Remove slaved id tracker (#14376)

This matches the multi instance writer ID generator class which can
both handle advancing the current token over replication and by calling
the database.

changelog.d/14376.misc

@@ -0,0 +1 @@
+Remove old stream ID tracking code. Contributed by Nick @Beeper (@fizzadar).

synapse/replication/slave/__init__.py

@@ -1,13 +0,0 @@
-# Copyright 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.

synapse/replication/slave/storage/__init__.py

@@ -1,13 +0,0 @@
-# Copyright 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.

synapse/replication/slave/storage/_slaved_id_tracker.py

@@ -1,50 +0,0 @@
-# Copyright 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.
-from typing import List, Optional, Tuple
-
-from synapse.storage.database import LoggingDatabaseConnection
-from synapse.storage.util.id_generators import AbstractStreamIdTracker, _load_current_id
-
-
-class SlavedIdTracker(AbstractStreamIdTracker):
-    """Tracks the "current" stream ID of a stream with a single writer.
-
-    See `AbstractStreamIdTracker` for more details.
-
-    Note that this class does not work correctly when there are multiple
-    writers.
-    """
-
-    def __init__(
-        self,
-        db_conn: LoggingDatabaseConnection,
-        table: str,
-        column: str,
-        extra_tables: Optional[List[Tuple[str, str]]] = None,
-        step: int = 1,
-    ):
-        self.step = step
-        self._current = _load_current_id(db_conn, table, column, step)
-        if extra_tables:
-            for table, column in extra_tables:
-                self.advance(None, _load_current_id(db_conn, table, column))
-
-    def advance(self, instance_name: Optional[str], new_id: int) -> None:
-        self._current = (max if self.step > 0 else min)(self._current, new_id)
-
-    def get_current_token(self) -> int:
-        return self._current
-
-    def get_current_token_for_writer(self, instance_name: str) -> int:
-        return self.get_current_token()

synapse/storage/databases/main/account_data.py

@@ -27,7 +27,6 @@ from typing import (
 )
 
 from synapse.api.constants import AccountDataTypes
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams import AccountDataStream, TagAccountDataStream
 from synapse.storage._base import db_to_json
 from synapse.storage.database import (
@@ -68,12 +67,11 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
         # to write account data. A value of `True` implies that `_account_data_id_gen`
         # is an `AbstractStreamIdGenerator` and not just a tracker.
         self._account_data_id_gen: AbstractStreamIdTracker
+        self._can_write_to_account_data = (
+            self._instance_name in hs.config.worker.writers.account_data
+        )
 
         if isinstance(database.engine, PostgresEngine):
-            self._can_write_to_account_data = (
-                self._instance_name in hs.config.worker.writers.account_data
-            )
-
             self._account_data_id_gen = MultiWriterIdGenerator(
                 db_conn=db_conn,
                 db=database,
@@ -95,21 +93,13 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
             # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
             # updated over replication. (Multiple writers are not supported for
             # SQLite).
-            if self._instance_name in hs.config.worker.writers.account_data:
+            self._account_data_id_gen = StreamIdGenerator(
-                self._can_write_to_account_data = True
+                db_conn,
-                self._account_data_id_gen = StreamIdGenerator(
+                "room_account_data",
-                    db_conn,
+                "stream_id",
-                    "room_account_data",
+                extra_tables=[("room_tags_revisions", "stream_id")],
-                    "stream_id",
+                is_writer=self._instance_name in hs.config.worker.writers.account_data,
-                    extra_tables=[("room_tags_revisions", "stream_id")],
+            )
-                )
-            else:
-                self._account_data_id_gen = SlavedIdTracker(
-                    db_conn,
-                    "room_account_data",
-                    "stream_id",
-                    extra_tables=[("room_tags_revisions", "stream_id")],
-                )
 
         account_max = self.get_max_account_data_stream_id()
         self._account_data_stream_cache = StreamChangeCache(

synapse/storage/databases/main/devices.py

@@ -38,7 +38,6 @@ from synapse.logging.opentracing import (
     whitelisted_homeserver,
 )
 from synapse.metrics.background_process_metrics import wrap_as_background_process
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams._base import DeviceListsStream, UserSignatureStream
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
 from synapse.storage.database import (
@@ -86,28 +85,19 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
     ):
         super().__init__(database, db_conn, hs)
 
