diff options
| -rw-r--r-- | synapse/http/federation/srv_resolver.py | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py index bbda0a23f4..110b112e85 100644 --- a/synapse/http/federation/srv_resolver.py +++ b/synapse/http/federation/srv_resolver.py @@ -94,10 +94,18 @@ def _sort_server_list(server_list): results = [] for priority in sorted(priority_map): - servers = priority_map.pop(priority) + servers = priority_map[priority] + # This algorithms follows the algorithm described in RFC2782. + # + # N.B. Weights can be zero, which means that you should pick that server + # last *or* that its the only server in this priority. + + # We sort to ensure zero weighted items are first. + servers.sort(key=lambda s: s.weight) + + total_weight = sum(s.weight for s in servers) while servers: - total_weight = sum(s.weight for s in servers) target_weight = random.randint(0, total_weight) for s in servers: @@ -108,6 +116,7 @@ def _sort_server_list(server_list): results.append(s) servers.remove(s) + total_weight -= s.weight return results |