takahe/stator/runner.py

105 lines
3.9 KiB
Python

import asyncio
import datetime
import time
import traceback
import uuid
from typing import List, Optional, Type
from django.utils import timezone
from core import exceptions
from core.models import Config
from stator.models import StatorModel
class StatorRunner:
"""
Runs tasks on models that are looking for state changes.
Designed to run for a determinate amount of time, and then exit.
"""
def __init__(
self,
models: List[Type[StatorModel]],
concurrency: int = 50,
concurrency_per_model: int = 10,
liveness_file: Optional[str] = None,
schedule_interval: int = 30,
lock_expiry: int = 300,
):
self.models = models
self.runner_id = uuid.uuid4().hex
self.concurrency = concurrency
self.concurrency_per_model = concurrency_per_model
self.liveness_file = liveness_file
self.schedule_interval = schedule_interval
self.lock_expiry = lock_expiry
async def run(self):
self.handled = 0
self.last_clean = time.monotonic() - self.schedule_interval
self.tasks = []
# For the first time period, launch tasks
print("Running main task loop")
try:
while True:
# Do we need to do cleaning?
if (time.monotonic() - self.last_clean) >= self.schedule_interval:
# Refresh the config
Config.system = await Config.aload_system()
print(f"{self.handled} tasks processed so far")
print("Running cleaning and scheduling")
for model in self.models:
asyncio.create_task(model.atransition_clean_locks())
asyncio.create_task(model.atransition_schedule_due())
self.last_clean = time.monotonic()
# Calculate space left for tasks
self.remove_completed_tasks()
space_remaining = self.concurrency - len(self.tasks)
# Fetch new tasks
for model in self.models:
if space_remaining > 0:
for instance in await model.atransition_get_with_lock(
number=min(space_remaining, self.concurrency_per_model),
lock_expiry=(
timezone.now()
+ datetime.timedelta(seconds=self.lock_expiry)
),
):
self.tasks.append(
asyncio.create_task(self.run_transition(instance))
)
self.handled += 1
space_remaining -= 1
# Prevent busylooping
await asyncio.sleep(0.1)
except KeyboardInterrupt:
# Wait for tasks to finish
print("Waiting for tasks to complete")
while True:
self.remove_completed_tasks()
if not self.tasks:
break
# Prevent busylooping
await asyncio.sleep(1)
print("Complete")
return self.handled
async def run_transition(self, instance: StatorModel):
"""
Wrapper for atransition_attempt with fallback error handling
"""
try:
print(
f"Attempting transition on {instance._meta.label_lower}#{instance.pk} from state {instance.state}"
)
await instance.atransition_attempt()
except BaseException as e:
await exceptions.acapture_exception(e)
traceback.print_exc()
def remove_completed_tasks(self):
"""
Removes all completed asyncio.Tasks from our local in-progress list
"""
self.tasks = [t for t in self.tasks if not t.done()]