Files
AgentLab/backend/app/engine/nodes/multi.py
T
ThearchyHelios c3f7d6ffcd 协作团队真的能并行了,界面上也看得出来
先说一个和名字不符的事实:这个节点叫「多 Agent 协作」,但在此之前它是一条
严格的串行流水线。调度协议写死成 `next: string`——"一次只能派一个"被编进了
协议本身,模型再想并行也表达不出来。三个专家各花 10 秒,总是 30 秒。

(真并行一直在图级 fan-out:实测 3 个各 sleep 2 秒的节点连在同一个上游,
全部 +0.00s 开始、+2.37s 结束,墙钟 2.6 秒。只是协作团队走不到那条路。)

**协议改成 assignments 数组**,一轮可以派多个互不依赖的专家,asyncio.gather
并发执行,总耗时按最慢的那个算。max_parallel 可配,设成 1 即退回严格串行。

**并发只在任务真的互不依赖时才成立**,这件事的成本必须说清楚:同一轮发出去的
专家拿到的是**同一份进展快照**,谁也看不见谁这一轮干了什么。派错了不报错,
只会让两个人基于一样的旧信息重复劳动,而这在结果里很难看出来。所以判断责任
压在调度者身上,提示词里把反例写出来:

    可以同时派:「查 A 的资料」和「查 B 的资料」
    不能同时派:「查资料」和「根据资料写报告」
    不能同时派:「写初稿」和「校对初稿」

并明确告诉它拿不准就分两轮——代价只是慢一点。

**每个人单独计时**,而不是事后拿整轮墙钟去摊。界面要显示"并行省下多少",
那个数必须是量出来的:按 N×墙钟 推算等于假设每个人都跑满了最慢那条,
而实际上快的那个可能只花了三分之一。测试里专门有个快慢不对称的用例守这条。

**调度日志改成结构化字段**(agents / done / reason / parallel)。以前只有一句
中文消息串,解码层得拿正则去拆「调度 → X(理由)」——后端文案一改就散架,
而这次正是改了文案。老运行的事件没有这些字段,正则那条路留着兜底。

**界面加泳道。** 每个成员一行、每轮一格,条形宽度按耗时归一化,所以一眼看得出
谁和谁是同时干的、谁是这一轮的瓶颈。顶上一行汇总"3 名成员 · 3 轮 · 2 轮并行,
省下 11.8s";点任意一格展开那个人这一轮的任务和回复。全程串行时不装作有并行,
而是说"本次任务互相依赖,逐轮进行"。

泳道排在子步骤**前面**:先给一眼看清的形状,再往下是每一步的内容。反过来的话,
得把十几行步骤读完才知道这个团队是怎么分工的。窄栏(画布右栏 360px)下隐去
"N 人同时"的文字——并行与否看条形本来就一目了然,而缩写成"并2"没人看得懂。

验证:后端 276 passed(新增 test_supervisor.py 7 条,核心那条用**墙钟**判定
并发而不是看事件顺序——顺序只能说明"发出去了",说明不了"同时跑");
check-stream 新增 10 条泳道断言,含"同一轮里慢的那个条更长"和两种栏宽不溢出;
tsc 干净,三个 check 不回归。
2026-09-20 20:57:03 +08:00

