systems - HIGH confidence, comprehensive pattern overview
- Data Pipeline Architecture: 5 Design Patterns with Examples - Dagster - HIGH confidence, pipeline patterns
- Agentic Workflows in 2026: The ultimate guide - Vellum - HIGH confidence, agent architecture patterns
- State of Open Source Workflow Orchestration Systems 2025 - MEDIUM confidence, ecosystem overview
- ML Pipeline Architecture Design Patterns - Neptune.ai - MEDIUM confidence, ML-specific patterns
Architecture research for: Skill-based Workflow Orchestration System Researched: 2026-03-13