Move client command handling out of TCP protocol

changelog.d/7185.misc

@@ -0,0 +1 @@
+Move client command handling out of TCP protocol.

synapse/app/admin_cmd.py

@@ -43,7 +43,6 @@
 from synapse.replication.slave.storage.receipts import SlavedReceiptsStore
 from synapse.replication.slave.storage.registration import SlavedRegistrationStore
 from synapse.replication.slave.storage.room import RoomStore
-from synapse.replication.tcp.client import ReplicationClientHandler
 from synapse.server import HomeServer
 from synapse.util.logcontext import LoggingContext
 from synapse.util.versionstring import get_version_string
@@ -79,17 +78,6 @@ def _listen_http(self, listener_config):
     def start_listening(self, listeners):
         pass
 
-    def build_tcp_replication(self):
-        return AdminCmdReplicationHandler(self)
-
-
-class AdminCmdReplicationHandler(ReplicationClientHandler):
-    async def on_rdata(self, stream_name, token, rows):
-        pass
-
-    def get_streams_to_replicate(self):
-        return {}
-
 
 @defer.inlineCallbacks
 def export_data_command(hs, args):

synapse/app/generic_worker.py

@@ -64,7 +64,7 @@
 from synapse.replication.slave.storage.registration import SlavedRegistrationStore
 from synapse.replication.slave.storage.room import RoomStore
 from synapse.replication.slave.storage.transactions import SlavedTransactionStore
-from synapse.replication.tcp.client import ReplicationClientHandler
+from synapse.replication.tcp.client import ReplicationDataHandler
 from synapse.replication.tcp.commands import ClearUserSyncsCommand
 from synapse.replication.tcp.streams import (
     AccountDataStream,
@@ -603,7 +603,7 @@ def start_listening(self, listeners):
     def remove_pusher(self, app_id, push_key, user_id):
         self.get_tcp_replication().send_remove_pusher(app_id, push_key, user_id)
 
-    def build_tcp_replication(self):
+    def build_replication_data_handler(self):
         return GenericWorkerReplicationHandler(self)
 
     def build_presence_handler(self):
@@ -613,7 +613,7 @@ def build_typing_handler(self):
         return GenericWorkerTyping(self)
 
 
-class GenericWorkerReplicationHandler(ReplicationClientHandler):
+class GenericWorkerReplicationHandler(ReplicationDataHandler):
     def __init__(self, hs):
         super(GenericWorkerReplicationHandler, self).__init__(hs.get_datastore())
 
@@ -644,9 +644,6 @@ def get_streams_to_replicate(self):
             args.update(self.send_handler.stream_positions())
         return args
 
-    def get_currently_syncing_users(self):
-        return self.presence_handler.get_currently_syncing_users()
-
     async def process_and_notify(self, stream_name, token, rows):
         try:
             if self.send_handler:

synapse/replication/tcp/__init__.py

@@ -20,11 +20,31 @@
 
 
 Structure of the module:
- * client.py   - the client classes used for workers to connect to master
+ * handler.py  - the classes used to handle sending/receiving commands to
+                 replication
  * command.py  - the definitions of all the valid commands
- * protocol.py - contains bot the client and server protocol implementations,
-                 these should not be used directly
- * resource.py - the server classes that accepts and handle client connections
- * streams.py  - the definitons of all the valid streams
+ * protocol.py - the TCP protocol classes
+ * resource.py - handles streaming stream updates to replications
+ * streams/    - the definitons of all the valid streams
 
+
+The general interaction of the classes are:
+
+        +---------------------+
+        | ReplicationStreamer |
+        +---------------------+
+                    |
+                    v
+        +---------------------------+     +----------------------+
+        | ReplicationCommandHandler |---->|ReplicationDataHandler|
+        +---------------------------+     +----------------------+
+                    | ^
+                    v |
+            +-------------+
+            | Protocols   |
+            | (TCP/redis) |
+            +-------------+
+
+Where the ReplicationDataHandler (or subclasses) handles incoming stream
+updates.
 """

synapse/replication/tcp/client.py

@@ -16,26 +16,16 @@
 """
 
 import logging
-from typing import Dict, List, Optional
+from typing import TYPE_CHECKING, Dict
 
