portfolio-optimiser/spikes/b_footguns.py

122 lines
5.3 KiB
Python

"""Spike B — Magentic unbounded-termination footgun (G1/B4) + fan-out state
isolation (G2/B7).
Driving the GA builders with the fake client (de-risked by the Step 2 smoke) *is*
the experiment here — no live LLM, so this whole spike runs in the quality gate.
(a) **Magentic unbounded (G1/B4).** A `StandardMagenticManager` whose progress ledger
always says "not satisfied / progress being made" never finalizes. With
`max_round_count=None` it would loop forever; we drive it under the shared harness
round/iteration guard and confirm the guard is what stops it (it does NOT
self-terminate). With an explicit `max_round_count` it terminates cleanly.
(b) **Fan-out state isolation (G2/B7).** Reusing ONE workflow instance across the three
reference projects bleeds state (the shared fake clients accumulate calls); a FRESH
instance per run — via `fresh_workflow()` — shows zero bleed.
Token use: 0 — no live LLM (the fake client's "tokens" are word-counts of canned replies).
"""
from __future__ import annotations
import json
import logging
import warnings
from agent_framework import Agent
from agent_framework.orchestrations import (
ConcurrentBuilder,
MagenticBuilder,
StandardMagenticManager,
)
from spikes._harness import Budget, BudgetExceeded, FakeChatClient, TokenMeter, fake_agent
# Cutting an *instrumented* Magentic stream short (the only way to observe an unbounded
# run) makes OpenTelemetry log a benign "Failed to detach context" on generator close.
# It is cosmetic — silence it so the spike output stays readable. (Recorded in findings-b.)
logging.getLogger("opentelemetry.context").setLevel(logging.CRITICAL)
# A progress ledger that never reports satisfaction and always claims progress — so the
# manager has no natural reason to stop. next_speaker points at the single worker.
_NEVER_SATISFIED_LEDGER = json.dumps(
{
"is_request_satisfied": {"reason": "not yet", "answer": False},
"is_in_loop": {"reason": "no", "answer": False},
"is_progress_being_made": {"reason": "yes", "answer": True},
"next_speaker": {"reason": "worker should act", "answer": "worker"},
"instruction_or_question": {"reason": "continue", "answer": "Keep working."},
}
)
def _magentic(max_round_count: int | None) -> object:
"""Build a Magentic workflow whose manager never self-finalizes."""
manager = StandardMagenticManager(
agent=Agent(
FakeChatClient(default_reply=_NEVER_SATISFIED_LEDGER), "manager", name="manager"
),
max_round_count=max_round_count,
)
worker = Agent(FakeChatClient(default_reply="worker did some work"), "worker", name="worker")
return MagenticBuilder(participants=[worker], manager=manager).build()
async def unbounded_magentic_self_terminates(*, guard_rounds: int = 10) -> bool:
"""Drive an unbounded (`max_round_count=None`) Magentic under the harness guard.
Returns ``True`` if the workflow stopped on its own, ``False`` if the external guard
had to stop it. The footgun (G1/B4) is confirmed when this returns ``False``.
"""
workflow = _magentic(None)
meter = TokenMeter(Budget(max_tokens=10**9, max_rounds=guard_rounds))
guard_fired = False
with warnings.catch_warnings():
warnings.simplefilter("ignore", RuntimeWarning)
async for _event in workflow.run("Do a never-ending task.", stream=True):
try:
meter.tick_round() # one tick per orchestration event (iteration guard)
except BudgetExceeded:
guard_fired = True
break
return not guard_fired
async def bounded_magentic_terminates(*, max_round_count: int = 2) -> bool:
"""An explicit `max_round_count` makes the same never-satisfied manager stop cleanly.
Returns ``True`` when the workflow runs to completion and yields an output.
"""
workflow = _magentic(max_round_count)
result = await workflow.run("Do a bounded task.")
return len(result.get_outputs()) >= 1
def fresh_workflow() -> tuple[object, tuple[FakeChatClient, FakeChatClient]]:
"""B7 mitigation: a factory that builds a FRESH fan-out workflow with FRESH clients
every call, so no state survives between runs."""
c1 = FakeChatClient(default_reply="participant one view")
c2 = FakeChatClient(default_reply="participant two view")
workflow = ConcurrentBuilder(participants=[fake_agent(c1, "w1"), fake_agent(c2, "w2")]).build()
return workflow, (c1, c2)
async def shared_instance_max_calls(project_ids: list[str]) -> int:
"""Reuse ONE fan-out instance across every project — state bleeds: the shared clients
accumulate calls across runs. Returns the max per-client call count (== len once
bled)."""
workflow, clients = fresh_workflow()
for pid in project_ids:
await workflow.run(f"Evaluate project {pid}.")
return max(c.call_count for c in clients)
async def fresh_instance_call_counts(project_ids: list[str]) -> list[int]:
"""A FRESH instance per project — zero bleed: every run's clients see exactly one
call. Returns the per-run max call count (each should be 1)."""
counts: list[int] = []
for pid in project_ids:
workflow, clients = fresh_workflow()
await workflow.run(f"Evaluate project {pid}.")
counts.append(max(c.call_count for c in clients))
return counts