428 lines
19 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
from __future__ import annotations
import asyncio
import json
import time
from typing import Any
from langchain_core.messages import AIMessage, HumanMessage, SystemMessage, ToolMessage
from langgraph.func import task
from app.core.config import settings
from app.core.events import EventType
from app.db.base import SessionLocal
from app.db.models import Workflow
from app.engine.context import NodeContext, NodeError
from app.engine.state import GraphState, message_text, template_context
from app.providers import catalog
from app.providers.factory import ModelSpec, bind_tools_safely, get_chat_model
from app.tools.registry import (
ToolArgsError,
ToolContext,
args_model_of,
build_tools,
prepare_args,
)
_MAX_DEPTH = 3
# --------------------------------------------------------------------------
# Supervisor:一个调度者 + 若干专家
# --------------------------------------------------------------------------
async def run_supervisor(state: GraphState, ctx: NodeContext) -> dict[str, Any]:
"""多 agent 协作。
调度者每轮只做一件事:看当前进展,决定交给哪个专家、并给它一句具体指令,
或者宣布收工。专家各自带自己的 system prompt 和工具集。
把整个协作塞进一个节点,是为了让画布保持可读 —— 展开细节看运行时间线就够了。
"""
agents = ctx.cfg("agents", []) or []
if not agents:
raise NodeError(ctx.node.id, "supervisor 节点至少要配一个 agent")
names = [a.get("name") or f"agent{i}" for i, a in enumerate(agents)]
agent_map = {n: a for n, a in zip(names, agents)}
max_rounds = min(int(ctx.cfg("max_rounds", 6) or 6), settings.max_agent_steps)
goal = ctx.render_str(ctx.cfg("goal", "{{ last_message }}"), state)
if not goal.strip():
goal = json.dumps(template_context(state).get("input"), ensure_ascii=False)
async with SessionLocal() as session:
supervisor_model, sup_model_id = await get_chat_model(
session,
ModelSpec(
provider=ctx.cfg("provider"),
model=ctx.cfg("model"),
max_tokens=int(ctx.cfg("max_tokens", 2048) or 2048),
),
)
roster = "\n".join(
f"- {n}:{agent_map[n].get('description') or agent_map[n].get('system', '')[:100]}"
for n in names
)
# 一轮可以派给多个专家。协议用 assignments 数组而不是单个 next:
# 后者把"一次只能派一个"编进了协议本身,模型再想并行也表达不出来。
#
# 但并行只在任务**互不依赖**时才成立——并发的几个专家看到的是同一份进展
# 快照,谁也看不见谁。派错了不会报错,只会让两个人基于同样的旧信息
# 重复劳动,而这件事在结果里很难看出来。所以判断责任明确压在调度者身上,
# 提示词里把反例写出来。
route_schema = {
"title": "route", # langchain 靠 title 识别 JSON Schema dict
"type": "object",
"properties": {
"assignments": {
"type": "array",
"description": "这一轮要派出去的任务。互不依赖时可以给多个,它们会同时执行",
"items": {
"type": "object",
"properties": {
"agent": {"type": "string", "enum": names},
"instruction": {"type": "string"},
},
"required": ["agent", "instruction"],
},
},
"done": {"type": "boolean", "description": "目标已达成,结束协作"},
"reason": {"type": "string"},
},
"required": ["assignments"],
}
#: 一轮最多同时派几个。再多的话调度者多半只是在把任务拆碎,
#: 而每多一路就多一份"基于陈旧进展"的风险
max_parallel = max(1, min(int(ctx.cfg("max_parallel", 3) or 3), len(names)))
transcript: list[dict[str, Any]] = []
usage_total = {"input_tokens": 0, "output_tokens": 0, "cost_usd": 0.0, "calls": 0}
def _accumulate(msg: Any, model_id: str) -> None:
meta = getattr(msg, "usage_metadata", None) or {}
i, o = int(meta.get("input_tokens") or 0), int(meta.get("output_tokens") or 0)
usage_total["input_tokens"] += i
usage_total["output_tokens"] += o
usage_total["calls"] += 1
usage_total["cost_usd"] = round(
usage_total["cost_usd"] + catalog.estimate_cost(model_id, i, o), 6