-from twisted.internet import defer
 from twisted.internet.protocol import ReconnectingClientFactory
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
-from synapse.replication.tcp.protocol import (
-    AbstractReplicationClientHandler,
-    ClientReplicationStreamProtocol,
-)
-
-from .commands import (
-    Command,
-    FederationAckCommand,
-    InvalidateCacheCommand,
-    RemoteServerUpCommand,
-    RemovePusherCommand,
-    UserIpCommand,
-    UserSyncCommand,
-)
+from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+    from synapse.replication.tcp.handler import ReplicationCommandHandler
 
 logger = logging.getLogger(__name__)
 
@@ -44,16 +34,20 @@ class ReplicationClientFactory(ReconnectingClientFactory):
     """Factory for building connections to the master. Will reconnect if the
     connection is lost.
 
-    Accepts a handler that will be called when new data is available or data
-    is required.
+    Accepts a handler that is passed to `ClientReplicationStreamProtocol`.
     """
 
     initialDelay = 0.1
     maxDelay = 1  # Try at least once every N seconds
 
-    def __init__(self, hs, client_name, handler: AbstractReplicationClientHandler):
+    def __init__(
+        self,
+        hs: "HomeServer",
+        client_name: str,
+        command_handler: "ReplicationCommandHandler",
+    ):
         self.client_name = client_name
-        self.handler = handler
+        self.command_handler = command_handler
         self.server_name = hs.config.server_name
         self.hs = hs
         self._clock = hs.get_clock()  # As self.clock is defined in super class
@@ -66,7 +60,11 @@ def startedConnecting(self, connector):
     def buildProtocol(self, addr):
         logger.info("Connected to replication: %r", addr)
         return ClientReplicationStreamProtocol(
-            self.hs, self.client_name, self.server_name, self._clock, self.handler,
+            self.hs,
+            self.client_name,
+            self.server_name,
+            self._clock,
+            self.command_handler,
         )
 
     def clientConnectionLost(self, connector, reason):
@@ -78,41 +76,17 @@ def clientConnectionFailed(self, connector, reason):
         ReconnectingClientFactory.clientConnectionFailed(self, connector, reason)
 
 
-class ReplicationClientHandler(AbstractReplicationClientHandler):
-    """A base handler that can be passed to the ReplicationClientFactory.
+class ReplicationDataHandler:
+    """Handles incoming stream updates from replication.
 
-    By default proxies incoming replication data to the SlaveStore.
+    This instance notifies the slave data store about updates. Can be subclassed
+    to handle updates in additional ways.
     """
 
     def __init__(self, store: BaseSlavedStore):
         self.store = store
 
-        # The current connection. None if we are currently (re)connecting
-        self.connection = None
-
-        # Any pending commands to be sent once a new connection has been
-        # established
-        self.pending_commands = []  # type: List[Command]
-
-        # Map from string -> deferred, to wake up when receiveing a SYNC with
-        # the given string.
-        # Used for tests.
-        self.awaiting_syncs = {}  # type: Dict[str, defer.Deferred]
-
-        # The factory used to create connections.
-        self.factory = None  # type: Optional[ReplicationClientFactory]
-
-    def start_replication(self, hs):
-        """Helper method to start a replication connection to the remote server
-        using TCP.
-        """
-        client_name = hs.config.worker_name
-        self.factory = ReplicationClientFactory(hs, client_name, self)
-        host = hs.config.worker_replication_host
-        port = hs.config.worker_replication_port
-        hs.get_reactor().connectTCP(host, port, self.factory)
-
-    async def on_rdata(self, stream_name, token, rows):
+    async def on_rdata(self, stream_name: str, token: int, rows: list):
         """Called to handle a batch of replication data with a given stream token.
 
