Merge branch 'release-v1.52'

1 files changed, 27 insertions, 6 deletions

diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 30f948a0f7..808342fafb 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -13,8 +13,13 @@
 # limitations under the License.
 
 import logging
+from typing import Mapping, Optional
 
-from synapse.storage.engines._base import BaseDatabaseEngine, IncorrectDatabaseSetup
+from synapse.storage.engines._base import (
+    BaseDatabaseEngine,
+    IncorrectDatabaseSetup,
+    IsolationLevel,
+)
 from synapse.storage.types import Connection
 
 logger = logging.getLogger(__name__)
@@ -34,6 +39,15 @@ class PostgresEngine(BaseDatabaseEngine):
         self.synchronous_commit = database_config.get("synchronous_commit", True)
         self._version = None  # unknown as yet
 
+        self.isolation_level_map: Mapping[int, int] = {
+            IsolationLevel.READ_COMMITTED: self.module.extensions.ISOLATION_LEVEL_READ_COMMITTED,
+            IsolationLevel.REPEATABLE_READ: self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ,
+            IsolationLevel.SERIALIZABLE: self.module.extensions.ISOLATION_LEVEL_SERIALIZABLE,
+        }
+        self.default_isolation_level = (
+            self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ
+        )
+
     @property
     def single_threaded(self) -> bool:
         return False
@@ -46,8 +60,8 @@ class PostgresEngine(BaseDatabaseEngine):
         self._version = db_conn.server_version
 
         # Are we on a supported PostgreSQL version?
-        if not allow_outdated_version and self._version < 90600:
-            raise RuntimeError("Synapse requires PostgreSQL 9.6 or above.")
+        if not allow_outdated_version and self._version < 100000:
+            raise RuntimeError("Synapse requires PostgreSQL 10 or above.")
 
         with db_conn.cursor() as txn:
             txn.execute("SHOW SERVER_ENCODING")
@@ -104,9 +118,7 @@ class PostgresEngine(BaseDatabaseEngine):
         return sql.replace("?", "%s")
 
     def on_new_connection(self, db_conn):
-        db_conn.set_isolation_level(
-            self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ
-        )
+        db_conn.set_isolation_level(self.default_isolation_level)
 
         # Set the bytea output to escape, vs the default of hex
         cursor = db_conn.cursor()
@@ -175,3 +187,12 @@ class PostgresEngine(BaseDatabaseEngine):
 
     def attempt_to_set_autocommit(self, conn: Connection, autocommit: bool):
         return conn.set_session(autocommit=autocommit)  # type: ignore
+
+    def attempt_to_set_isolation_level(
+        self, conn: Connection, isolation_level: Optional[int]
+    ):
+        if isolation_level is None:
+            isolation_level = self.default_isolation_level
+        else:
+            isolation_level = self.isolation_level_map[isolation_level]
+        return conn.set_isolation_level(isolation_level)  # type: ignore