From e55a9b3e41e73f34fda781b9374935c4623f7ea9 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 10 Jul 2023 16:24:42 +0100 Subject: Fix downgrading to previous version of Synapse (#15907) We do this by marking the constraint as deferrable. --- synapse/storage/background_updates.py | 7 ++++++- synapse/storage/databases/main/event_federation.py | 4 +++- .../schema/main/delta/78/03event_extremities_constraints.py | 10 ++++++++-- 3 files changed, 17 insertions(+), 4 deletions(-) (limited to 'synapse') diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py index 5dce0a0159..2d5ddc3e7b 100644 --- a/synapse/storage/background_updates.py +++ b/synapse/storage/background_updates.py @@ -80,10 +80,14 @@ class ForeignKeyConstraint(Constraint): Attributes: referenced_table: The "parent" table name. columns: The list of mappings of columns from table to referenced table + deferred: Whether to defer checking of the constraint to the end of the + transaction. This is useful for e.g. backwards compatibility where + an older version inserted data in the wrong order. """ referenced_table: str columns: Sequence[Tuple[str, str]] + deferred: bool def make_check_clause(self, table: str) -> str: join_clause = " AND ".join( @@ -94,7 +98,8 @@ class ForeignKeyConstraint(Constraint): def make_constraint_clause_postgres(self) -> str: column1_list = ", ".join(col1 for col1, col2 in self.columns) column2_list = ", ".join(col2 for col1, col2 in self.columns) - return f"FOREIGN KEY ({column1_list}) REFERENCES {self.referenced_table} ({column2_list})" + defer_clause = " DEFERRABLE INITIALLY DEFERRED" if self.deferred else "" + return f"FOREIGN KEY ({column1_list}) REFERENCES {self.referenced_table} ({column2_list}) {defer_clause}" @attr.s(auto_attribs=True) diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py index dabe603c8c..b2cda52ce5 100644 --- a/synapse/storage/databases/main/event_federation.py +++ b/synapse/storage/databases/main/event_federation.py @@ -146,7 +146,9 @@ class EventFederationWorkerStore(SignatureWorkerStore, EventsWorkerStore, SQLBas update_name="event_forward_extremities_event_id_foreign_key_constraint_update", table="event_forward_extremities", constraint_name="event_forward_extremities_event_id", - constraint=ForeignKeyConstraint("events", [("event_id", "event_id")]), + constraint=ForeignKeyConstraint( + "events", [("event_id", "event_id")], deferred=True + ), unique_columns=("event_id", "room_id"), ) diff --git a/synapse/storage/schema/main/delta/78/03event_extremities_constraints.py b/synapse/storage/schema/main/delta/78/03event_extremities_constraints.py index f12e2a8f3e..bf8c57dbe8 100644 --- a/synapse/storage/schema/main/delta/78/03event_extremities_constraints.py +++ b/synapse/storage/schema/main/delta/78/03event_extremities_constraints.py @@ -28,19 +28,25 @@ FORWARD_EXTREMITIES_TABLE_SCHEMA = """ event_id TEXT NOT NULL, room_id TEXT NOT NULL, UNIQUE (event_id, room_id), - CONSTRAINT event_forward_extremities_event_id FOREIGN KEY (event_id) REFERENCES events (event_id) + CONSTRAINT event_forward_extremities_event_id FOREIGN KEY (event_id) REFERENCES events (event_id) DEFERRABLE INITIALLY DEFERRED ) """ def run_create(cur: LoggingTransaction, database_engine: BaseDatabaseEngine) -> None: + # We mark this as a deferred constraint, as the previous version of Synapse + # inserted the event into the forward extremities *before* the events table. + # By marking as deferred we ensure that downgrading to the previous version + # will continue to work. run_validate_constraint_and_delete_rows_schema_delta( cur, ordering=7803, update_name="event_forward_extremities_event_id_foreign_key_constraint_update", table="event_forward_extremities", constraint_name="event_forward_extremities_event_id", - constraint=ForeignKeyConstraint("events", [("event_id", "event_id")]), + constraint=ForeignKeyConstraint( + "events", [("event_id", "event_id")], deferred=True + ), sqlite_table_name="event_forward_extremities2", sqlite_table_schema=FORWARD_EXTREMITIES_TABLE_SCHEMA, ) -- cgit 1.4.1