diff options
| -rw-r--r-- | changelog.d/17438.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/sliding_sync.py | 11 | ||||
| -rw-r--r-- | synapse/types/__init__.py | 65 | ||||
| -rw-r--r-- | tests/test_types.py | 71 |
4 files changed, 138 insertions, 10 deletions
diff --git a/changelog.d/17438.bugfix b/changelog.d/17438.bugfix new file mode 100644 index 0000000000..cff6eecd48 --- /dev/null +++ b/changelog.d/17438.bugfix @@ -0,0 +1 @@ +Fix rare bug where `/sync` would break for a user when using workers with multiple stream writers. diff --git a/synapse/handlers/sliding_sync.py b/synapse/handlers/sliding_sync.py index be98b379eb..1b5262d667 100644 --- a/synapse/handlers/sliding_sync.py +++ b/synapse/handlers/sliding_sync.py @@ -699,10 +699,17 @@ class SlidingSyncHandler: instance_to_max_stream_ordering_map[instance_name] = stream_ordering # Then assemble the `RoomStreamToken` + min_stream_pos = min(instance_to_max_stream_ordering_map.values()) membership_snapshot_token = RoomStreamToken( # Minimum position in the `instance_map` - stream=min(instance_to_max_stream_ordering_map.values()), - instance_map=immutabledict(instance_to_max_stream_ordering_map), + stream=min_stream_pos, + instance_map=immutabledict( + { + instance_name: stream_pos + for instance_name, stream_pos in instance_to_max_stream_ordering_map.items() + if stream_pos > min_stream_pos + } + ), ) # Since we fetched the users room list at some point in time after the from/to diff --git a/synapse/types/__init__.py b/synapse/types/__init__.py index b22a13ef01..3962ecc996 100644 --- a/synapse/types/__init__.py +++ b/synapse/types/__init__.py @@ -20,6 +20,7 @@ # # import abc +import logging import re import string from enum import Enum @@ -74,6 +75,9 @@ if TYPE_CHECKING: from synapse.storage.databases.main import DataStore, PurgeEventsStore from synapse.storage.databases.main.appservice import ApplicationServiceWorkerStore + +logger = logging.getLogger(__name__) + # Define a state map type from type/state_key to T (usually an event ID or # event) T = TypeVar("T") @@ -454,6 +458,8 @@ class AbstractMultiWriterStreamToken(metaclass=abc.ABCMeta): represented by a default `stream` attribute and a map of instance name to stream position of any writers that are ahead of the default stream position. + + The values in `instance_map` must be greater than the `stream` attribute. """ stream: int = attr.ib(validator=attr.validators.instance_of(int), kw_only=True) @@ -468,6 +474,15 @@ class AbstractMultiWriterStreamToken(metaclass=abc.ABCMeta): kw_only=True, ) + def __attrs_post_init__(self) -> None: + # Enforce that all instances have a value greater than the min stream + # position. + for i, v in self.instance_map.items(): + if v <= self.stream: + raise ValueError( + f"'instance_map' includes a stream position before the main 'stream' attribute. Instance: {i}" + ) + @classmethod @abc.abstractmethod async def parse(cls, store: "DataStore", string: str) -> "Self": @@ -494,6 +509,9 @@ class AbstractMultiWriterStreamToken(metaclass=abc.ABCMeta): for instance in set(self.instance_map).union(other.instance_map) } + # Filter out any redundant entries. + instance_map = {i: s for i, s in instance_map.items() if s > max_stream} + return attr.evolve( self, stream=max_stream, instance_map=immutabledict(instance_map) ) @@ -539,10 +557,15 @@ class AbstractMultiWriterStreamToken(metaclass=abc.ABCMeta): def bound_stream_token(self, max_stream: int) -> "Self": """Bound the stream positions to a maximum value""" + min_pos = min(self.stream, max_stream) return type(self)( - stream=min(self.stream, max_stream), + stream=min_pos, instance_map=immutabledict( - {k: min(s, max_stream) for k, s in self.instance_map.items()} + { + k: min(s, max_stream) + for k, s in self.instance_map.items() + if min(s, max_stream) > min_pos + } ), ) @@ -637,6 +660,8 @@ class RoomStreamToken(AbstractMultiWriterStreamToken): "Cannot set both 'topological' and 'instance_map' on 'RoomStreamToken'." ) + super().__attrs_post_init__() + @classmethod async def parse(cls, store: "PurgeEventsStore", string: str) -> "RoomStreamToken": try: @@ -651,6 +676,11 @@ class RoomStreamToken(AbstractMultiWriterStreamToken): instance_map = {} for part in parts[1:]: + if not part: + # Handle tokens of the form `m5~`, which were created by + # a bug + continue + key, value = part.split(".") instance_id = int(key) pos = int(value) @@ -666,7 +696,10 @@ class RoomStreamToken(AbstractMultiWriterStreamToken): except CancelledError: raise except Exception: - pass + # We log an exception here as even though this *might* be a client + # handing a bad token, its more likely that Synapse returned a bad + # token (and we really want to catch those!). + logger.exception("Failed to parse stream token: %r", string) raise SynapseError(400, "Invalid room stream token %r" % (string,)) @classmethod @@ -713,6 +746,8 @@ class RoomStreamToken(AbstractMultiWriterStreamToken): return self.instance_map.get(instance_name, self.stream) async def to_string(self, store: "DataStore") -> str: + """See class level docstring for information about the format.""" + if self.topological is not None: return "t%d-%d" % (self.topological, self.stream) elif self.instance_map: @@ -727,8 +762,10 @@ class RoomStreamToken(AbstractMultiWriterStreamToken): instance_id = await store.get_id_for_instance(name) entries.append(f"{instance_id}.