another idea

edb/server/pgcon/pgcon.pyx

@@ -699,7 +699,7 @@ cdef class PGConnection:
     async def signal_sysevent(self, event, **kwargs):
         if self.tenant.get_backend_runtime_params().has_create_database:
             assert defines.EDGEDB_SYSTEM_DB in self.dbname
-        print("SIGNAL", event, self.tenant._signal_ctr)
+        # print("SIGNAL", event, self.tenant._signal_ctr)
         event = json.dumps({
             'event': event,
             'server_id': self.server._server_id,
@@ -713,8 +713,12 @@ cdef class PGConnection:
                 {pg_ql(event)}
             )
         """.encode()
+
+        num = self.tenant._signals_received
         await self.sql_execute(query)
-        print('DONE SIGNAL')
+        assert self.tenant._signals_received == num + 1, (
+            self.tenant._signals_received, num + 1, event)
+        # print('DONE SIGNAL')
 
     async def sync(self):
         if self.waiting_for_sync:
@@ -2892,8 +2896,9 @@ cdef class PGConnection:
                 event = event_data.get('event')
 
                 server_id = event_data.get('server_id')
-                print("GOT   ", event, event_data.get('num'))
+                # print("GOT   ", event, event_data.get('num'))
                 if server_id == self.server._server_id:
+                    self.tenant._signals_received += 1
                     # We should only react to notifications sent
                     # by other edgedb servers. Reacting to events
                     # generated by this server must be implemented

edb/server/tenant.py

@@ -130,6 +130,7 @@ def __init__(
     ):
         self._pending_cache_changes = 0
         self._signal_ctr = 0
+        self._signals_received = 0
 
         self._cluster = cluster
         self._tenant_id = self.get_backend_runtime_params().tenant_id