虚拟化技术在智能体工作流中的延迟与吞吐权衡及调优

2900559190
2026年02月16日
更新于 2026年02月17日
3 次阅读
摘要:本文深入探讨了在容器化(虚拟化)环境中部署与运行智能体工作流时,面临的延迟与吞吐量之间的核心权衡问题。通过构建一个完整的、可运行的示例项目,我们展示了一个智能体工作流引擎在Docker容器环境下的实现。项目重点演示了如何通过一个动态资源调度器,根据工作流负载和SLO(服务水平目标)实时调整容器的CPU与内存限制,从而在低延迟处理与高吞吐批处理之间寻找最优解。文章包含了项目架构、核心代码实现、性能监...

摘要

本文深入探讨了在容器化(虚拟化)环境中部署与运行智能体工作流时,面临的延迟与吞吐量之间的核心权衡问题。通过构建一个完整的、可运行的示例项目,我们展示了一个智能体工作流引擎在Docker容器环境下的实现。项目重点演示了如何通过一个动态资源调度器,根据工作流负载和SLO(服务水平目标)实时调整容器的CPU与内存限制,从而在低延迟处理与高吞吐批处理之间寻找最优解。文章包含了项目架构、核心代码实现、性能监控方案以及具体的调优实践,为开发者在实际场景中优化智能体系统性能提供了可借鉴的蓝本。

1. 项目概述与设计思路

在基于微服务或函数即服务(FaaS)的智能体系统中,每个智能体(Agent)或其关键组件(如推理引擎、工具执行器)常被部署在独立的虚拟化环境(如容器、微型虚拟机)中。这种隔离带来了安全性、可维护性和弹性伸缩的优势,但也引入了额外的开销,主要体现在:

  1. 虚拟化层开销:容器引擎(如Docker)、编排器(如Kubernetes)本身消耗的CPU和内存资源。
  2. 资源限制的副作用:为容器设置的CPU份额(cpu-shares)和内存上限(memory limit)虽然防止了资源侵占,但在请求突发时,可能因资源不足导致处理延迟增加,甚至因OOM(内存不足)被杀死。
  3. 网络与I/O虚拟化:容器间的通信、与宿主机或外部服务的I/O可能经过额外的虚拟网络层,增加延迟。

本项目旨在构建一个概念验证系统,模拟智能体工作流在容器化环境中的执行,并实现一个动态资源调度器来调优延迟与吞吐。核心设计思路如下:

  • 虚拟化环境抽象层:定义统一的接口来管理"执行单元"(对应一个容器),包括创建、执行任务、获取状态和设置资源限制。这允许我们未来轻松切换底层虚拟化技术(如从Docker切换到gVisorKata Containers)。
  • 智能体工作流引擎:负责解析和执行一个简单的多步骤智能体工作流。每个步骤由一个特定的"技能"(Skill)在独立的执行单元中完成。
  • 资源调度器:系统的"大脑"。它监控工作流队列长度、任务处理延迟等指标,并根据预设的调优策略(如"偏向低延迟"或"偏向高吞吐")动态调整每个执行单元的资源配额。
  • 监控与可视化:集成Prometheus客户端来暴露关键指标(延迟、吞吐、资源使用率),并可通过Grafana进行可视化,为调优决策提供数据支撑。

通过运行此项目,开发者可以直观地观察到:

  • 在严格资源限制下,系统吞吐量受限,但资源利用率高;任务排队导致尾部延迟激增。
  • 放宽资源限制可以减少延迟,但可能导致资源闲置,单位资源吞吐下降。
  • 动态调度器如何根据实时负载在两者间取得平衡。

2. 项目结构树

agent-virt-tuning/
├── requirements.txt
├── config.yaml
├── scheduler/
   ├── __init__.py
   └── dynamic_scheduler.py
├── virtualization/
   ├── __init__.py
   ├── base.py
   └── docker_env.py
├── workflow/
   ├── __init__.py
   ├── engine.py
   └── skills.py
├── monitor/
   ├── __init__.py
   └── metrics.py
├── main.py
├── run_workload.py
└── tests/
    ├── __init__.py
    ├── test_scheduler.py
    └── test_workflow.py

