Merge pull request #6675 from matrix-org/rav/die_sqlite37_die_die_die

Refuse to start if sqlite is older than 3.11.0

6 files changed, 47 insertions, 41 deletions

diff --git a/INSTALL.md b/INSTALL.md
index 9da2e3c734..d25fcf0753 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -133,6 +133,11 @@ sudo yum install libtiff-devel libjpeg-devel libzip-devel freetype-devel \
 sudo yum groupinstall "Development Tools"
 ```
 
+Note that Synapse does not support versions of SQLite before 3.11, and CentOS 7
+uses SQLite 3.7. You may be able to work around this by installing a more
+recent SQLite version, but it is recommended that you instead use a Postgres
+database: see [docs/postgres.md](docs/postgres.md).
+
 #### macOS
 
 Installing prerequisites on macOS:
diff --git a/changelog.d/6675.removal b/changelog.d/6675.removal
new file mode 100644
index 0000000000..95df9a2d83
--- /dev/null
+++ b/changelog.d/6675.removal
@@ -0,0 +1 @@
+Synapse no longer supports versions of SQLite before 3.11, and will refuse to start when configured to use an older version. Administrators are recommended to migrate their database to Postgres (see instructions [here](docs/postgres.md)).
diff --git a/scripts/synapse_port_db b/scripts/synapse_port_db
index cb77314f1e..f135c8bc54 100755
--- a/scripts/synapse_port_db
+++ b/scripts/synapse_port_db
@@ -447,20 +447,15 @@ class Porter(object):
             else:
                 return
 
-    def setup_db(self, db_config: DatabaseConnectionConfig, engine):
-        db_conn = make_conn(db_config, engine)
-        prepare_database(db_conn, engine, config=None)
-
-        db_conn.commit()
-
-        return db_conn
-
-    @defer.inlineCallbacks
-    def build_db_store(self, db_config: DatabaseConnectionConfig):
+    def build_db_store(
+        self, db_config: DatabaseConnectionConfig, allow_outdated_version: bool = False,
+    ):
         """Builds and returns a database store using the provided configuration.
 
         Args:
-            config: The database configuration
+            db_config: The database configuration
+            allow_outdated_version: True to suppress errors about the database server
+                version being too old to run a complete synapse
 
         Returns:
             The built Store object.
@@ -468,16 +463,16 @@ class Porter(object):
         self.progress.set_state("Preparing %s" % db_config.config["name"])
 
         engine = create_engine(db_config.config)
-        conn = self.setup_db(db_config, engine)
 
         hs = MockHomeserver(self.hs_config)
 
-        store = Store(Database(hs, db_config, engine), conn, hs)
-
-        yield store.db.runInteraction(
-            "%s_engine.check_database" % db_config.config["name"],
-            engine.check_database,
-        )
+        with make_conn(db_config, engine) as db_conn:
+            engine.check_database(
+                db_conn, allow_outdated_version=allow_outdated_version
+            )
+            prepare_database(db_conn, engine, config=None)
+            store = Store(Database(hs, db_config, engine), db_conn, hs)
+            db_conn.commit()
 
         return store
 
@@ -502,8 +497,10 @@ class Porter(object):
     @defer.inlineCallbacks
     def run(self):
         try:
-            self.sqlite_store = yield self.build_db_store(
-                DatabaseConnectionConfig("master-sqlite", self.sqlite_config)
+            # we allow people to port away from outdated versions of sqlite.
+            self.sqlite_store = self.build_db_store(
+                DatabaseConnectionConfig("master-sqlite", self.sqlite_config),
+                allow_outdated_version=True,
             )
 
             # Check if all background updates are done, abort if not.
@@ -518,7 +515,7 @@ class Porter(object):
                 )
                 defer.returnValue(None)
 
-            self.postgres_store = yield self.build_db_store(
+            self.postgres_store = self.build_db_store(
                 self.hs_config.get_single_database()
             )
 
diff --git a/synapse/storage/data_stores/__init__.py b/synapse/storage/data_stores/__init__.py
index 092e803799..e1d03429ca 100644
--- a/synapse/storage/data_stores/__init__.py
+++ b/synapse/storage/data_stores/__init__.py
@@ -47,7 +47,7 @@ class DataStores(object):
             with make_conn(database_config, engine) as db_conn:
                 logger.info("Preparing database %r...", db_name)
 
-                engine.check_database(db_conn.cursor())
+                engine.check_database(db_conn)
                 prepare_database(
                     db_conn, engine, hs.config, data_stores=database_config.data_stores,
                 )
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index b7c4eda338..c84cb452b0 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -32,20 +32,7 @@ class PostgresEngine(object):
         self.synchronous_commit = database_config.get("synchronous_commit", True)
         self._version = None  # unknown as yet
 
-    def check_database(self, txn):
-        txn.execute("SHOW SERVER_ENCODING")
-        rows = txn.fetchall()
-        if rows and rows[0][0] != "UTF8":
-            raise IncorrectDatabaseSetup(
-                "Database has incorrect encoding: '%s' instead of 'UTF8'\n"
-                "See docs/postgres.rst for more information." % (rows[0][0],)
-            )
-
-    def convert_param_style(self, sql):
-        return sql.replace("?", "%s")
-
-    def on_new_connection(self, db_conn):
-
+    def check_database(self, db_conn, allow_outdated_version: bool = False):
         # Get the version of PostgreSQL that we're using. As per the psycopg2
         # docs: The number is formed by converting the major, minor, and
         # revision numbers into two-decimal-digit numbers and appending them
@@ -53,9 +40,22 @@ class PostgresEngine(object):
         self._version = db_conn.server_version
 
         # Are we on a supported PostgreSQL version?
-        if self._version < 90500:
+        if not allow_outdated_version and self._version < 90500:
             raise RuntimeError("Synapse requires PostgreSQL 9.5+ or above.")
 
+        with db_conn.cursor() as txn:
+            txn.execute("SHOW SERVER_ENCODING")
+            rows = txn.fetchall()
+            if rows and rows[0][0] != "UTF8":
+                raise IncorrectDatabaseSetup(
+                    "Database has incorrect encoding: '%s' instead of 'UTF8'\n"
+                    "See docs/postgres.rst for more information." % (rows[0][0],)
+                )
+
+    def convert_param_style(self, sql):
+        return sql.replace("?", "%s")
+
+    def on_new_connection(self, db_conn):
         db_conn.set_isolation_level(
             self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ
         )
@@ -119,8 +119,8 @@ class PostgresEngine(object):
         Returns:
             string
         """
-        # note that this is a bit of a hack because it relies on on_new_connection
-        # having been called at least once. Still, that should be a safe bet here.
+        # note that this is a bit of a hack because it relies on check_database
+        # having been called. Still, that should be a safe bet here.
         numver = self._version
         assert numver is not None
 
diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py
index df039a072d..cbf52f5191 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -53,8 +53,11 @@ class Sqlite3Engine(object):
         """
         return False
 
-    def check_database(self, txn):
-        pass
+    def check_database(self, db_conn, allow_outdated_version: bool = False):
+        if not allow_outdated_version:
+            version = self.module.sqlite_version_info
+            if version < (3, 11, 0):
+                raise RuntimeError("Synapse requires sqlite 3.11 or above.")
 
     def convert_param_style(self, sql):
         return sql