)
@task
async def route(round_no: int, progress: str) -> dict[str, Any]:
prompt = (
f"你是团队调度者。目标:\n{goal}\n\n"
f"可用成员:\n{roster}\n\n"
f"当前进展:\n{progress or '(还没有任何进展)'}\n\n"
"决定这一轮把什么任务交给谁,每个任务给一句明确的指令。\n\n"
f"**互不依赖的任务可以放在同一轮**(最多 {max_parallel} 个),它们会同时执行,"
"总耗时按最慢的那个算。判断依据只有一条:**后一个任务需不需要看到前一个的结果**。\n"
" 可以同时派:「查 A 产品的资料」和「查 B 产品的资料」——两边互不相干\n"
" 不能同时派:「查资料」和「根据资料写报告」——后者要等前者\n"
" 不能同时派:「写初稿」和「校对初稿」——同上\n\n"
"同时派出去的成员看到的是**同一份进展快照**,谁也看不见谁这一轮干了什么。"
"拿不准是否独立时就分两轮派,代价只是慢一点;派错了则是两个人基于同样的"
"旧信息重复劳动,而这在结果里很难看出来。\n\n"
"目标已经达成时,done 填 true、assignments 给空数组。"
)
try:
value = await supervisor_model.with_structured_output(route_schema).ainvoke(prompt)
if not isinstance(value, dict):
value = json.loads(message_text(value))
except Exception: # noqa: BLE001
# 不支持结构化输出的模型退回文本:从回复里认出一个成员名,按单人派
raw = message_text(await supervisor_model.ainvoke(prompt))
picked = next((n for n in names if n in raw), None)
value = ({"assignments": [{"agent": picked, "instruction": raw[:500]}]}
if picked else {"assignments": [], "done": True, "reason": raw[:200]})
return value
@task
async def work(round_no: int, name: str, instruction: str, progress: str) -> dict[str, Any]:
cfg = agent_map[name]
async with SessionLocal() as session:
model, model_id = await get_chat_model(
session,
ModelSpec(
provider=cfg.get("provider") or ctx.cfg("provider"),
model=cfg.get("model") or ctx.cfg("model"),
max_tokens=int(cfg.get("max_tokens") or 4096),
),
)
tool_ctx = ToolContext(
run_id=ctx.run.run_id,
node_id=f"{ctx.node.id}:{name}",
sandbox_session=ctx.run.thread_id,
memory_scope=ctx.run.memory_scope,
collection=ctx.run.collection,
)
tools = await build_tools(cfg.get("tools", []) or [], tool_ctx, session=session)
bound = bind_tools_safely(model, tools, parallel=False)
tool_map = {t.name: t for t in tools}
messages: list[Any] = [
SystemMessage(content=cfg.get("system") or f"你是 {name}。"),
HumanMessage(content=f"团队目标:{goal}\n\n已有进展:\n{progress or '(无)'}\n\n你的任务:{instruction}"),
]
calls: list[dict[str, Any]] = []
for _ in range(int(cfg.get("max_steps") or 4)):
reply = await bound.ainvoke(messages)
_accumulate(reply, model_id)
messages.append(reply)
tool_calls = getattr(reply, "tool_calls", None) or []
if not tool_calls:
return {"text": message_text(reply), "tool_calls": calls}
for call in tool_calls:
tname = call.get("name", "")
targs = call.get("args", {}) or {}
cid = call.get("id") or f"{name}-{tname}"
if tname not in tool_map:
ctx.emit(EventType.TOOL_START, tool=tname, args=targs, agent=name, call_id=cid)
content = f"错误:没有名为 {tname} 的工具"
else:
schema = args_model_of(tool_map[tname])
fix_note = None
args_error = None
if schema is not None:
try:
targs, fix_note = prepare_args(schema, targs)
except ToolArgsError as e:
args_error = str(e)
# 纠正后的参数才是真正要执行的那份,tool.start 要发它
ctx.emit(EventType.TOOL_START, tool=tname, args=targs, agent=name, call_id=cid)
if fix_note:
ctx.emit(EventType.LOG, level="warn",
message=f"工具 {tname}:{fix_note}", code="tool_args_fixed")
if args_error:
# 参数就不对,没必要真调一次。把"它接受什么"喂回去让它改
content = args_error
else:
try:
raw = await tool_map[tname].ainvoke(targs)
content = raw if isinstance(raw, str) else json.dumps(raw, ensure_ascii=False, default=str)
except Exception as e: # noqa: BLE001
content = f"工具失败:{type(e).__name__}: {e}"
ctx.emit(EventType.TOOL_END, tool=tname, agent=name, call_id=cid, preview=content[:1500])