3. 核心代码实现

文件路径: requirements.txt

docker>=6.0.0
pyyaml>=5.4
prometheus-client>=0.17.0
numpy>=1.21.0
pytest>=7.0.0

文件路径: config.yaml

virtualization:
  type: "docker"  # 未来可扩展为 'gvisor', 'kata'
  docker:
    base_image: "python:3.9-slim"
    network: "agent-network"

workflow:
  max_queue_size: 100
  default_timeout_seconds: 30

scheduler:
  update_interval_seconds: 10
  latency_slo_milliseconds: 500  # 延迟服务水平目标
  strategy: "balanced"  # 可选: latency_first, throughput_first, balanced
  resource_adjustment:
    cpu_step: 0.2  # 每次调整CPU份额的步长(核心数)
    memory_step_mb: 128  # 每次调整内存的步长(MB)
    min_cpu: 0.5
    max_cpu: 4.0
    min_memory_mb: 256
    max_memory_mb: 2048

monitoring:
  prometheus_port: 8000

文件路径: virtualization/base.py

"""
虚拟化环境抽象基类定义。
"""
from abc import ABC, abstractmethod
from typing import Any, Dict, Optional
from dataclasses import dataclass

@dataclass
class ResourceSpec:
    """资源规格定义"""
    cpu_limit: float  # CPU核心数
    memory_limit_mb: int  # 内存限制(MB)

class ExecutionUnit(ABC):
    """执行单元抽象类,代表一个隔离的运行环境(如容器)"""

    def __init__(self, unit_id: str, resource_spec: ResourceSpec):
        self.unit_id = unit_id
        self.resource_spec = resource_spec
        self.status = "created"  # created, running, stopped, error

    @abstractmethod
    async def start(self):
        """启动执行单元"""
        pass

    @abstractmethod
    async def execute(self, command: str, input_data: str = "") -> Dict[str, Any]:
        """
        在执行单元内执行命令或调用。
        返回字典,至少包含 'success', 'output', 'error', 'execution_time_ms' 键。
        """
        pass

    @abstractmethod
    async def update_resources(self, new_spec: ResourceSpec) -> bool:
        """动态更新资源限制"""
        pass

    @abstractmethod
    async def stop(self):
        """停止并清理执行单元"""
        pass

class VirtualizationEnv(ABC):
    """虚拟化环境管理器抽象类"""

    @abstractmethod
    async def create_unit(self, unit_id: str, resource_spec: ResourceSpec, **kwargs) -> ExecutionUnit:
        """创建一个新的执行单元"""
        pass

    @abstractmethod
    async def list_units(self) -> Dict[str, ExecutionUnit]:
        """获取所有执行单元"""
        pass

文件路径: virtualization/docker_env.py

"""
基于Docker的虚拟化环境实现。
"""
import docker
import asyncio
from typing import Dict, Any
from .base import VirtualizationEnv, ExecutionUnit, ResourceSpec
from concurrent.futures import ThreadPoolExecutor

class DockerExecutionUnit(ExecutionUnit):
    """Docker容器执行单元"""

    def __init__(self, unit_id: str, resource_spec: ResourceSpec, container):
        super().__init__(unit_id, resource_spec)
        self._container = container
        self._docker_client = docker.from_env()
        self._thread_pool = ThreadPoolExecutor(max_workers=2)

    async def start(self):
        loop = asyncio.get_event_loop()
        await loop.run_in_executor(self._thread_pool, self._container.start)
        self.status = "running"

    async def execute(self, command: str, input_data: str = "") -> Dict[str, Any]:
        import time
        start_time = time.time()
        result = {"success": False, "output": "", "error": "", "execution_time_ms": 0}

        try:
            # 在容器内执行命令。这是一个简化示例,实际中可能需要更复杂的交互。
            exec_id = await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._docker_client.api.exec_create(
                    self._container.id,
                    cmd=['sh', '-c', f'echo "{input_data[:100]}" | {command}'],  # 简单管道模拟输入
                    stdout=True,
                    stderr=True
                )
            )
            exec_output = await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._docker_client.api.exec_start(exec_id['Id'], stream=False)
            )
            exec_inspect = await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._docker_client.api.exec_inspect(exec_id['Id'])
            )

            result['output'] = exec_output.decode('utf-8') if isinstance(exec_output, bytes) else exec_output
            result['success'] = (exec_inspect['ExitCode'] == 0)
            if not result['success']:
                result['error'] = f"Exit code: {exec_inspect['ExitCode']}"
        except Exception as e:
            result['error'] = str(e)

        result['execution_time_ms'] = int((time.time() - start_time) * 1000)
        return result

    async def update_resources(self, new_spec: ResourceSpec) -> bool:
        try:
            # Docker容器资源更新(需要容器在运行状态)
            update_config = docker.types.Resources(
                cpu_quota=int(new_spec.cpu_limit * 100000),  # 将核心数转换为微秒配额
                cpu_period=100000,
                mem_limit=f"{new_spec.memory_limit_mb}m"
            )
            await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._container.update(**update_config)
            )
            self.resource_spec = new_spec
            return True
        except Exception:
            return False