-        if hs.config.worker.worker_app is None:
+        # In the worker store this is an ID tracker which we overwrite in the non-worker
-            self._device_list_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
+        # class below that is used on the main process.
-                db_conn,
+        self._device_list_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
-                "device_lists_stream",
+            db_conn,
-                "stream_id",
+            "device_lists_stream",
-                extra_tables=[
+            "stream_id",
-                    ("user_signature_stream", "stream_id"),
+            extra_tables=[
-                    ("device_lists_outbound_pokes", "stream_id"),
+                ("user_signature_stream", "stream_id"),
-                    ("device_lists_changes_in_room", "stream_id"),
+                ("device_lists_outbound_pokes", "stream_id"),
-                ],
+                ("device_lists_changes_in_room", "stream_id"),
-            )
+            ],
-        else:
+            is_writer=hs.config.worker.worker_app is None,
-            self._device_list_id_gen = SlavedIdTracker(
+        )
-                db_conn,
-                "device_lists_stream",
-                "stream_id",
-                extra_tables=[
-                    ("user_signature_stream", "stream_id"),
-                    ("device_lists_outbound_pokes", "stream_id"),
-                    ("device_lists_changes_in_room", "stream_id"),
-                ],
-            )
 
         # Type-ignore: _device_list_id_gen is mixed in from either DataStore (as a
         # StreamIdGenerator) or SlavedDataStore (as a SlavedIdTracker).

synapse/storage/databases/main/events_worker.py

@@ -59,7 +59,6 @@ from synapse.metrics.background_process_metrics import (
     run_as_background_process,
     wrap_as_background_process,
 )
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams import BackfillStream
 from synapse.replication.tcp.streams.events import EventsStream
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
@@ -213,26 +212,20 @@ class EventsWorkerStore(SQLBaseStore):
             # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
             # updated over replication. (Multiple writers are not supported for
             # SQLite).
-            if hs.get_instance_name() in hs.config.worker.writers.events:
+            self._stream_id_gen = StreamIdGenerator(
-                self._stream_id_gen = StreamIdGenerator(
+                db_conn,
-                    db_conn,
+                "events",
-                    "events",
+                "stream_ordering",
-                    "stream_ordering",
+                is_writer=hs.get_instance_name() in hs.config.worker.writers.events,
-                )
+            )
-                self._backfill_id_gen = StreamIdGenerator(
+            self._backfill_id_gen = StreamIdGenerator(
-                    db_conn,
+                db_conn,
-                    "events",
+                "events",
-                    "stream_ordering",
+                "stream_ordering",
-                    step=-1,
+                step=-1,
-                    extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
+                extra_tables=[("ex_outlier_stream", "event_stream_ordering")],
-                )
+                is_writer=hs.get_instance_name() in hs.config.worker.writers.events,
-            else:
+            )
-                self._stream_id_gen = SlavedIdTracker(
-                    db_conn, "events", "stream_ordering"
-                )
-                self._backfill_id_gen = SlavedIdTracker(
-                    db_conn, "events", "stream_ordering", step=-1
-                )
 
         events_max = self._stream_id_gen.get_current_token()
         curr_state_delta_prefill, min_curr_state_delta_id = self.db_pool.get_cache_dict(

synapse/storage/databases/main/push_rule.py

@@ -30,7 +30,6 @@ from typing import (
 
 from synapse.api.errors import StoreError
 from synapse.config.homeserver import ExperimentalConfig
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams import PushRulesStream
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import (
@@ -111,14 +110,14 @@ class PushRulesWorkerStore(
     ):
         super().__init__(database, db_conn, hs)
 
-        if hs.config.worker.worker_app is None:
+        # In the worker store this is an ID tracker which we overwrite in the non-worker
-            self._push_rules_stream_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
+        # class below that is used on the main process.
-                db_conn, "push_rules_stream", "stream_id"
+        self._push_rules_stream_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
-            )
+            db_conn,
-        else:
+            "push_rules_stream",
-            self._push_rules_stream_id_gen = SlavedIdTracker(
+            "stream_id",
-                db_conn, "push_rules_stream", "stream_id"
+            is_writer=hs.config.worker.worker_app is None,
-            )
+        )
 
         push_rules_prefill, push_rules_id = self.db_pool.get_cache_dict(
             db_conn,

synapse/storage/databases/main/pusher.py

@@ -27,7 +27,6 @@ from typing import (
 )
 
 from synapse.push import PusherConfig, ThrottleParams
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams import PushersStream
 from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.storage.database import (
@@ -59,20 +58,15 @@ class PusherWorkerStore(SQLBaseStore):
     ):
         super().__init__(database, db_conn, hs)
 
