Discard RDATA from already seen positions. (#7648)

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Patrick Cloke 2020-06-15 08:44:54 -04:00 committed by GitHub
parent bd6dc17221
commit 7d2532be36
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6 changed files with 175 additions and 27 deletions

1
changelog.d/7648.bugfix Normal file
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@ -0,0 +1 @@
In working mode, ensure that replicated data has not already been received.

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@ -738,6 +738,11 @@ class GenericWorkerReplicationHandler(ReplicationDataHandler):
except Exception:
logger.exception("Error processing replication")
async def on_position(self, stream_name: str, instance_name: str, token: int):
await super().on_position(stream_name, instance_name, token)
# Also call on_rdata to ensure that stream positions are properly reset.
await self.on_rdata(stream_name, instance_name, token, [])
def stop_pusher(self, user_id, app_id, pushkey):
if not self.notify_pushers:
return

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@ -149,7 +149,7 @@ class RdataCommand(Command):
class PositionCommand(Command):
"""Sent by the server to tell the client the stream postition without
"""Sent by the server to tell the client the stream position without
needing to send an RDATA.
Format::
@ -188,7 +188,7 @@ class ErrorCommand(_SimpleCommand):
class PingCommand(_SimpleCommand):
"""Sent by either side as a keep alive. The data is arbitary (often timestamp)
"""Sent by either side as a keep alive. The data is arbitrary (often timestamp)
"""
NAME = "PING"

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@ -112,8 +112,8 @@ class ReplicationCommandHandler:
"replication_position", clock=self._clock
)
# Map of stream to batched updates. See RdataCommand for info on how
# batching works.
# Map of stream name to batched updates. See RdataCommand for info on
# how batching works.
self._pending_batches = {} # type: Dict[str, List[Any]]
# The factory used to create connections.
@ -123,7 +123,8 @@ class ReplicationCommandHandler:
# outgoing replication commands to.)
self._connections = [] # type: List[AbstractConnection]
# For each connection, the incoming streams that are coming from that connection
# For each connection, the incoming stream names that are coming from
# that connection.
self._streams_by_connection = {} # type: Dict[AbstractConnection, Set[str]]
LaterGauge(
@ -310,6 +311,27 @@ class ReplicationCommandHandler:
# Check if this is the last of a batch of updates
rows = self._pending_batches.pop(stream_name, [])
rows.append(row)
stream = self._streams.get(stream_name)
if not stream:
logger.error("Got RDATA for unknown stream: %s", stream_name)
return
# Find where we previously streamed up to.
current_token = stream.current_token(cmd.instance_name)
# Discard this data if this token is earlier than the current
# position. Note that streams can be reset (in which case you
# expect an earlier token), but that must be preceded by a
# POSITION command.
if cmd.token <= current_token:
logger.debug(
"Discarding RDATA from stream %s at position %s before previous position %s",
stream_name,
cmd.token,
current_token,
)
else:
await self.on_rdata(stream_name, cmd.instance_name, cmd.token, rows)
async def on_rdata(

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@ -17,6 +17,7 @@ from typing import List, Optional
from synapse.api.constants import EventTypes, Membership
from synapse.events import EventBase
from synapse.replication.tcp.commands import RdataCommand
from synapse.replication.tcp.streams._base import _STREAM_UPDATE_TARGET_ROW_COUNT
from synapse.replication.tcp.streams.events import (
EventsStreamCurrentStateRow,
@ -66,11 +67,6 @@ class EventsStreamTestCase(BaseStreamTestCase):
# also one state event
state_event = self._inject_state_event()
# tell the notifier to catch up to avoid duplicate rows.
# workaround for https://github.com/matrix-org/synapse/issues/7360
# FIXME remove this when the above is fixed
self.replicate()
# check we're testing what we think we are: no rows should yet have been
# received
self.assertEqual([], self.test_handler.received_rdata_rows)
@ -174,11 +170,6 @@ class EventsStreamTestCase(BaseStreamTestCase):
# one more bit of state that doesn't get rolled back
state2 = self._inject_state_event()
# tell the notifier to catch up to avoid duplicate rows.
# workaround for https://github.com/matrix-org/synapse/issues/7360
# FIXME remove this when the above is fixed
self.replicate()
# check we're testing what we think we are: no rows should yet have been
# received
self.assertEqual([], self.test_handler.received_rdata_rows)
@ -327,11 +318,6 @@ class EventsStreamTestCase(BaseStreamTestCase):
prev_events = [e.event_id]
pl_events.append(e)
# tell the notifier to catch up to avoid duplicate rows.
# workaround for https://github.com/matrix-org/synapse/issues/7360
# FIXME remove this when the above is fixed
self.replicate()
# check we're testing what we think we are: no rows should yet have been
# received
self.assertEqual([], self.test_handler.received_rdata_rows)
@ -378,6 +364,64 @@ class EventsStreamTestCase(BaseStreamTestCase):
self.assertEqual([], received_rows)
def test_backwards_stream_id(self):
"""
Test that RDATA that comes after the current position should be discarded.
"""
# disconnect, so that we can stack up some changes
self.disconnect()
# Generate an events. We inject them using inject_event so that they are
# not send out over replication until we call self.replicate().
event = self._inject_test_event()
# check we're testing what we think we are: no rows should yet have been
# received
self.assertEqual([], self.test_handler.received_rdata_rows)
# now reconnect to pull the updates
self.reconnect()
self.replicate()
# We should have received the expected single row (as well as various
# cache invalidation updates which we ignore).
received_rows = [
row for row in self.test_handler.received_rdata_rows if row[0] == "events"
]
# There should be a single received row.
self.assertEqual(len(received_rows), 1)
stream_name, token, row = received_rows[0]
self.assertEqual("events", stream_name)
self.assertIsInstance(row, EventsStreamRow)
self.assertEqual(row.type, "ev")
self.assertIsInstance(row.data, EventsStreamEventRow)
self.assertEqual(row.data.event_id, event.event_id)
# Reset the data.
self.test_handler.received_rdata_rows = []
# Save the current token for later.
worker_events_stream = self.worker_hs.get_replication_streams()["events"]
prev_token = worker_events_stream.current_token("master")
# Manually send an old RDATA command, which should get dropped. This
# re-uses the row from above, but with an earlier stream token.
self.hs.get_tcp_replication().send_command(
RdataCommand("events", "master", 1, row)
)
# No updates have been received (because it was discard as old).
received_rows = [
row for row in self.test_handler.received_rdata_rows if row[0] == "events"
]
self.assertEqual(len(received_rows), 0)
# Ensure the stream has not gone backwards.
current_token = worker_events_stream.current_token("master")
self.assertGreaterEqual(current_token, prev_token)
event_count = 0
def _inject_test_event(