    async def stop(self):
        try:
            await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._container.stop(timeout=5)
            )
        except Exception:
            pass
        try:
            await asyncio.get_event_loop().run_in_executor(
                self._thread_pool,
                lambda: self._container.remove()
            )
        except Exception:
            pass
        self.status = "stopped"
        self._thread_pool.shutdown(wait=False)

class DockerVirtualizationEnv(VirtualizationEnv):
    """Docker环境管理器"""

    def __init__(self, config: Dict[str, Any]):
        self._client = docker.from_env()
        self._config = config
        self._units: Dict[str, DockerExecutionUnit] = {}
        # 确保网络存在
        self._ensure_network()

    def _ensure_network(self):
        network_name = self._config['docker']['network']
        try:
            self._client.networks.get(network_name)
        except docker.errors.NotFound:
            self._client.networks.create(network_name, driver="bridge")

    async def create_unit(self, unit_id: str, resource_spec: ResourceSpec, **kwargs) -> DockerExecutionUnit:
        # 构建容器创建配置
        container_config = {
            'image': self._config['docker']['base_image'],
            'command': 'tail -f /dev/null',  # 保持容器运行
            'detach': True,
            'name': f'agent-unit-{unit_id}',
            'network': self._config['docker']['network'],
            'cpu_quota': int(resource_spec.cpu_limit * 100000),
            'cpu_period': 100000,
            'mem_limit': f'{resource_spec.memory_limit_mb}m',
            'environment': ['PYTHONUNBUFFERED=1'],
        }
        container = await asyncio.get_event_loop().run_in_executor(
            None, lambda: self._client.containers.create(**container_config)
        )
        unit = DockerExecutionUnit(unit_id, resource_spec, container)
        self._units[unit_id] = unit
        return unit

    async def list_units(self) -> Dict[str, DockerExecutionUnit]:
        return self._units.copy()

文件路径: workflow/skills.py

"""
定义智能体工作流中可用的技能(Skill)。
每个技能映射到执行单元中的一个命令或调用。
"""
from typing import Dict, Any

class Skill:
    def __init__(self, name: str, command: str, estimated_resource: Dict[str, Any]):
        self.name = name
        self.command = command
        self.estimated_resource = estimated_resource  # 预估资源消耗,e.g., {'cpu': 0.5, 'memory_mb': 200}

# 预定义的技能库
SKILL_REGISTRY = {
    "text_processor": Skill(
        name="text_processor",
        command="python -c \"import sys; data=sys.stdin.read().strip(); print(f'Processed: {data.upper()} [{len(data)} chars]')\"",
        estimated_resource={'cpu': 0.3, 'memory_mb': 150}
    ),
    "ai_inference": Skill(
        name="ai_inference",
        # 模拟一个轻量级AI推理,实际中会调用模型服务
        command="python -c \"import time, sys, random; data=sys.stdin.read(); time.sleep(random.uniform(0.05, 0.2)); print(f'AI Result for <<{data[:20]}...>>: score={random.random():.2f}')\"",
        estimated_resource={'cpu': 1.5, 'memory_mb': 800}
    ),
    "data_aggregator": Skill(
        name="data_aggregator",
        command="python -c \"import sys, json; inputs = [line.strip() for line in sys.stdin if line]; print(f'Aggregated {len(inputs)} items: {inputs[-1][:50]}...')\"",
        estimated_resource={'cpu': 0.2, 'memory_mb': 100}
    )
}

文件路径: workflow/engine.py

"""
智能体工作流引擎。
负责编排技能在执行单元中的执行顺序。
"""
import asyncio
import uuid
from typing import List, Dict, Any, Optional
from datetime import datetime
from ..virtualization.base import VirtualizationEnv, ExecutionUnit, ResourceSpec
from .skills import SKILL_REGISTRY, Skill

class WorkflowStep:
    def __init__(self, skill_name: str, input_data: str = ""):
        self.skill_name = skill_name
        self.input_data = input_data
        self.skill: Optional[Skill] = SKILL_REGISTRY.get(skill_name)
        self.result: Optional[Dict[str, Any]] = None
        self.execution_unit: Optional[ExecutionUnit] = None

class WorkflowInstance:
    """一个工作流执行实例"""
    def __init__(self, wf_id: str, steps: List[WorkflowStep]):
        self.id = wf_id
        self.steps = steps
        self.status = "pending"  # pending, running, completed, failed
        self.start_time: Optional[datetime] = None
        self.end_time: Optional[datetime] = None
        self.final_output: Optional[str] = None

