Disable federation when using SQLite by default

changelog.d/5078.feature

@@ -0,0 +1 @@
+Disable federation when using SQLite by default.

docs/sample_config.yaml

@@ -354,6 +354,21 @@ acme:
 ## Database ##
 
 database:
+  # Using SQLite induces a severe degradation in performances,
+  # especially when using federation. SQLite should only be used for
+  # personal testing and production instances should use PostgreSQL
+  # instead. You can find documentation on setting up PostgreSQL with
+  # Synapse here:
+  # https://github.com/matrix-org/synapse/blob/master/docs/postgres.rst
+  #
+  # If you want to use federation with SQLite regardless, you can
+  # uncomment the line below, but be aware that it can make Synapse
+  # very laggy and malfunctioning, especially when joining large
+  # rooms. This option defaults to False when using SQLite and True
+  # otherwise.
+  #
+  #enable_federation = True
+
   # The database engine name
   name: "sqlite3"
   # Arguments to pass to the engine

synapse/config/database.py

@@ -34,13 +34,19 @@ def read_config(self, config):
 
         name = self.database_config.get("name", None)
         if name == "psycopg2":
-            pass
+            self.database_enable_federation = self.database_config.get(
+                "enable_federation", True,
+            )
         elif name == "sqlite3":
             self.database_config.setdefault("args", {}).update({
                 "cp_min": 1,
                 "cp_max": 1,
                 "check_same_thread": False,
             })
+
+            self.database_enable_federation = self.database_config.get(
+                "enable_federation", False,
+            )
         else:
             raise RuntimeError("Unsupported database type '%s'" % (name,))
 
@@ -52,6 +58,21 @@ def default_config(self, data_dir_path, **kwargs):
         ## Database ##
 
         database:
+          # Using SQLite induces a severe degradation in performances,
+          # especially when using federation. SQLite should only be used for
+          # personal testing and production instances should use PostgreSQL
+          # instead. You can find documentation on setting up PostgreSQL with
+          # Synapse here:
+          # https://github.com/matrix-org/synapse/blob/master/docs/postgres.rst
+          #
+          # If you want to use federation with SQLite regardless, you can
+          # uncomment the line below, but be aware that it can make Synapse
+          # very laggy and malfunctioning, especially when joining large
+          # rooms. This option defaults to False when using SQLite and True
+          # otherwise.
+          #
+          #enable_federation = True
+
           # The database engine name
           name: "sqlite3"
           # Arguments to pass to the engine

synapse/federation/transport/server.py

@@ -98,6 +98,7 @@ def __init__(self, hs):
         self.server_name = hs.hostname
         self.store = hs.get_datastore()
         self.federation_domain_whitelist = hs.config.federation_domain_whitelist
+        self.database_enable_federation = hs.config.database_enable_federation
 
     # A method just so we can pass 'self' as the authenticator to the Servlets
     @defer.inlineCallbacks
@@ -130,7 +131,7 @@ def authenticate_request(self, request, content):
         if (
             self.federation_domain_whitelist is not None and
             origin not in self.federation_domain_whitelist
-        ):
+        ) or not self.database_enable_federation:
             raise FederationDeniedError(origin)
 
         if not json_request["signatures"]:

synapse/http/matrixfederationclient.py

@@ -286,7 +286,7 @@ def _send_request(
         if (
             self.hs.config.federation_domain_whitelist is not None and
             request.destination not in self.hs.config.federation_domain_whitelist
-        ):
+        ) or not self.hs.config.database_enable_federation:
             raise FederationDeniedError(request.destination)
 
         limiter = yield synapse.util.retryutils.get_retry_limiter(

synapse/rest/media/v1/media_repository.py

@@ -84,6 +84,7 @@ def __init__(self, hs):
         self.recently_accessed_locals = set()
 
         self.federation_domain_whitelist = hs.config.federation_domain_whitelist
+        self.database_enable_federation = hs.config.database_enable_federation
 
         # List of StorageProviders where we should search for media and
         # potentially upload to.
@@ -234,7 +235,7 @@ def get_remote_media(self, request, server_name, media_id, name):
         if (
             self.federation_domain_whitelist is not None and
             server_name not in self.federation_domain_whitelist
-        ):
+        ) or not self.database_enable_federation:
             raise FederationDeniedError(server_name)
 
         self.mark_recently_accessed(server_name, media_id)
@@ -274,7 +275,7 @@ def get_remote_media_info(self, server_name, media_id):
         if (
             self.federation_domain_whitelist is not None and
             server_name not in self.federation_domain_whitelist
-        ):
+        ) or not self.database_enable_federation:
             raise FederationDeniedError(server_name)
 
         # We linearize here to ensure that we don't try and download remote

tests/utils.py

@@ -186,6 +186,8 @@ def default_config(name):
     # background, which upsets the test runner.
     config.update_user_directory = False
 
+    config.database_enable_federation = True
+
     return config
 
 
@@ -244,7 +246,11 @@ def setup_test_homeserver(
     else:
         config.database_config = {
             "name": "sqlite3",
-            "args": {"database": ":memory:", "cp_min": 1, "cp_max": 1},
+            "args": {
+                "database": ":memory:",
+                "cp_min": 1,
+                "cp_max": 1,
+            },
         }
 
     db_engine = create_engine(config.database_config)