diff options
| -rw-r--r-- | synapse/http/endpoint.py | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py index 241b17f2cb..a97532162f 100644 --- a/synapse/http/endpoint.py +++ b/synapse/http/endpoint.py @@ -354,16 +354,28 @@ def _get_hosts_for_srv_record(dns_client, host): return res[0] - def eb(res): - res.trap(DNSNameError) - return [] + def eb(res, record_type): + if res.check(DNSNameError): + return [] + logger.warn("Error looking up %s for %s: %s", + record_type, host, res, res.value) + return res # no logcontexts here, so we can safely fire these off and gatherResults d1 = dns_client.lookupAddress(host).addCallbacks(cb, eb) d2 = dns_client.lookupIPV6Address(host).addCallbacks(cb, eb) - results = yield defer.gatherResults([d1, d2], consumeErrors=True) + results = yield defer.DeferredList( + [d1, d2], consumeErrors=True) + + # if all of the lookups failed, raise an exception rather than blowing out + # the cache with an empty result. + if results and all(s == defer.FAILURE for (s, _) in results): + defer.returnValue(results[0][1]) + + for (success, result) in results: + if success == defer.FAILURE: + continue - for result in results: for answer in result: if not answer.payload: continue |