{pos}") - encoded_map = "~".join(entries) - return f"m{self.stream}~{encoded_map}" + if entries: + encoded_map = "~".join(entries) + return f"m{self.stream}~{encoded_map}" + return f"s{self.stream}" else: return "s%d" % (self.stream,) @@ -756,6 +793,11 @@ class MultiWriterStreamToken(AbstractMultiWriterStreamToken): instance_map = {} for part in parts[1:]: + if not part: + # Handle tokens of the form `m5~`, which were created by + # a bug + continue + key, value = part.split(".") instance_id = int(key) pos = int(value) @@ -770,10 +812,15 @@ class MultiWriterStreamToken(AbstractMultiWriterStreamToken): except CancelledError: raise except Exception: - pass + # We log an exception here as even though this *might* be a client + # handing a bad token, its more likely that Synapse returned a bad + # token (and we really want to catch those!). + logger.exception("Failed to parse stream token: %r", string) raise SynapseError(400, "Invalid stream token %r" % (string,)) async def to_string(self, store: "DataStore") -> str: + """See class level docstring for information about the format.""" + if self.instance_map: entries = [] for name, pos in self.instance_map.items(): @@ -786,8 +833,10 @@ class MultiWriterStreamToken(AbstractMultiWriterStreamToken): instance_id = await store.get_id_for_instance(name) entries.append(f"{instance_id}.{pos}") - encoded_map = "~".join(entries) - return f"m{self.stream}~{encoded_map}" + if entries: + encoded_map = "~".join(entries) + return f"m{self.stream}~{encoded_map}" + return str(self.stream) else: return str(self.stream) diff --git a/tests/test_types.py b/tests/test_types.py index 944aa784fc..00adc65a5a 100644 --- a/tests/test_types.py +++ b/tests/test_types.py @@ -19,9 +19,18 @@ # # +from typing import Type +from unittest import skipUnless + +from immutabledict import immutabledict +from parameterized import parameterized_class + from synapse.api.errors import SynapseError from synapse.types import ( + AbstractMultiWriterStreamToken, + MultiWriterStreamToken, RoomAlias, + RoomStreamToken, UserID, get_domain_from_id, get_localpart_from_id, @@ -29,6 +38,7 @@ from synapse.types import ( ) from tests import unittest +from tests.utils import USE_POSTGRES_FOR_TESTS class IsMineIDTests(unittest.HomeserverTestCase): @@ -127,3 +137,64 @@ class MapUsernameTestCase(unittest.TestCase): # this should work with either a unicode or a bytes self.assertEqual(map_username_to_mxid_localpart("têst"), "t=c3=aast") self.assertEqual(map_username_to_mxid_localpart("têst".encode()), "t=c3=aast") + + +@parameterized_class( + ("token_type",), + [ + (MultiWriterStreamToken,), + (RoomStreamToken,), + ], + class_name_func=lambda cls, num, params_dict: f"{cls.__name__}_{params_dict['token_type'].__name__}", +) +class MultiWriterTokenTestCase(unittest.HomeserverTestCase): + """Tests for the different types of multi writer tokens.""" + + token_type: Type[AbstractMultiWriterStreamToken] + + def test_basic_token(self) -> None: + """Test that a simple stream token can be serialized and unserialized""" + store = self.hs.get_datastores().main + + token = self.token_type(stream=5) + + string_token = self.get_success(token.to_string(store)) + + if isinstance(token, RoomStreamToken): + self.assertEqual(string_token, "s5") + else: + self.assertEqual(string_token, "5") + + parsed_token = self.get_success(self.token_type.parse(store, string_token)) + self.assertEqual(parsed_token, token) + + @skipUnless(USE_POSTGRES_FOR_TESTS, "Requires Postgres") + def test_instance_map(self) -> None: + """Test for stream token with instance map""" + store = self.hs.get_datastores().main + + token = self.token_type(stream=5, instance_map=immutabledict({"foo": 6})) + + string_token = self.get_success(token.to_string(store)) + self.assertEqual(string_token, "m5~1.6") + + parsed_token = self.get_success(self.token_type.parse(store, string_token)) + self.assertEqual(parsed_token, token) + + def test_instance_map_assertion(self) -> None: + """Test that we assert values in the instance map are greater than the + min stream position""" + + with self.assertRaises(ValueError): + self.token_type(stream=5, instance_map=immutabledict({"foo": 4})) + + with self.assertRaises(ValueError): + self.token_type(stream=5, instance_map=immutabledict({"foo": 5})) + + def test_parse_bad_token(self) -> None: + """Test that we can parse tokens produced by a bug in Synapse of the + form `m5~`""" + store = self.hs.get_datastores().main + + parsed_token = self.get_success(self.token_type.parse(store, "m5~")) + self.assertEqual(parsed_token, self.token_type(stream=5)) |