diff options
Diffstat (limited to 'synapse/http/endpoint.py')
| -rw-r--r-- | synapse/http/endpoint.py | 50 |
1 files changed, 26 insertions, 24 deletions
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py index 564ae4c10d..87a482650d 100644 --- a/synapse/http/endpoint.py +++ b/synapse/http/endpoint.py @@ -12,7 +12,6 @@ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. - from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS from twisted.internet import defer, reactor from twisted.internet.error import ConnectError @@ -30,7 +29,10 @@ logger = logging.getLogger(__name__) SERVER_CACHE = {} - +# our record of an individual server which can be tried to reach a destination. +# +# "host" is the hostname acquired from the SRV record. Except when there's +# no SRV record, in which case it is the original hostname. _Server = collections.namedtuple( "_Server", "priority weight host port expires" ) @@ -224,9 +226,10 @@ class SRVClientEndpoint(object): return self.default_server else: raise ConnectError( - "Not server available for %s" % self.service_name + "No server available for %s" % self.service_name ) + # look for all servers with the same priority min_priority = self.servers[0].priority weight_indexes = list( (index, server.weight + 1) @@ -236,11 +239,22 @@ class SRVClientEndpoint(object): total_weight = sum(weight for index, weight in weight_indexes) target_weight = random.randint(0, total_weight) - for index, weight in weight_indexes: target_weight -= weight if target_weight <= 0: server = self.servers[index] + # XXX: this looks totally dubious: + # + # (a) we never reuse a server until we have been through + # all of the servers at the same priority, so if the + # weights are A: 100, B:1, we always do ABABAB instead of + # AAAA...AAAB (approximately). + # + # (b) After using all the servers at the lowest priority, + # we move onto the next priority. We should only use the + # second priority if servers at the top priority are + # unreachable. + # del self.servers[index] self.used_servers.append(server) return server @@ -277,7 +291,7 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t if (len(answers) == 1 and answers[0].type == dns.SRV and answers[0].payload - and answers[0].payload.target == dns.Name('.')): + and answers[0].payload.target == dns.Name(b'.')): raise ConnectError("Service %s unavailable" % service_name) for answer in answers: @@ -285,26 +299,14 @@ def resolve_service(service_name, dns_client=client, cache=SERVER_CACHE, clock=t continue payload = answer.payload - host = str(payload.target) - srv_ttl = answer.ttl - - try: - answers, _, _ = yield dns_client.lookupAddress(host) - except DNSNameError: - continue - for answer in answers: - if answer.type == dns.A and answer.payload: - ip = answer.payload.dottedQuad() - host_ttl = min(srv_ttl, answer.ttl) - - servers.append(_Server( - host=ip, - port=int(payload.port), - priority=int(payload.priority), - weight=int(payload.weight), - expires=int(clock.time()) + host_ttl, - )) + servers.append(_Server( + host=str(payload.target), + port=int(payload.port), + priority=int(payload.priority), + weight=int(payload.weight), + expires=int(clock.time()) + answer.ttl, + )) servers.sort() cache[service_name] = list(servers) |