class WorkflowEngine:
    def __init__(self, virt_env: VirtualizationEnv, max_queue_size: int = 100):
        self.virt_env = virt_env
        self.max_queue_size = max_queue_size
        self.pending_queue: asyncio.Queue[WorkflowInstance] = asyncio.Queue(maxsize=max_queue_size)
        self.active_instances: Dict[str, WorkflowInstance] = {}
        self._unit_skill_map: Dict[str, str] = {}  # unit_id -> skill_name
        self._skill_unit_pool: Dict[str, List[ExecutionUnit]] = {}  # skill_name -> list of units
        self._lock = asyncio.Lock()

    async def _ensure_unit_for_skill(self, skill_name: str, resource_spec: ResourceSpec) -> ExecutionUnit:
        """确保某个技能有可用的执行单元,如果没有则创建"""
        async with self._lock:
            if skill_name not in self._skill_unit_pool:
                self._skill_unit_pool[skill_name] = []
            pool = self._skill_unit_pool[skill_name]

            for unit in pool:
                if unit.status == "running":
                    return unit

            # 没有空闲单元,创建新的
            unit_id = f"{skill_name}-{uuid.uuid4().hex[:8]}"
            unit = await self.virt_env.create_unit(unit_id, resource_spec)
            await unit.start()
            self._unit_skill_map[unit.unit_id] = skill_name
            pool.append(unit)
            return unit

    async def submit_workflow(self, steps_def: List[Dict[str, Any]]) -> str:
        """提交一个工作流,返回工作流ID"""
        if self.pending_queue.full():
            raise RuntimeError("Workflow queue is full")

        steps = [WorkflowStep(step_def['skill'], step_def.get('input', '')) for step_def in steps_def]
        wf_id = f"wf-{uuid.uuid4().hex[:8]}"
        instance = WorkflowInstance(wf_id, steps)
        await self.pending_queue.put(instance)
        self.active_instances[wf_id] = instance
        return wf_id

    async def _execute_step(self, step: WorkflowStep) -> bool:
        """执行单个步骤"""
        if not step.skill:
            step.result = {'success': False, 'error': f"Skill '{step.skill_name}' not found"}
            return False

        # 根据技能预估的资源需求创建或获取执行单元
        est = step.skill.estimated_resource
        resource_spec = ResourceSpec(
            cpu_limit=est['cpu'],
            memory_limit_mb=est['memory_mb']
        )
        try:
            unit = await self._ensure_unit_for_skill(step.skill_name, resource_spec)
            step.execution_unit = unit
            step.result = await unit.execute(step.skill.command, step.input_data)
            return step.result['success']
        except Exception as e:
            step.result = {'success': False, 'error': str(e)}
            return False

    async def process_workflow(self, instance: WorkflowInstance):
        """处理一个工作流实例"""
        instance.status = "running"
        instance.start_time = datetime.utcnow()
        step_outputs = []

        for step in instance.steps:
            success = await self._execute_step(step)
            step_outputs.append(step.result.get('output', '') if success else f"Error: {step.result.get('error')}")
            if not success:
                instance.status = "failed"
                break

        if instance.status == "running":
            instance.status = "completed"
            instance.final_output = " | ".join(step_outputs)
        instance.end_time = datetime.utcnow()
        # 从活跃实例中移除
        self.active_instances.pop(instance.id, None)

    async def run(self):
        """启动工作流引擎处理循环"""
        print("Workflow engine started.")
        while True:
            try:
                instance = await self.pending_queue.get()
                asyncio.create_task(self.process_workflow(instance))
            except asyncio.CancelledError:
                break
            except Exception as e:
                print(f"Error processing workflow from queue: {e}")

文件路径: scheduler/dynamic_scheduler.py

"""
动态资源调度器。
根据监控指标调整执行单元的资源限制。
"""
import asyncio
import time
from typing import Dict, Any, List
from dataclasses import dataclass
from ..virtualization.base import VirtualizationEnv, ResourceSpec
from ..workflow.engine import WorkflowEngine
from ..monitor.metrics import workflow_latency_histogram, workflow_throughput_counter, resource_usage_gauge

@dataclass
class SchedulerMetrics:
    avg_latency_ms: float
    throughput_per_min: float
    queue_length: int
    unit_resources: Dict[str, ResourceSpec]  # unit_id -> current resource

class DynamicResourceScheduler:
    def __init__(self, virt_env: VirtualizationEnv, workflow_engine: WorkflowEngine, config: Dict[str, Any]):
        self.virt_env = virt_env
        self.engine = workflow_engine
        self.config = config['scheduler']
        self.metrics_history: List[SchedulerMetrics] = []
        self._is_running = False

    async def collect_metrics(self) -> SchedulerMetrics:
        """收集当前系统指标"""
        # 注意:这是一个简化的实现。在实际系统中,这些指标应从监控模块实时获取。
        # 这里我们模拟计算。
        avg_latency = 500.0  # 默认值,应从 histogram 计算
        throughput = 10.0    # 默认值,应从 counter 计算
        queue_length = self.engine.pending_queue.qsize()

        units = await self.virt_env.list_units()
        unit_resources = {uid: unit.resource_spec for uid, unit in units.items()}

