mirror of
https://mau.dev/maunium/synapse.git
synced 2024-08-24 11:16:04 +00:00
![Eric Eastwood](/assets/img/avatar_default.png)
- Update black version to the latest
- Run black auto formatting over the codebase
- Run autoformatting according to [`docs/code_style.md
`](80d6dc9783/docs/code_style.md
)
- Update `code_style.md` docs around installing black to use the correct version
313 lines
11 KiB
Python
313 lines
11 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2015, 2016 OpenMarket Ltd
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
"""
|
|
This module controls the reliability for application service transactions.
|
|
|
|
The nominal flow through this module looks like:
|
|
__________
|
|
1---ASa[e]-->| Service |--> Queue ASa[f]
|
|
2----ASb[e]->| Queuer |
|
|
3--ASa[f]--->|__________|-----------+ ASa[e], ASb[e]
|
|
V
|
|
-````````- +------------+
|
|
|````````|<--StoreTxn-|Transaction |
|
|
|Database| | Controller |---> SEND TO AS
|
|
`--------` +------------+
|
|
What happens on SEND TO AS depends on the state of the Application Service:
|
|
- If the AS is marked as DOWN, do nothing.
|
|
- If the AS is marked as UP, send the transaction.
|
|
* SUCCESS : Increment where the AS is up to txn-wise and nuke the txn
|
|
contents from the db.
|
|
* FAILURE : Marked AS as DOWN and start Recoverer.
|
|
|
|
Recoverer attempts to recover ASes who have died. The flow for this looks like:
|
|
,--------------------- backoff++ --------------.
|
|
V |
|
|
START ---> Wait exp ------> Get oldest txn ID from ----> FAILURE
|
|
backoff DB and try to send it
|
|
^ |___________
|
|
Mark AS as | V
|
|
UP & quit +---------- YES SUCCESS
|
|
| | |
|
|
NO <--- Have more txns? <------ Mark txn success & nuke <-+
|
|
from db; incr AS pos.
|
|
Reset backoff.
|
|
|
|
This is all tied together by the AppServiceScheduler which DIs the required
|
|
components.
|
|
"""
|
|
import logging
|
|
from typing import List
|
|
|
|
from synapse.appservice import ApplicationService, ApplicationServiceState
|
|
from synapse.events import EventBase
|
|
from synapse.logging.context import run_in_background
|
|
from synapse.metrics.background_process_metrics import run_as_background_process
|
|
from synapse.types import JsonDict
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
# Maximum number of events to provide in an AS transaction.
|
|
MAX_PERSISTENT_EVENTS_PER_TRANSACTION = 100
|
|
|
|
# Maximum number of ephemeral events to provide in an AS transaction.
|
|
MAX_EPHEMERAL_EVENTS_PER_TRANSACTION = 100
|
|
|
|
|
|
class ApplicationServiceScheduler:
|
|
"""Public facing API for this module. Does the required DI to tie the
|
|
components together. This also serves as the "event_pool", which in this
|
|
case is a simple array.
|
|
"""
|
|
|
|
def __init__(self, hs):
|
|
self.clock = hs.get_clock()
|
|
self.store = hs.get_datastore()
|
|
self.as_api = hs.get_application_service_api()
|
|
|
|
self.txn_ctrl = _TransactionController(self.clock, self.store, self.as_api)
|
|
self.queuer = _ServiceQueuer(self.txn_ctrl, self.clock)
|
|
|
|
async def start(self):
|
|
logger.info("Starting appservice scheduler")
|
|
|
|
# check for any DOWN ASes and start recoverers for them.
|
|
services = await self.store.get_appservices_by_state(
|
|
ApplicationServiceState.DOWN
|
|
)
|
|
|
|
for service in services:
|
|
self.txn_ctrl.start_recoverer(service)
|
|
|
|
def submit_event_for_as(self, service: ApplicationService, event: EventBase):
|
|
self.queuer.enqueue_event(service, event)
|
|
|
|
def submit_ephemeral_events_for_as(
|
|
self, service: ApplicationService, events: List[JsonDict]
|
|
):
|
|
self.queuer.enqueue_ephemeral(service, events)
|
|
|
|
|
|
class _ServiceQueuer:
|
|
"""Queue of events waiting to be sent to appservices.
