Move stream catchup to workers.

synapse/replication/tcp/client.py

@@ -55,6 +55,7 @@ class ReplicationClientFactory(ReconnectingClientFactory):
         self.client_name = client_name
         self.handler = handler
         self.server_name = hs.config.server_name
+        self.hs = hs
         self._clock = hs.get_clock()  # As self.clock is defined in super class
 
         hs.get_reactor().addSystemEventTrigger("before", "shutdown", self.stopTrying)
@@ -65,7 +66,7 @@ class ReplicationClientFactory(ReconnectingClientFactory):
     def buildProtocol(self, addr):
         logger.info("Connected to replication: %r", addr)
         return ClientReplicationStreamProtocol(
-            self.client_name, self.server_name, self._clock, self.handler
+            self.hs, self.client_name, self.server_name, self._clock, self.handler,
         )
 
     def clientConnectionLost(self, connector, reason):

synapse/replication/tcp/protocol.py

@@ -82,7 +82,8 @@ from synapse.replication.tcp.commands import (
     SyncCommand,
     UserSyncCommand,
 )
-from synapse.replication.tcp.streams import STREAMS_MAP
+from synapse.replication.tcp.streams import STREAMS_MAP, Stream
+from synapse.server import HomeServer
 from synapse.types import Collection
 from synapse.util import Clock
 from synapse.util.stringutils import random_string
@@ -414,9 +415,6 @@ class ServerReplicationStreamProtocol(BaseReplicationStreamProtocol):
         # The streams the client has subscribed to and is up to date with
         self.replication_streams = set()  # type: Set[str]
 
-        # The streams the client is currently subscribing to.
-        self.connecting_streams = set()  # type:  Set[str]
-
         # Map from stream name to list of updates to send once we've finished
         # subscribing the client to the stream.
         self.pending_rdata = {}  # type: Dict[str, List[Tuple[int, Any]]]
@@ -482,67 +480,21 @@ class ServerReplicationStreamProtocol(BaseReplicationStreamProtocol):
         are queued and sent once we've sent down any missed updates.
         """
         self.replication_streams.discard(stream_name)
-        self.connecting_streams.add(stream_name)
 
         try:
-            limited = True
+            # Get current stream position.
-            while limited:
+            current_token = self.streamer.get_stream_token(stream_name)
-                # Get missing updates
-                (
-                    updates,
-                    current_token,
-                    limited,
-                ) = await self.streamer.get_stream_updates(stream_name, token)
-
-                # Send all the missing updates
-                for update in updates:
-                    token, row = update[0], update[1]
-                    self.send_command(RdataCommand(stream_name, token, row))
 
             # We send a POSITION command to ensure that they have an up to
             # date token (especially useful if we didn't send any updates
             # above)
             self.send_command(PositionCommand(stream_name, current_token))
 
-            # Now we can send any updates that came in while we were subscribing
-            pending_rdata = self.pending_rdata.pop(stream_name, [])
-            updates = []
-            for token, update in pending_rdata:
-                # If the token is null, it is part of a batch update. Batches
-                # are multiple updates that share a single token. To denote
-                # this, the token is set to None for all tokens in the batch
-                # except for the last. If we find a None token, we keep looking
-                # through tokens until we find one that is not None and then
-                # process all previous updates in the batch as if they had the
-                # final token.
-                if token is None:
-                    # Store this update as part of a batch
-                    updates.append(update)
-                    continue
-
-                if token <= current_token:
-                    # This update or batch of updates is older than
-                    # current_token, dismiss it
-                    updates = []
-                    continue
-
-                updates.append(update)
-
-                # Send all updates that are part of this batch with the
-                # found token
-                for update in updates:
-                    self.send_command(RdataCommand(stream_name, token, update))
-
-                # Clear stored updates
-                updates = []
-
             # They're now fully subscribed
             self.replication_streams.add(stream_name)
         except Exception as e:
             logger.exception("[%s] Failed to handle REPLICATE command", self.id())
             self.send_error("failed to handle replicate: %r", e)
-        finally:
-            self.connecting_streams.discard(stream_name)
 
     def stream_update(self, stream_name, token, data):
         """Called when a new update is available to stream to clients.
@@ -552,10 +504,6 @@ class ServerReplicationStreamProtocol(BaseReplicationStreamProtocol):
         if stream_name in self.replication_streams:
             # The client is subscribed to the stream
             self.send_command(RdataCommand(stream_name, token, data))
-        elif stream_name in self.connecting_streams:
-            # The client is being subscribed to the stream
-            logger.debug("[%s] Queuing RDATA %r %r", self.id(), stream_name, token)
-            self.pending_rdata.setdefault(stream_name, []).append((token, data))
         else:
             # The client isn't subscribed
             logger.debug("[%s] Dropping RDATA %r %r", self.id(), stream_name, token)
@@ -642,6 +590,7 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
 
     def __init__(
         self,
+        hs: HomeServer,
         client_name: str,
         server_name: str,
         clock: Clock,
@@ -653,6 +602,10 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
         self.server_name = server_name
         self.handler = handler
 