        # 更新Prometheus指标(模拟)
        workflow_latency_histogram.labels(strategy=self.config['strategy']).observe(avg_latency / 1000.0) # 转换为秒
        workflow_throughput_counter.labels(strategy=self.config['strategy']).inc(int(throughput))
        for uid, spec in unit_resources.items():
            resource_usage_gauge.labels(unit_id=uid, resource_type='cpu').set(spec.cpu_limit)
            resource_usage_gauge.labels(unit_id=uid, resource_type='memory_mb').set(spec.memory_limit_mb)

        return SchedulerMetrics(avg_latency, throughput, queue_length, unit_resources)

    def _make_decision(self, metrics: SchedulerMetrics) -> Dict[str, ResourceSpec]:
        """基于指标和策略做出资源调整决策"""
        decisions = {}
        strategy = self.config['strategy']
        latency_slo = self.config['latency_slo_milliseconds']
        adj = self.config['resource_adjustment']

        # 简化决策逻辑:
        # 1. 如果平均延迟 > SLO,倾向于增加资源(尤其是高CPU消耗的技能)。
        # 2. 如果队列过长,增加资源以提升吞吐。
        # 3. 根据策略调整激进程度。
        scale_factor = 1.0
        if strategy == "latency_first":
            scale_factor = 1.5  # 更积极地增加资源以降低延迟
        elif strategy == "throughput_first":
            scale_factor = 0.7  # 更保守,容忍更高延迟以节省资源

        for unit_id, current_spec in metrics.unit_resources.items():
            new_cpu = current_spec.cpu_limit
            new_mem = current_spec.memory_limit_mb

            # 决策示例:如果延迟超标,增加CPU
            if metrics.avg_latency_ms > latency_slo:
                new_cpu = min(current_spec.cpu_limit + adj['cpu_step'] * scale_factor, adj['max_cpu'])
            elif metrics.avg_latency_ms < latency_slo * 0.7 and metrics.queue_length < 5:
                # 延迟很低且队列空闲,可以适当缩减资源
                new_cpu = max(current_spec.cpu_limit - adj['cpu_step'] * 0.5, adj['min_cpu'])

            # 内存调整逻辑(示例):根据CPU比例调整
            cpu_ratio = new_cpu / current_spec.cpu_limit if current_spec.cpu_limit > 0 else 1.0
            new_mem = int(min(max(current_spec.memory_limit_mb * cpu_ratio, adj['min_memory_mb']), adj['max_memory_mb']))

            if abs(new_cpu - current_spec.cpu_limit) > 0.05 or abs(new_mem - current_spec.memory_limit_mb) > 10:
                decisions[unit_id] = ResourceSpec(cpu_limit=round(new_cpu, 2), memory_limit_mb=new_mem)

        return decisions

    async def _apply_decisions(self, decisions: Dict[str, ResourceSpec]):
        """应用资源调整决策到对应的执行单元"""
        units = await self.virt_env.list_units()
        for unit_id, new_spec in decisions.items():
            if unit_id in units:
                unit = units[unit_id]
                success = await unit.update_resources(new_spec)
                if success:
                    print(f"Scheduler: Updated {unit_id} resources to CPU={new_spec.cpu_limit}, Mem={new_spec.memory_limit_mb}MB")

    async def run_scheduling_loop(self):
        """调度器主循环"""
        self._is_running = True
        interval = self.config['update_interval_seconds']
        print(f"Dynamic scheduler started with strategy '{self.config['strategy']}', interval {interval}s.")

        while self._is_running:
            try:
                await asyncio.sleep(interval)
                metrics = await self.collect_metrics()
                self.metrics_history.append(metrics)
                # 保留最近100条记录
                if len(self.metrics_history) > 100:
                    self.metrics_history.pop(0)

                decisions = self._make_decision(metrics)
                if decisions:
                    await self._apply_decisions(decisions)

            except asyncio.CancelledError:
                break
            except Exception as e:
                print(f"Scheduler loop error: {e}")

    def stop(self):
        self._is_running = False

文件路径: monitor/metrics.py

"""
Prometheus指标定义与暴露。
"""
from prometheus_client import start_http_server, Histogram, Counter, Gauge
import yaml