calls.append({"tool": tname, "args": targs, "result": content[:2000]})
messages.append(ToolMessage(content=content, tool_call_id=cid))
return {"text": message_text(messages[-1]), "tool_calls": calls}
progress_lines: list[str] = []
final_text = ""
rounds_meta: list[dict[str, Any]] = []
for round_no in range(max_rounds):
progress = "\n\n".join(progress_lines)
decision = await route(round_no, progress)
_accumulate(AIMessage(content=""), sup_model_id) # route 用了一次调用
reason = str(decision.get("reason", ""))
# 只留认得出的成员,并按上限截断。模型偶尔会重复派同一个人或者编一个
# 不存在的名字——这两种在并发里都是纯浪费
batch: list[tuple[str, str]] = []
seen: set[str] = set()
for item in decision.get("assignments") or []:
name = str((item or {}).get("agent") or "")
if name in agent_map and name not in seen:
seen.add(name)
batch.append((name, str(item.get("instruction") or goal)))
if len(batch) >= max_parallel:
break
if decision.get("done") or not batch:
# agents / done 是结构化字段,界面照着它渲染。以前只有一句中文
# 消息串,解码层得拿正则去拆「调度 → X(理由)」——文案一改就散架
ctx.emit(EventType.LOG, level="info", round=round_no,
agents=[], done=True,
message="调度 → 结束协作" + (f"({reason})" if reason else ""))
final_text = progress_lines[-1].split("】", 1)[-1] if progress_lines else ""
break
who = "、".join(n for n, _ in batch)
ctx.emit(
EventType.LOG, level="info", round=round_no, parallel=len(batch),
agents=[n for n, _ in batch], done=False, reason=reason,
message=(f"调度 → {who}" + (f"({reason})" if reason else "")
+ (f" · {len(batch)} 人同时进行" if len(batch) > 1 else "")),
)
for name, instruction in batch:
ctx.emit(EventType.AGENT_STEP_START, agent=name, instruction=instruction[:300],
round=round_no, parallel=len(batch))
# 并发执行。它们拿到的是**同一份** progress 快照——这正是"任务必须
# 互不依赖"的技术含义,也是上面提示词里那几条反例的由来。
#
# 每个人单独计时,而不是事后拿整轮墙钟去摊:界面要显示"并行省了多少
# 时间",那个数必须是量出来的。按 N×墙钟 推算等于假设每个人都跑满了
# 最慢那条,而实际上快的那个可能只花了三分之一
async def _timed(name: str, instruction: str) -> tuple[str, Any, int]:
t0 = time.perf_counter()
try:
out: Any = await work(round_no, name, instruction, progress)
except BaseException as exc: # noqa: BLE001 - 交给下面统一处置
out = exc
return name, out, int((time.perf_counter() - t0) * 1000)
started = time.perf_counter()
results = await asyncio.gather(*(_timed(n, i) for n, i in batch))
wall_ms = int((time.perf_counter() - started) * 1000)
sum_ms = 0
for (name, instruction), (_, outcome, each_ms) in zip(batch, results):
if isinstance(outcome, BaseException):
# 一个专家挂了不该拖垮整轮:把失败当成它的产出交回调度者,
# 让它决定改派还是收工
text = f"({name} 执行失败:{type(outcome).__name__}: {outcome})"
outcome = {"text": text, "tool_calls": []}
ctx.emit(EventType.LOG, level="warn", round=round_no,
message=f"{name} 这一轮失败了:{text}")
sum_ms += each_ms
ctx.emit(EventType.AGENT_STEP_END, agent=name, duration_ms=each_ms,
round=round_no, parallel=len(batch), preview=outcome["text"][:500])
progress_lines.append(f"【{name}】{outcome['text']}")
transcript.append(
{"round": round_no, "agent": name, "instruction": instruction, **outcome,
"duration_ms": each_ms}
)
final_text = outcome["text"]
rounds_meta.append({
"round": round_no, "agents": [n for n, _ in batch],
"parallel": len(batch), "wall_ms": wall_ms, "sum_ms": sum_ms,
})
usage_total["total_tokens"] = usage_total["input_tokens"] + usage_total["output_tokens"]
# 并行省下的时间:各轮"串行本该花的"减去"实际花的"。只有并发过才有差值
saved_ms = sum(r["sum_ms"] - r["wall_ms"] for r in rounds_meta)