|
|
|
|
Groups events into transactions per-appservice, and sends them on to the
|
|
TransactionController. Makes sure that we only have one transaction in flight per
|
|
appservice at a given time.
|
|
"""
|
|
|
|
def __init__(self, txn_ctrl, clock):
|
|
self.queued_events = {} # dict of {service_id: [events]}
|
|
self.queued_ephemeral = {} # dict of {service_id: [events]}
|
|
|
|
# the appservices which currently have a transaction in flight
|
|
self.requests_in_flight = set()
|
|
self.txn_ctrl = txn_ctrl
|
|
self.clock = clock
|
|
|
|
def _start_background_request(self, service):
|
|
# start a sender for this appservice if we don't already have one
|
|
if service.id in self.requests_in_flight:
|
|
return
|
|
|
|
run_as_background_process(
|
|
"as-sender-%s" % (service.id,), self._send_request, service
|
|
)
|
|
|
|
def enqueue_event(self, service: ApplicationService, event: EventBase):
|
|
self.queued_events.setdefault(service.id, []).append(event)
|
|
self._start_background_request(service)
|
|
|
|
def enqueue_ephemeral(self, service: ApplicationService, events: List[JsonDict]):
|
|
self.queued_ephemeral.setdefault(service.id, []).extend(events)
|
|
self._start_background_request(service)
|
|
|
|
async def _send_request(self, service: ApplicationService):
|
|
# sanity-check: we shouldn't get here if this service already has a sender
|
|
# running.
|
|
assert service.id not in self.requests_in_flight
|
|
|
|
self.requests_in_flight.add(service.id)
|
|
try:
|
|
while True:
|
|
all_events = self.queued_events.get(service.id, [])
|
|
events = all_events[:MAX_PERSISTENT_EVENTS_PER_TRANSACTION]
|
|
del all_events[:MAX_PERSISTENT_EVENTS_PER_TRANSACTION]
|
|
|
|
all_events_ephemeral = self.queued_ephemeral.get(service.id, [])
|
|
ephemeral = all_events_ephemeral[:MAX_EPHEMERAL_EVENTS_PER_TRANSACTION]
|
|
del all_events_ephemeral[:MAX_EPHEMERAL_EVENTS_PER_TRANSACTION]
|
|
|
|
if not events and not ephemeral:
|
|
return
|
|
|
|
try:
|
|
await self.txn_ctrl.send(service, events, ephemeral)
|
|
except Exception:
|
|
logger.exception("AS request failed")
|
|
finally:
|
|
self.requests_in_flight.discard(service.id)
|
|
|
|
|
|
class _TransactionController:
|
|
"""Transaction manager.
|
|
|
|
Builds AppServiceTransactions and runs their lifecycle. Also starts a Recoverer
|
|
if a transaction fails.
|
|
|
|
(Note we have only have one of these in the homeserver.)