# 加载配置
with open('config.yaml', 'r') as f:
    config = yaml.safe_load(f)
prom_port = config['monitoring']['prometheus_port']

# 定义指标
workflow_latency_histogram = Histogram(
    'workflow_latency_seconds',
    'Latency of completed workflows in seconds',
    ['strategy']
)

workflow_throughput_counter = Counter(
    'workflow_throughput_total',
    'Total number of completed workflows',
    ['strategy']
)

resource_usage_gauge = Gauge(
    'execution_unit_resource',
    'Current resource allocation of an execution unit',
    ['unit_id', 'resource_type']  # resource_type: 'cpu' or 'memory_mb'
)

def start_monitoring_server():
    """启动Prometheus指标HTTP服务器"""
    start_http_server(prom_port)
    print(f"Monitoring server started on port {prom_port}")

文件路径: main.py

"""
项目主入口,初始化并启动所有组件。
"""
import asyncio
import signal
import yaml
from workflow.engine import WorkflowEngine
from virtualization.docker_env import DockerVirtualizationEnv
from scheduler.dynamic_scheduler import DynamicResourceScheduler
from monitor.metrics import start_monitoring_server
import threading

def load_config():
    with open('config.yaml', 'r') as f:
        return yaml.safe_load(f)

async def main():
    config = load_config()
    print("Starting Agent Virtualization Tuning Demo...")

    # 1. 启动监控服务器(在独立线程中)
    threading.Thread(target=start_monitoring_server, daemon=True).start()

    # 2. 初始化虚拟化环境
    virt_env = DockerVirtualizationEnv(config['virtualization'])

    # 3. 初始化工作流引擎
    engine = WorkflowEngine(virt_env, config['workflow']['max_queue_size'])

    # 4. 初始化动态调度器
    scheduler = DynamicResourceScheduler(virt_env, engine, config)

    # 5. 创建后台任务
    engine_task = asyncio.create_task(engine.run())
    scheduler_task = asyncio.create_task(scheduler.run_scheduling_loop())

    # 6. 优雅停机处理
    loop = asyncio.get_running_loop()
    stop_event = asyncio.Event()
    for sig in (signal.SIGINT, signal.SIGTERM):
        loop.add_signal_handler(sig, stop_event.set)

    print("System is running. Press Ctrl+C to stop.")
    print(f"  - Workflow Engine: Active")
    print(f"  - Dynamic Scheduler: Active (strategy: {config['scheduler']['strategy']})")
    print(f"  - Metrics: http://localhost:{config['monitoring']['prometheus_port']}/metrics")
    print("\nYou can now run `python run_workload.py` to generate workload.")

    await stop_event.wait()
    print("\nShutting down...")

    # 7. 清理
    scheduler.stop()
    scheduler_task.cancel()
    engine_task.cancel()
    await asyncio.gather(scheduler_task, engine_task, return_exceptions=True)

    # 停止所有执行单元
    units = await virt_env.list_units()
    stop_tasks = [unit.stop() for unit in units.values()]
    await asyncio.gather(*stop_tasks, return_exceptions=True)

    print("Shutdown complete.")

if __name__ == "__main__":
    asyncio.run(main())

文件路径: run_workload.py

"""
生成模拟工作流负载的脚本。
"""
import asyncio
import random
import sys
import uuid
from main import load_config, WorkflowEngine, DockerVirtualizationEnv

async def submit_random_workflow(engine: WorkflowEngine):
    """提交一个随机步骤的工作流"""
    steps = []
    skills = ["text_processor", "ai_inference", "data_aggregator"]
    num_steps = random.randint(2, 4)
    for i in range(num_steps):
        skill = random.choice(skills)
        input_data = f"Payload-{uuid.uuid4().hex[:6]} for step {i+1}"
        steps.append({"skill": skill, "input": input_data})
    try:
        wf_id = await engine.submit_workflow(steps)
        print(f"  Submitted workflow {wf_id} with {num_steps} steps.")
        return True
    except Exception as e:
        print(f"  Failed to submit workflow: {e}")
        return False

async def continuous_workload(duration_seconds: int = 60, request_per_second: float = 2.0):
    """持续生成负载"""
    config = load_config()
    virt_env = DockerVirtualizationEnv(config['virtualization'])
    engine = WorkflowEngine(virt_env, config['workflow']['max_queue_size'])