result = {
"text": final_text,
"rounds": len(rounds_meta),
"steps": len(transcript),
"transcript": transcript,
"agents": names,
"schedule": rounds_meta,
"parallel_saved_ms": saved_ms,
}
updates: dict[str, Any] = {
"nodes": {ctx.node.id: result},
"usage": usage_total,
}
if ctx.cfg("emit_message", True):
updates["messages"] = [AIMessage(content=final_text or "(空)")]
var_name = ctx.cfg("assign_to", "")
if var_name:
updates["vars"] = {var_name: final_text}
return updates
# --------------------------------------------------------------------------
# 子图:把另一张工作流当成一个节点
# --------------------------------------------------------------------------
async def run_subgraph(state: GraphState, ctx: NodeContext) -> dict[str, Any]:
"""嵌套执行另一个工作流。
子图共享同一个 run 的事件流(节点 id 会加前缀),所以在时间线上能看到它内部
每一步;但它有独立的状态,不会污染父图的变量池。
"""
from app.engine.compiler import compile_graph # 延迟导入,避免循环依赖
from app.engine.schema import GraphSpec
if ctx.run.depth >= _MAX_DEPTH:
raise NodeError(ctx.node.id, f"子图嵌套超过 {_MAX_DEPTH} 层,已阻止")
workflow_id = ctx.cfg("workflow_id")
if not workflow_id:
raise NodeError(ctx.node.id, "子图节点没有选择工作流")
# 版本钉死:这就是"方法卡"的机制核心。钉了 workflow_version 就永远
# 执行那个不可变快照,上游改了方法卡也不会让这里的口径悄悄漂移;
# 没钉则跟随最新(画布试跑方便,但治理 lint 会在受管模板里拦下它)。
pinned = ctx.cfg("workflow_version")
async with SessionLocal() as session:
workflow = await session.get(Workflow, workflow_id)
if not workflow:
raise NodeError(ctx.node.id, f"找不到工作流 {workflow_id}")
if pinned:
from sqlalchemy import select
from app.db.models import WorkflowVersion
snapshot = (
await session.execute(
select(WorkflowVersion).where(
WorkflowVersion.workflow_id == workflow_id,
WorkflowVersion.version == int(pinned),
)
)
).scalar_one_or_none()
if not snapshot:
raise NodeError(
ctx.node.id, f"工作流「{workflow.name}」没有 v{pinned} 这个版本"
)
sub_graph = snapshot.graph
used_version = int(pinned)
else:
sub_graph = workflow.graph
used_version = workflow.version
sub_input = ctx.render(ctx.cfg("input", {}) or {}, state)
if not isinstance(sub_input, dict):
sub_input = {"input": sub_input}
sub_spec = GraphSpec.model_validate(sub_graph)
sub_run = type(ctx.run)(
run_id=ctx.run.run_id,
thread_id=f"{ctx.run.thread_id}:{ctx.node.id}",
spec=sub_spec,
workflow_id=workflow.id,
depth=ctx.run.depth + 1,
memory_scope=ctx.run.memory_scope,
collection=ctx.run.collection,
extra={**ctx.run.extra, "node_prefix": f"{ctx.node.id}/"},
)
ctx.emit(EventType.LOG, level="info",
message=f"进入子图「{workflow.name}」({len(sub_spec.nodes)} 个节点)")
compiled = compile_graph(sub_spec, sub_run)
# 子图不带 checkpointer:它的断点由父图的 checkpoint 统一承载
app = compiled.compile()
result_state = await app.ainvoke(
{
"input": sub_input,
"vars": sub_input,
"nodes": {},
"output": {},
"messages": [],
"usage": {},
"trail": [],
"loops": {},
},
{"recursion_limit": settings.max_graph_steps},
)
output = result_state.get("output") or {}
result = {
"output": output,
"workflow": workflow.name,
# 溯源信息:这次到底跑的是哪个版本、是不是钉死的
"workflow_version": used_version,
"pinned": bool(pinned),
"text": json.dumps(output, ensure_ascii=False) if output else "",
}
ctx.emit(EventType.LOG, level="info", message=f"子图「{workflow.name}」完成")
updates: dict[str, Any] = {
"nodes": {ctx.node.id: result},
"usage": result_state.get("usage") or {},
}
var_name = ctx.cfg("assign_to", "")
if var_name:
updates["vars"] = {var_name: output}
return updates