Make retrying requests on DNS failures configurable, and turn off retrying only in directory.get_association

This commit is contained in:
Kegan Dougal 2014-09-03 14:26:35 +01:00
parent c06d07a276
commit 7fc84c7019
3 changed files with 29 additions and 8 deletions

View file

@ -18,6 +18,7 @@ from twisted.internet import defer
from ._base import BaseHandler
from synapse.api.errors import SynapseError
from synapse.http.client import HttpClient
import logging
@ -68,7 +69,10 @@ class DirectoryHandler(BaseHandler):
result = yield self.federation.make_query(
destination=room_alias.domain,
query_type="directory",
args={"room_alias": room_alias.to_string()},
args={
"room_alias": room_alias.to_string(),
HttpClient.RETRY_DNS_LOOKUP_FAILURES: False
}
)
if result and "room_id" in result and "servers" in result:

View file

@ -44,6 +44,7 @@ _destination_mappings = {
class HttpClient(object):
""" Interface for talking json over http
"""
RETRY_DNS_LOOKUP_FAILURES = "__retry_dns"
def put_json(self, destination, path, data):
""" Sends the specifed json data using PUT
@ -143,13 +144,23 @@ class TwistedHttpClient(HttpClient):
destination = _destination_mappings[destination]
logger.debug("get_json args: %s", args)
retry_on_dns_fail = True
if HttpClient.RETRY_DNS_LOOKUP_FAILURES in args:
# FIXME: This isn't ideal, but the interface exposed in get_json
# isn't comprehensive enough to give caller's any control over
# their connection mechanics.
retry_on_dns_fail = args.pop(HttpClient.RETRY_DNS_LOOKUP_FAILURES)
query_bytes = urllib.urlencode(args, True)
logger.debug("Query bytes: %s Retry DNS: %s", args, retry_on_dns_fail)
response = yield self._create_request(
destination.encode("ascii"),
"GET",
path.encode("ascii"),
query_bytes=query_bytes
query_bytes=query_bytes,
retry_on_dns_fail=retry_on_dns_fail
)
body = yield readBody(response)
@ -158,7 +169,8 @@ class TwistedHttpClient(HttpClient):
@defer.inlineCallbacks
def _create_request(self, destination, method, path_bytes, param_bytes=b"",
query_bytes=b"", producer=None, headers_dict={}):
query_bytes=b"", producer=None, headers_dict={},
retry_on_dns_fail=True):
""" Creates and sends a request to the given url
"""
headers_dict[b"User-Agent"] = [b"Synapse"]
@ -199,11 +211,12 @@ class TwistedHttpClient(HttpClient):
logger.debug("Got response to %s", method)
break
except DNSLookupError as dns:
logger.warn("DNS Lookup failed to %s with %s", destination,
dns)
raise SynapseError(400, "Domain specified not found.")
except Exception as e:
if not retry_on_dns_fail and isinstance(e, DNSLookupError):
logger.warn("DNS Lookup failed to %s with %s", destination,
e)
raise SynapseError(400, "Domain specified not found.")
logger.exception("Got error in _create_request")
_print_ex(e)

View file

@ -21,6 +21,7 @@ from mock import Mock
import logging
from synapse.server import HomeServer
from synapse.http.client import HttpClient
from synapse.handlers.directory import DirectoryHandler
from synapse.storage.directory import RoomAliasMapping
@ -92,7 +93,10 @@ class DirectoryTestCase(unittest.TestCase):
self.mock_federation.make_query.assert_called_with(
destination="remote",
query_type="directory",
args={"room_alias": "#another:remote"}
args={
"room_alias": "#another:remote",
HttpClient.RETRY_DNS_LOOKUP_FAILURES: False
}
)
@defer.inlineCallbacks