-        if hs.config.worker.worker_app is None:
+        # In the worker store this is an ID tracker which we overwrite in the non-worker
-            self._pushers_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
+        # class below that is used on the main process.
-                db_conn,
+        self._pushers_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
-                "pushers",
+            db_conn,
-                "id",
+            "pushers",
-                extra_tables=[("deleted_pushers", "stream_id")],
+            "id",
-            )
+            extra_tables=[("deleted_pushers", "stream_id")],
-        else:
+            is_writer=hs.config.worker.worker_app is None,
-            self._pushers_id_gen = SlavedIdTracker(
+        )
-                db_conn,
-                "pushers",
-                "id",
-                extra_tables=[("deleted_pushers", "stream_id")],
-            )
 
         self.db_pool.updates.register_background_update_handler(
             "remove_deactivated_pushers",

synapse/storage/databases/main/receipts.py

@@ -27,7 +27,6 @@ from typing import (
 )
 
 from synapse.api.constants import EduTypes
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
 from synapse.replication.tcp.streams import ReceiptsStream
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
 from synapse.storage.database import (
@@ -61,6 +60,9 @@ class ReceiptsWorkerStore(SQLBaseStore):
         hs: "HomeServer",
     ):
         self._instance_name = hs.get_instance_name()
+
+        # In the worker store this is an ID tracker which we overwrite in the non-worker
+        # class below that is used on the main process.
         self._receipts_id_gen: AbstractStreamIdTracker
 
         if isinstance(database.engine, PostgresEngine):
@@ -87,14 +89,12 @@ class ReceiptsWorkerStore(SQLBaseStore):
             # `StreamIdGenerator`, otherwise we use `SlavedIdTracker` which gets
             # updated over replication. (Multiple writers are not supported for
             # SQLite).
-            if hs.get_instance_name() in hs.config.worker.writers.receipts:
+            self._receipts_id_gen = StreamIdGenerator(
-                self._receipts_id_gen = StreamIdGenerator(
+                db_conn,
-                    db_conn, "receipts_linearized", "stream_id"
+                "receipts_linearized",
-                )
+                "stream_id",
-            else:
+                is_writer=hs.get_instance_name() in hs.config.worker.writers.receipts,
-                self._receipts_id_gen = SlavedIdTracker(
+            )
-                    db_conn, "receipts_linearized", "stream_id"
-                )
 
         super().__init__(database, db_conn, hs)
 

synapse/storage/util/id_generators.py

@@ -186,11 +186,13 @@ class StreamIdGenerator(AbstractStreamIdGenerator):
         column: str,
         extra_tables: Iterable[Tuple[str, str]] = (),
         step: int = 1,
+        is_writer: bool = True,
     ) -> None:
         assert step != 0
         self._lock = threading.Lock()
         self._step: int = step
         self._current: int = _load_current_id(db_conn, table, column, step)
+        self._is_writer = is_writer
         for table, column in extra_tables:
             self._current = (max if step > 0 else min)(
                 self._current, _load_current_id(db_conn, table, column, step)
@@ -204,9 +206,11 @@ class StreamIdGenerator(AbstractStreamIdGenerator):
         self._unfinished_ids: OrderedDict[int, int] = OrderedDict()
 
     def advance(self, instance_name: str, new_id: int) -> None:
-        # `StreamIdGenerator` should only be used when there is a single writer,
+        # Advance should never be called on a writer instance, only over replication
-        # so replication should never happen.
+        if self._is_writer:
-        raise Exception("Replication is not supported by StreamIdGenerator")
+            raise Exception("Replication is not supported by writer StreamIdGenerator")
+
+        self._current = (max if self._step > 0 else min)(self._current, new_id)
 
     def get_next(self) -> AsyncContextManager[int]:
         with self._lock:
@@ -249,6 +253,9 @@ class StreamIdGenerator(AbstractStreamIdGenerator):
         return _AsyncCtxManagerWrapper(manager())
 
     def get_current_token(self) -> int:
+        if self._is_writer:
+            return self._current
+
         with self._lock:
             if self._unfinished_ids:
                 return next(iter(self._unfinished_ids)) - self._step