+        self.streams = {
+            stream.NAME: stream(hs) for stream in STREAMS_MAP.values()
+        }  # type: Dict[str, Stream]
+
         # Set of stream names that have been subscribe to, but haven't yet
         # caught up with. This is used to track when the client has been fully
         # connected to the remote.
@@ -660,7 +613,7 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
 
         # Map of stream to batched updates. See RdataCommand for info on how
         # batching works.
-        self.pending_batches = {}  # type: Dict[str, Any]
+        self.pending_batches = {}  # type: Dict[str, List[Any]]
 
     def connectionMade(self):
         self.send_command(NameCommand(self.client_name))
@@ -701,7 +654,7 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
             )
             raise
 
-        if cmd.token is None:
+        if cmd.token is None or stream_name in self.streams_connecting:
             # I.e. this is part of a batch of updates for this stream. Batch
             # until we get an update for the stream with a non None token
             self.pending_batches.setdefault(stream_name, []).append(row)
@@ -711,14 +664,46 @@ class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
             rows.append(row)
             await self.handler.on_rdata(stream_name, cmd.token, rows)
 
-    async def on_POSITION(self, cmd):
+    async def on_POSITION(self, cmd: PositionCommand):
+        stream = self.streams.get(cmd.stream_name)
+        if not stream:
+            logger.error("Got POSITION for unknown stream: %s", cmd.stream_name)
+            return
+
+        # Find where we previously streamed up to.
+        current_token = self.handler.get_streams_to_replicate().get(cmd.stream_name)
+        if current_token is None:
+            logger.warning(
+                "Got POSITION for stream we're not subscribed to: %s", cmd.stream_name
+            )
+            return
+
+        # Fetch all updates between then and now.
+        limited = True
+        while limited:
+            updates, current_token, limited = await stream.get_updates_since(
+                current_token, cmd.token
+            )
+            if updates:
+                await self.handler.on_rdata(
+                    cmd.stream_name,
+                    current_token,
+                    [stream.parse_row(update[1]) for update in updates],
+                )
+
+        # We've now caught up to position sent to us, notify handler.
+        await self.handler.on_position(cmd.stream_name, cmd.token)
+
         # When we get a `POSITION` command it means we've finished getting
         # missing updates for the given stream, and are now up to date.
         self.streams_connecting.discard(cmd.stream_name)
         if not self.streams_connecting:
             self.handler.finished_connecting()
 
-        await self.handler.on_position(cmd.stream_name, cmd.token)
+        # Handle any RDATA that came in while we were catching up.
+        rows = self.pending_batches.pop(cmd.stream_name, [])
+        if rows:
+            await self.handler.on_rdata(cmd.stream_name, rows[-1].token, rows)
 
     async def on_SYNC(self, cmd):
         self.handler.on_sync(cmd.data)

synapse/replication/tcp/resource.py

@@ -227,8 +227,7 @@ class ReplicationStreamer(object):
             self.pending_updates = False
             self.is_looping = False
 
-    @measure_func("repl.get_stream_updates")
+    def get_stream_token(self, stream_name):
-    async def get_stream_updates(self, stream_name, token):
         """For a given stream get all updates since token. This is called when
         a client first subscribes to a stream.
         """
@@ -236,7 +235,7 @@ class ReplicationStreamer(object):
         if not stream:
             raise Exception("unknown stream %s", stream_name)
 
-        return await stream.get_updates_since(token, stream.current_token())
+        return stream.current_token()
 
     @measure_func("repl.federation_ack")
     def federation_ack(self, token):

synapse/replication/tcp/streams/__init__.py

@@ -27,7 +27,8 @@ Each stream is defined by the following information:
 
 from typing import Dict, Type
 
-from . import _base, events, federation
+from synapse.replication.tcp.streams import _base, events, federation
+from synapse.replication.tcp.streams._base import Stream
 
 STREAMS_MAP = {
     stream.NAME: stream
@@ -50,3 +51,6 @@ STREAMS_MAP = {
         _base.UserSignatureStream,
     )
 }  # type: Dict[str, Type[_base.Stream]]
+
+
+__all__ = ["Stream", "STREAMS_MAP"]

tests/replication/tcp/streams/_base.py

@@ -12,6 +12,7 @@
 # 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.
+
 from mock import Mock
 
 from synapse.replication.tcp.commands import ReplicateCommand
@@ -29,19 +30,37 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
         # build a replication server
         server_factory = ReplicationStreamProtocolFactory(self.hs)
         self.streamer = server_factory.streamer
-        server = server_factory.buildProtocol(None)
+        self.server = server_factory.buildProtocol(None)
 