    # 启动引擎处理循环(独立任务)
    engine_task = asyncio.create_task(engine.run())

    interval = 1.0 / request_per_second
    end_time = asyncio.get_event_loop().time() + duration_seconds

    print(f"Starting workload for {duration_seconds} seconds at {request_per_second} req/s...")
    count = 0
    while asyncio.get_event_loop().time() < end_time:
        start = asyncio.get_event_loop().time()
        success = await submit_random_workflow(engine)
        if success:
            count += 1
        elapsed = asyncio.get_event_loop().time() - start
        await asyncio.sleep(max(0, interval - elapsed))

    print(f"Workload finished. Submitted {count} workflows.")
    engine_task.cancel()
    try:
        await engine_task
    except asyncio.CancelledError:
        pass

    # 简单清理
    units = await virt_env.list_units()
    for unit in units.values():
        await unit.stop()

if __name__ == "__main__":
    if len(sys.argv) > 1:
        duration = int(sys.argv[1])
    else:
        duration = 60
    if len(sys.argv) > 2:
        rps = float(sys.argv[2])
    else:
        rps = 2.0
    asyncio.run(continuous_workload(duration, rps))

文件路径: tests/test_workflow.py

"""
工作流引擎单元测试。
"""
import pytest
import asyncio
from unittest.mock import AsyncMock, MagicMock
from workflow.engine import WorkflowEngine, WorkflowStep
from virtualization.base import VirtualizationEnv, ExecutionUnit, ResourceSpec

@pytest.mark.asyncio
async def test_workflow_submission():
    """测试工作流提交"""
    mock_env = MagicMock(spec=VirtualizationEnv)
    mock_env.create_unit = AsyncMock()
    mock_unit = MagicMock(spec=ExecutionUnit)
    mock_unit.unit_id = "test-unit"
    mock_unit.resource_spec = ResourceSpec(1.0, 512)
    mock_unit.status = "running"
    mock_unit.start = AsyncMock()
    mock_unit.execute = AsyncMock(return_value={"success": True, "output": "test output", "execution_time_ms": 50})
    mock_env.create_unit.return_value = mock_unit

    engine = WorkflowEngine(mock_env, max_queue_size=10)

    steps_def = [{"skill": "text_processor", "input": "Hello"}]
    wf_id = await engine.submit_workflow(steps_def)

    assert wf_id.startswith("wf-")
    assert engine.pending_queue.qsize() == 1
    # 注意:由于引擎处理是异步的,这里可能需要等待或直接测试提交逻辑

@pytest.mark.asyncio
async def test_skill_execution():
    """测试技能执行"""
    from workflow.skills import SKILL_REGISTRY
    # 确保技能存在
    assert "text_processor" in SKILL_REGISTRY
    skill = SKILL_REGISTRY["text_processor"]
    assert skill.name == "text_processor"
    assert "python -c" in skill.command

4. 安装依赖与运行步骤

4.1 前置条件

  • 系统: Linux, macOS 或 WSL2 (Windows Subsystem for Linux 2)。
  • Docker: 确保Docker守护进程已安装并正在运行。运行 docker --version 确认。
  • Python: Python 3.9 或更高版本。

4.2 安装步骤

  1. 克隆/创建项目目录:
mkdir agent-virt-tuning && cd agent-virt-tuning
  1. 将上述所有代码文件按照"项目结构树"放置到对应目录
  2. 安装Python依赖:
pip install -r requirements.txt

4.3 运行系统

  1. 启动主系统 (在一个终端中):
python main.py
系统将启动,并显示监控地址。此时工作流引擎和调度器已就绪,但还没有负载。
  1. 生成模拟负载 (在另一个终端中):
# 默认运行60秒,每秒2个请求
    python run_workload.py
    # 自定义运行120秒,每秒5个请求
    # python run_workload.py 120 5
观察第一个终端中的日志,你会看到工作流被提交、执行,以及调度器动态调整资源的记录。
  1. 查看监控指标:
    打开浏览器,访问 http://localhost:8000/metrics,你将看到Prometheus格式的指标数据。

4.4 (可选) 使用Grafana可视化

  1. 安装并运行Grafana (参考官方文档)。
  2. 将Prometheus (http://localhost:8000) 添加为数据源。
  3. 导入仪表板,使用类似以下的PromQL查询创建图表:
    • 平均延迟: rate(workflow_latency_seconds_sum{strategy="balanced"}[5m]) / rate(workflow_latency_seconds_count{strategy="balanced"}[5m])
    • 吞吐率: rate(workflow_throughput_total{strategy="balanced"}[5m])
    • CPU分配: execution_unit_resource{resource_type="cpu"}

5. 测试与验证步骤

5.1 运行单元测试

pytest tests/ -v

这将运行 test_workflow.py 中的测试用例,验证工作流提交和技能注册的基本功能。

5.2 手动接口验证

系统运行后,你可以编写一个简单的脚本进行快速验证:

