Federation reader should fail more gracefully on a refused connection

[Terbium-135]

Description

At the moment a stack trace is logged:

2019-11-25 22:34:49,018 - synapse.http.server - 109 - ERROR - PUT-1573 - Failed handle request via 'FederationSendServlet': <SynapseRequest at 0x7f59711748 method='PUT' uri='/_matrix/federation/v1/send/1574214481058' clientproto='HTTP/1.1' site=8011>
Traceback (most recent call last):
  File "/root/syntest/synapse/synapse/http/server.py", line 77, in wrapped_request_handler
    await h(self, request)
  File "/root/syntest/synapse/synapse/http/server.py", line 326, in _async_render
    callback_return = await callback_return
  File "/root/syntest/synapse/synapse/federation/transport/server.py", line 324, in new_func
    origin, content, request.args, *args, **kwargs
  File "/root/syntest/synapse/synapse/federation/transport/server.py", line 407, in on_PUT
    origin, transaction_data
  File "/root/syntest/synapse/synapse/federation/federation_server.py", line 121, in on_incoming_transaction
    origin, transaction, request_time
  File "/root/syntest/synapse/synapse/federation/federation_server.py", line 253, in _handle_incoming_transaction
    await self.received_edu(origin, edu.edu_type, edu.content)
  File "/root/syntest/synapse/synapse/federation/federation_server.py", line 264, in received_edu
    await self.registry.on_edu(edu_type, origin, content)
  File "/root/syntest/synapse/synapse/federation/federation_server.py", line 826, in on_edu
    return await self._send_edu(edu_type=edu_type, origin=origin, content=content)
twisted.internet.error.ConnectionRefusedError: Connection was refused by other side: 111: Connection refused.

Version information

• Homeserver: using matrix-synapse 1.60RC2

[richvdh]

I think this is a refused connection when attempting to talk to the master, so to some extent all bets are off. OTOH we could probably fail a bit more gracefully.

1.60RC2

I think you mean 1.6.0rc2 ;)