         By default this just pokes the slave store. Can be overridden in subclasses to
@@ -124,30 +98,8 @@ async def on_rdata(self, stream_name, token, rows):
             rows (list): a list of Stream.ROW_TYPE objects as returned by
                 Stream.parse_row.
         """
-        logger.debug("Received rdata %s -> %s", stream_name, token)
         self.store.process_replication_rows(stream_name, token, rows)
 
-    async def on_position(self, stream_name, token):
-        """Called when we get new position data. By default this just pokes
-        the slave store.
-
-        Can be overriden in subclasses to handle more.
-        """
-        self.store.process_replication_rows(stream_name, token, [])
-
-    def on_sync(self, data):
-        """When we received a SYNC we wake up any deferreds that were waiting
-        for the sync with the given data.
-
-        Used by tests.
-        """
-        d = self.awaiting_syncs.pop(data, None)
-        if d:
-            d.callback(data)
-
-    def on_remote_server_up(self, server: str):
-        """Called when get a new REMOTE_SERVER_UP command."""
-
     def get_streams_to_replicate(self) -> Dict[str, int]:
         """Called when a new connection has been established and we need to
         subscribe to streams.
@@ -163,85 +115,10 @@ def get_streams_to_replicate(self) -> Dict[str, int]:
             args["account_data"] = user_account_data
         elif room_account_data:
             args["account_data"] = room_account_data
-
         return args
 
-    def get_currently_syncing_users(self):
-        """Get the list of currently syncing users (if any). This is called
-        when a connection has been established and we need to send the
-        currently syncing users. (Overriden by the synchrotron's only)
-        """
-        return []
-
-    def send_command(self, cmd):
-        """Send a command to master (when we get establish a connection if we
-        don't have one already.)
-        """
-        if self.connection:
-            self.connection.send_command(cmd)
-        else:
-            logger.warning("Queuing command as not connected: %r", cmd.NAME)
-            self.pending_commands.append(cmd)
-
-    def send_federation_ack(self, token):
-        """Ack data for the federation stream. This allows the master to drop
-        data stored purely in memory.
-        """
-        self.send_command(FederationAckCommand(token))
-
-    def send_user_sync(self, instance_id, user_id, is_syncing, last_sync_ms):
-        """Poke the master that a user has started/stopped syncing.
-        """
-        self.send_command(
-            UserSyncCommand(instance_id, user_id, is_syncing, last_sync_ms)
-        )
-
-    def send_remove_pusher(self, app_id, push_key, user_id):
-        """Poke the master to remove a pusher for a user
-        """
-        cmd = RemovePusherCommand(app_id, push_key, user_id)
-        self.send_command(cmd)
-
-    def send_invalidate_cache(self, cache_func, keys):
-        """Poke the master to invalidate a cache.
-        """
-        cmd = InvalidateCacheCommand(cache_func.__name__, keys)
-        self.send_command(cmd)
-
-    def send_user_ip(self, user_id, access_token, ip, user_agent, device_id, last_seen):
-        """Tell the master that the user made a request.
-        """
-        cmd = UserIpCommand(user_id, access_token, ip, user_agent, device_id, last_seen)
-        self.send_command(cmd)
-
-    def send_remote_server_up(self, server: str):
-        self.send_command(RemoteServerUpCommand(server))
-
-    def await_sync(self, data):
-        """Returns a deferred that is resolved when we receive a SYNC command
-        with given data.
-
-        [Not currently] used by tests.
-        """
-        return self.awaiting_syncs.setdefault(data, defer.Deferred())
-
-    def update_connection(self, connection):
-        """Called when a connection has been established (or lost with None).
-        """
-        self.connection = connection
-        if connection:
-            for cmd in self.pending_commands:
-                connection.send_command(cmd)
-            self.pending_commands = []
-
-    def finished_connecting(self):
-        """Called when we have successfully subscribed and caught up to all
-        streams we're interested in.
-        """
-        logger.info("Finished connecting to server")
+    async def on_position(self, stream_name: str, token: int):
+        self.store.process_replication_rows(stream_name, token, [])
 
-        # We don't reset the delay any earlier as otherwise if there is a
-        # problem during start up we'll end up tight looping connecting to the
-        # server.
-        if self.factory:
-            self.factory.resetDelay()
+    def on_remote_server_up(self, server: str):
+        """Called when get a new REMOTE_SERVER_UP command."""