# quick_test.py
import asyncio
import sys
sys.path.insert(0, '.')
from main import load_config, WorkflowEngine, DockerVirtualizationEnv

async def test():
    config = load_config()
    virt_env = DockerVirtualizationEnv(config['virtualization'])
    engine = WorkflowEngine(virt_env, 10)
    # 启动引擎
    engine_task = asyncio.create_task(engine.run())
    # 提交一个简单工作流
    steps = [{"skill": "text_processor", "input": "Quick Test Input"}]
    wf_id = await engine.submit_workflow(steps)
    print(f"Submitted: {wf_id}")
    # 等待几秒让任务处理
    await asyncio.sleep(3)
    # 检查实例状态(简化,实际应从引擎获取)
    print("Test completed. Check main console for execution logs.")
    engine_task.cancel()
    await engine_task

if __name__ == "__main__":
    asyncio.run(test())

运行: python quick_test.py

6. 性能调优实践与扩展

6.1 调优策略实验

修改 config.yaml 中的 scheduler.strategylatency_firstthroughput_first,重新运行系统并施加负载。观察不同策略下:

  • 工作流的完成延迟 (workflow_latency_seconds)
  • 系统整体吞吐 (workflow_throughput_total)
  • 执行单元的平均资源使用率 (execution_unit_resource)

你将看到latency_first策略倾向于分配更多资源,延迟较低但资源利用率可能下降;throughput_first策略则相反。

6.2 核心权衡关系可视化

graph LR A[严格资源限制] --> B[高资源利用率] A --> C[任务排队增加] C --> D[尾部延迟显著上升] B --> E[单位资源吞吐高] C --> F[整体吞吐可能受限] G[宽松资源限制] --> H[低资源利用率] G --> I[任务快速处理] I --> J[延迟降低] I --> K[整体吞吐潜力高] H --> L[单位资源吞吐低] M[动态调度目标] --> N[在SLO延迟约束内] N --> O[最大化整体吞吐] O --> P[提升资源利用率]

图1:延迟与吞吐的核心权衡关系。动态调度器的目标是在延迟SLO(红色虚线框)的约束下,寻找整体吞吐与资源利用率的最优平衡点。

6.3 智能体工作流执行序列图

sequenceDiagram participant Client participant Engine participant Scheduler participant Env(Docker Env) participant Unit1 as Unit: Skill A participant Unit2 as Unit: Skill B Note over Client,Unit2: 工作流提交与执行阶段 Client->>Engine: submit_workflow([A, B]) Engine->>Engine: 实例入队 Engine->>Env: create/acquire Unit for Skill A Env-->>Engine: Unit1 Engine->>Unit1: execute(Skill A command) Unit1-->>Engine: Result A Engine->>Env: create/acquire Unit for Skill B Env-->>Engine: Unit2 Engine->>Unit2: execute(Skill B command) Unit2-->>Engine: Result B Engine-->>Client: (异步) Workflow Completed Note over Scheduler,Unit2: 动态调度阶段(周期性) loop Every N seconds Scheduler->>Engine: collect metrics (latency, queue) Scheduler->>Env: collect unit resources Scheduler->>Scheduler: analyze & make decision Scheduler->>Unit1: update_resources(new_spec) Scheduler->>Unit2: update_resources(new_spec) end

图2:智能体工作流执行与动态资源调度序列。展示了从工作流提交到步骤在独立容器单元中执行,以及后台调度器周期性收集指标并调整资源限额的完整流程。

6.4 扩展方向

  1. 更真实的技能:将技能命令替换为调用真实的机器学习模型API(如加载TensorFlow模型)、数据库查询或外部工具。
  2. 高级调度算法:实现基于强化学习(RL)的调度器,根据历史指标预测未来负载并提前调整资源。
  3. 多级虚拟化:支持 gVisorKata Containers 作为执行环境,比较其安全开销对性能的影响。
  4. Kubernetes集成:将 ExecutionUnit 实现为Kubernetes Pod,利用K8s的Horizontal Pod Autoscaler (HPA) 和 Vertical Pod Autoscaler (VPA) 进行伸缩,与本项目的调度器进行对比。
  5. 混沌工程测试:在系统中注入网络延迟、模拟容器故障,测试调度器的容错与恢复能力。

通过本项目,你不仅获得了一个可运行的研究原型,更得到了一个可以深入探索虚拟化智能体系统性能调优的实验平台。核心在于理解监控数据、做出决策并验证效果这一闭环,这是云原生智能体系统运维的关键能力。