|
|
|
|
Args:
|
|
clock (synapse.util.Clock):
|
|
store (synapse.storage.DataStore):
|
|
as_api (synapse.appservice.api.ApplicationServiceApi):
|
|
"""
|
|
|
|
def __init__(self, clock, store, as_api):
|
|
self.clock = clock
|
|
self.store = store
|
|
self.as_api = as_api
|
|
|
|
# map from service id to recoverer instance
|
|
self.recoverers = {}
|
|
|
|
# for UTs
|
|
self.RECOVERER_CLASS = _Recoverer
|
|
|
|
async def send(
|
|
self,
|
|
service: ApplicationService,
|
|
events: List[EventBase],
|
|
ephemeral: List[JsonDict] = [],
|
|
):
|
|
try:
|
|
txn = await self.store.create_appservice_txn(
|
|
service=service, events=events, ephemeral=ephemeral
|
|
)
|
|
service_is_up = await self._is_service_up(service)
|
|
if service_is_up:
|
|
sent = await txn.send(self.as_api)
|
|
if sent:
|
|
await txn.complete(self.store)
|
|
else:
|
|
run_in_background(self._on_txn_fail, service)
|
|
except Exception:
|
|
logger.exception("Error creating appservice transaction")
|
|
run_in_background(self._on_txn_fail, service)
|
|
|
|
async def on_recovered(self, recoverer):
|
|
logger.info(
|
|
"Successfully recovered application service AS ID %s", recoverer.service.id
|
|
)
|
|
self.recoverers.pop(recoverer.service.id)
|
|
logger.info("Remaining active recoverers: %s", len(self.recoverers))
|
|
await self.store.set_appservice_state(
|
|
recoverer.service, ApplicationServiceState.UP
|
|
)
|
|
|
|
async def _on_txn_fail(self, service):
|
|
try:
|
|
await self.store.set_appservice_state(service, ApplicationServiceState.DOWN)
|
|
self.start_recoverer(service)
|
|
except Exception:
|
|
logger.exception("Error starting AS recoverer")
|
|
|
|
def start_recoverer(self, service):
|
|
"""Start a Recoverer for the given service
|
|
|
|
Args:
|
|
service (synapse.appservice.ApplicationService):
|
|
"""
|
|
logger.info("Starting recoverer for AS ID %s", service.id)
|
|
assert service.id not in self.recoverers
|
|
recoverer = self.RECOVERER_CLASS(
|
|
self.clock, self.store, self.as_api, service, self.on_recovered
|
|
)
|
|
self.recoverers[service.id] = recoverer
|
|
recoverer.recover()
|
|
logger.info("Now %i active recoverers", len(self.recoverers))
|
|
|
|
async def _is_service_up(self, service: ApplicationService) -> bool:
|
|
state = await self.store.get_appservice_state(service)
|
|
return state == ApplicationServiceState.UP or state is None
|
|
|
|
|
|
class _Recoverer:
|
|
"""Manages retries and backoff for a DOWN appservice.
|
|
|
|
We have one of these for each appservice which is currently considered DOWN.
|
|
|
|
Args:
|
|
clock (synapse.util.Clock):
|
|
store (synapse.storage.DataStore):
|
|
as_api (synapse.appservice.api.ApplicationServiceApi):
|
|
service (synapse.appservice.ApplicationService): the service we are managing
|
|
callback (callable[_Recoverer]): called once the service recovers.
|
|
"""
|
|
|
|
def __init__(self, clock, store, as_api, service, callback):
|
|
self.clock = clock
|
|
self.store = store
|
|
self.as_api = as_api
|
|
self.service = service
|
|
self.callback = callback
|
|
self.backoff_counter = 1
|
|
|
|
def recover(self):
|
|
def _retry():
|
|
run_as_background_process(
|
|
"as-recoverer-%s" % (self.service.id,), self.retry
|
|
)
|
|
|
|
delay = 2 ** self.backoff_counter
|
|
logger.info("Scheduling retries on %s in %fs", self.service.id, delay)
|
|
self.clock.call_later(delay, _retry)
|
|
|
|
def _backoff(self):
|
|
# cap the backoff to be around 8.5min => (2^9) = 512 secs
|
|
if self.backoff_counter < 9:
|
|
self.backoff_counter += 1
|
|
self.recover()
|
|
|
|
async def retry(self):
|
|
logger.info("Starting retries on %s", self.service.id)
|
|
try:
|
|
while True:
|
|
txn = await self.store.get_oldest_unsent_txn(self.service)
|
|
if not txn:
|
|
# nothing left: we're done!
|
|
await self.callback(self)
|
|
return
|
|
|
|
logger.info(
|
|
"Retrying transaction %s for AS ID %s", txn.id, txn.service.id
|
|
)
|
|
sent = await txn.send(self.as_api)
|
|
if not sent:
|
|
break
|
|
|
|
await txn.complete(self.store)
|
|
|
|
# reset the backoff counter and then process the next transaction
|
|
self.backoff_counter = 1
|
|
|
|
except Exception:
|
|
logger.exception("Unexpected error running retries")
|
|
|
|
# we didn't manage to send all of the transactions before we got an error of
|
|
# some flavour: reschedule the next retry.
|
|
self._backoff()
|