diff options
Diffstat (limited to 'synapse')
| -rwxr-xr-x | synapse/_scripts/synapse_port_db.py | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py index d3b4887f69..642fd41629 100755 --- a/synapse/_scripts/synapse_port_db.py +++ b/synapse/_scripts/synapse_port_db.py @@ -621,6 +621,25 @@ class Porter: self.postgres_store.db_pool.updates.has_completed_background_updates() ) + @staticmethod + def _is_sqlite_autovacuum_enabled(txn: LoggingTransaction) -> bool: + """ + Returns true if auto_vacuum is enabled in SQLite. + https://www.sqlite.org/pragma.html#pragma_auto_vacuum + + Vacuuming changes the rowids on rows in the database. + Auto-vacuuming is therefore dangerous when used in conjunction with this script. + + Note that the auto_vacuum setting can't be changed without performing + a VACUUM after trying to change the pragma. + """ + txn.execute("PRAGMA auto_vacuum") + row = txn.fetchone() + assert row is not None, "`PRAGMA auto_vacuum` did not give a row." + (autovacuum_setting,) = row + # 0 means off. 1 means full. 2 means incremental. + return autovacuum_setting != 0 + async def run(self) -> None: """Ports the SQLite database to a PostgreSQL database. @@ -637,6 +656,21 @@ class Porter: allow_outdated_version=True, ) + # For safety, ensure auto_vacuums are disabled. + if await self.sqlite_store.db_pool.runInteraction( + "is_sqlite_autovacuum_enabled", self._is_sqlite_autovacuum_enabled + ): + end_error = ( + "auto_vacuum is enabled in the SQLite database." + " (This is not the default configuration.)\n" + " This script relies on rowids being consistent and must not" + " be used if the database could be vacuumed between re-runs.\n" + " To disable auto_vacuum, you need to stop Synapse and run the following SQL:\n" + " PRAGMA auto_vacuum=off;\n" + " VACUUM;" + ) + return + # Check if all background updates are done, abort if not. updates_complete = ( await self.sqlite_store.db_pool.updates.has_completed_background_updates() |