diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index f4c60e67e3..800f04189f 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -425,6 +425,7 @@ class FederationServer(FederationBase):
" limit: %d, min_depth: %d",
earliest_events, latest_events, limit, min_depth
)
+
missing_events = yield self.handler.on_get_missing_events(
origin, room_id, earliest_events, latest_events, limit, min_depth
)
@@ -567,6 +568,25 @@ class FederationServer(FederationBase):
len(prevs - seen), pdu.room_id, list(prevs - seen)[:5]
)
+ # XXX: we set timeout to 10s to help workaround
+ # https://github.com/matrix-org/synapse/issues/1733.
+ # The reason is to avoid holding the linearizer lock
+ # whilst processing inbound /send transactions, causing
+ # FDs to stack up and block other inbound transactions
+ # which empirically can currently take up to 30 minutes.
+ #
+ # N.B. this explicitly disables retry attempts.
+ #
+ # N.B. this also increases our chances of falling back to
+ # fetching fresh state for the room if the missing event
+ # can't be found, which slightly reduces our security.
+ # it may also increase our DAG extremity count for the room,
+ # causing additional state resolution? See #1760.
+ # However, fetching state doesn't hold the linearizer lock
+ # apparently.
+ #
+ # see https://github.com/matrix-org/synapse/pull/1744
+
missing_events = yield self.get_missing_events(
origin,
pdu.room_id,
@@ -574,6 +594,7 @@ class FederationServer(FederationBase):
latest_events=[pdu],
limit=10,
min_depth=min_depth,
+ timeout=10000,
)
# We want to sort these by depth so we process them and
|