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@ -16,10 +16,15 @@ from mock import Mock
from synapse.handlers.typing import RoomMember
from synapse.replication.tcp.streams import TypingStream
from synapse.util.caches.stream_change_cache import StreamChangeCache
from tests.replication._base import BaseStreamTestCase
USER_ID = "@feeling:blue"
USER_ID_2 = "@da-ba-dee:blue"
ROOM_ID = "!bar:blue"
ROOM_ID_2 = "!foo:blue"
class TypingStreamTestCase(BaseStreamTestCase):
@ -29,11 +34,9 @@ class TypingStreamTestCase(BaseStreamTestCase):
def test_typing(self):
typing = self.hs.get_typing_handler()
room_id = "!bar:blue"
self.reconnect()
typing._push_update(member=RoomMember(room_id, USER_ID), typing=True)
typing._push_update(member=RoomMember(ROOM_ID, USER_ID), typing=True)
self.reactor.advance(0)
@ -46,7 +49,7 @@ class TypingStreamTestCase(BaseStreamTestCase):
self.assertEqual(stream_name, "typing")
self.assertEqual(1, len(rdata_rows))
row = rdata_rows[0] # type: TypingStream.TypingStreamRow
self.assertEqual(room_id, row.room_id)
self.assertEqual(ROOM_ID, row.room_id)
self.assertEqual([USER_ID], row.user_ids)
# Now let's disconnect and insert some data.
@ -54,7 +57,7 @@ class TypingStreamTestCase(BaseStreamTestCase):
self.test_handler.on_rdata.reset_mock()
typing._push_update(member=RoomMember(room_id, USER_ID), typing=False)
typing._push_update(member=RoomMember(ROOM_ID, USER_ID), typing=False)
self.test_handler.on_rdata.assert_not_called()
@ -73,5 +76,78 @@ class TypingStreamTestCase(BaseStreamTestCase):
self.assertEqual(stream_name, "typing")
self.assertEqual(1, len(rdata_rows))
row = rdata_rows[0]
self.assertEqual(room_id, row.room_id)
self.assertEqual(ROOM_ID, row.room_id)
self.assertEqual([], row.user_ids)
def test_reset(self):
"""
Test what happens when a typing stream resets.
This is emulated by jumping the stream ahead, then reconnecting (which
sends the proper position and RDATA).
"""
typing = self.hs.get_typing_handler()
self.reconnect()
typing._push_update(member=RoomMember(ROOM_ID, USER_ID), typing=True)
self.reactor.advance(0)
# We should now see an attempt to connect to the master
request = self.handle_http_replication_attempt()
self.assert_request_is_get_repl_stream_updates(request, "typing")
self.test_handler.on_rdata.assert_called_once()
stream_name, _, token, rdata_rows = self.test_handler.on_rdata.call_args[0]
self.assertEqual(stream_name, "typing")
self.assertEqual(1, len(rdata_rows))
row = rdata_rows[0] # type: TypingStream.TypingStreamRow
self.assertEqual(ROOM_ID, row.room_id)
self.assertEqual([USER_ID], row.user_ids)
# Push the stream forward a bunch so it can be reset.
for i in range(100):
typing._push_update(
member=RoomMember(ROOM_ID, "@test%s:blue" % i), typing=True
)
self.reactor.advance(0)
# Disconnect.
self.disconnect()
# Reset the typing handler
self.hs.get_replication_streams()["typing"].last_token = 0
self.hs.get_tcp_replication()._streams["typing"].last_token = 0
typing._latest_room_serial = 0
typing._typing_stream_change_cache = StreamChangeCache(
"TypingStreamChangeCache", typing._latest_room_serial
)
typing._reset()
# Reconnect.
self.reconnect()
self.pump(0.1)
# We should now see an attempt to connect to the master
request = self.handle_http_replication_attempt()
self.assert_request_is_get_repl_stream_updates(request, "typing")
# Reset the test code.
self.test_handler.on_rdata.reset_mock()
self.test_handler.on_rdata.assert_not_called()
# Push additional data.
typing._push_update(member=RoomMember(ROOM_ID_2, USER_ID_2), typing=False)
self.reactor.advance(0)
self.test_handler.on_rdata.assert_called_once()
stream_name, _, token, rdata_rows = self.test_handler.on_rdata.call_args[0]
self.assertEqual(stream_name, "typing")
self.assertEqual(1, len(rdata_rows))
row = rdata_rows[0]
self.assertEqual(ROOM_ID_2, row.room_id)
self.assertEqual([], row.user_ids)
# The token should have been reset.
self.assertEqual(token, 1)