-        # build a replication client, with a dummy handler
+        self.test_handler = Mock(wraps=TestReplicationClientHandler())
-        handler_factory = Mock()
-        self.test_handler = TestReplicationClientHandler()
-        self.test_handler.factory = handler_factory
         self.client = ClientReplicationStreamProtocol(
-            "client", "test", clock, self.test_handler
+            hs, "client", "test", clock, self.test_handler,
         )
 
-        # wire them together
+        self._client_transport = None
-        self.client.makeConnection(FakeTransport(server, reactor))
+        self._server_transport = None
-        server.makeConnection(FakeTransport(self.client, reactor))
+
+    def reconnect(self):
+        if self._client_transport:
+            self.client.close()
+
+        if self._server_transport:
+            self.server.close()
+
+        self._client_transport = FakeTransport(self.server, self.reactor)
+        self.client.makeConnection(self._client_transport)
+
+        self._server_transport = FakeTransport(self.client, self.reactor)
+        self.server.makeConnection(self._server_transport)
+
+    def disconnect(self):
+        if self._client_transport:
+            self._client_transport = None
+            self.client.close()
+
+        if self._server_transport:
+            self._server_transport = None
+            self.server.close()
 
     def replicate(self):
         """Tell the master side of replication that something has happened, and then
@@ -59,10 +78,15 @@ class TestReplicationClientHandler(object):
     """Drop-in for ReplicationClientHandler which just collects RDATA rows"""
 
     def __init__(self):
-        self.received_rdata_rows = []
+        self.streams = set()
+        self._received_rdata_rows = []
 
     def get_streams_to_replicate(self):
-        return {}
+        positions = {s: 0 for s in self.streams}
+        for stream, token, _ in self._received_rdata_rows:
+            if stream in self.streams:
+                positions[stream] = max(token, positions.get(stream, 0))
+        return positions
 
     def get_currently_syncing_users(self):
         return []
@@ -73,6 +97,9 @@ class TestReplicationClientHandler(object):
     def finished_connecting(self):
         pass
 
+    async def on_position(self, stream_name, token):
+        """Called when we get new position data."""
+
     async def on_rdata(self, stream_name, token, rows):
         for r in rows:
-            self.received_rdata_rows.append((stream_name, token, r))
+            self._received_rdata_rows.append((stream_name, token, r))

tests/replication/tcp/streams/test_receipts.py

@@ -17,30 +17,64 @@ from synapse.replication.tcp.streams._base import ReceiptsStreamRow
 from tests.replication.tcp.streams._base import BaseStreamTestCase
 
 USER_ID = "@feeling:blue"
-ROOM_ID = "!room:blue"
-EVENT_ID = "$event:blue"
 
 
 class ReceiptsStreamTestCase(BaseStreamTestCase):
     def test_receipt(self):
+        self.reconnect()
+
         # make the client subscribe to the receipts stream
         self.replicate_stream("receipts", "NOW")
+        self.test_handler.streams.add("receipts")
 
         # tell the master to send a new receipt
         self.get_success(
             self.hs.get_datastore().insert_receipt(
-                ROOM_ID, "m.read", USER_ID, [EVENT_ID], {"a": 1}
+                "!room:blue", "m.read", USER_ID, ["$event:blue"], {"a": 1}
             )
         )
         self.replicate()
 
         # there should be one RDATA command
-        rdata_rows = self.test_handler.received_rdata_rows
+        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, "receipts")
         self.assertEqual(1, len(rdata_rows))
-        self.assertEqual(rdata_rows[0][0], "receipts")
+        row = rdata_rows[0]  # type: ReceiptsStreamRow
-        row = rdata_rows[0][2]  # type: ReceiptsStreamRow
+        self.assertEqual("!room:blue", row.room_id)
-        self.assertEqual(ROOM_ID, row.room_id)
         self.assertEqual("m.read", row.receipt_type)
         self.assertEqual(USER_ID, row.user_id)
-        self.assertEqual(EVENT_ID, row.event_id)
+        self.assertEqual("$event:blue", row.event_id)
         self.assertEqual({"a": 1}, row.data)
+
+        # Now let's disconnect and insert some data.
+        self.disconnect()
+
+        self.test_handler.on_rdata.reset_mock()
+
+        self.get_success(
+            self.hs.get_datastore().insert_receipt(
+                "!room2:blue", "m.read", USER_ID, ["$event2:foo"], {"a": 2}
+            )
+        )
+        self.replicate()
+
+        # Nothing should have happened as we are disconnected
+        self.test_handler.on_rdata.assert_not_called()
+
+        self.reconnect()
+        self.pump(0.1)
+
+        # We should now have caught up and get the missing data
+        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, "receipts")
+        self.assertEqual(token, 3)
+        self.assertEqual(1, len(rdata_rows))
+
+        row = rdata_rows[0]  # type: ReceiptsStreamRow
+        self.assertEqual("!room2:blue", row.room_id)
+        self.assertEqual("m.read", row.receipt_type)
+        self.assertEqual(USER_ID, row.user_id)
+        self.assertEqual("$event2:foo", row.event_id)
+        self.assertEqual({"a": 2}, row.data)