Purpose

The /abort_requests endpoint (disaggregated api_router.py) schedules the abort with a bare asyncio.create_task(...) and discards the returned task:

# Abort requests in background
asyncio.create_task(engine_client(raw_request).abort(request_ids))
return Response(status_code=200)

Per the asyncio docs, the event loop only keeps a weak reference to a task. A task with no other reference can be garbage-collected before it finishes. Here that means the abort coroutine can be collected mid-run, so under load the requested aborts may silently not happen — the endpoint returns 200 either way, so the failure is invisible.

Fix

Keep a strong reference to the task in a module-level set and remove it on completion via add_done_callback (the pattern recommended in the asyncio docs):

task = asyncio.create_task(engine_client(raw_request).abort(request_ids))
_background_tasks.add(task)
task.add_done_callback(_background_tasks.discard)

No behavior change beyond guaranteeing the abort task actually runs to completion. Single file, +9/-2.

Test Plan

• python -m py_compile clean.
• No functional change to the endpoint's contract; the task is simply retained until it finishes rather than being eligible for GC.