diff options
Diffstat (limited to 'synapse/util/retryutils.py')
| -rw-r--r-- | synapse/util/retryutils.py | 50 |
1 files changed, 42 insertions, 8 deletions
diff --git a/synapse/util/retryutils.py b/synapse/util/retryutils.py index 153ef001ad..4e93f69d3a 100644 --- a/synapse/util/retryutils.py +++ b/synapse/util/retryutils.py @@ -12,7 +12,7 @@ # 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. - +import synapse.util.logcontext from twisted.internet import defer from synapse.api.errors import CodeMessageException @@ -26,6 +26,18 @@ logger = logging.getLogger(__name__) class NotRetryingDestination(Exception): def __init__(self, retry_last_ts, retry_interval, destination): + """Raised by the limiter (and federation client) to indicate that we are + are deliberately not attempting to contact a given server. + + Args: + retry_last_ts (int): the unix ts in milliseconds of our last attempt + to contact the server. 0 indicates that the last attempt was + successful or that we've never actually attempted to connect. + retry_interval (int): the time in milliseconds to wait until the next + attempt. + destination (str): the domain in question + """ + msg = "Not retrying server %s." % (destination,) super(NotRetryingDestination, self).__init__(msg) @@ -35,7 +47,8 @@ class NotRetryingDestination(Exception): @defer.inlineCallbacks -def get_retry_limiter(destination, clock, store, **kwargs): +def get_retry_limiter(destination, clock, store, ignore_backoff=False, + **kwargs): """For a given destination check if we have previously failed to send a request there and are waiting before retrying the destination. If we are not ready to retry the destination, this will raise a @@ -43,6 +56,14 @@ def get_retry_limiter(destination, clock, store, **kwargs): that will mark the destination as down if an exception is thrown (excluding CodeMessageException with code < 500) + Args: + destination (str): name of homeserver + clock (synapse.util.clock): timing source + store (synapse.storage.transactions.TransactionStore): datastore + ignore_backoff (bool): true to ignore the historical backoff data and + try the request anyway. We will still update the next + retry_interval on success/failure. + Example usage: try: @@ -66,7 +87,7 @@ def get_retry_limiter(destination, clock, store, **kwargs): now = int(clock.time_msec()) - if retry_last_ts + retry_interval > now: + if not ignore_backoff and retry_last_ts + retry_interval > now: raise NotRetryingDestination( retry_last_ts=retry_last_ts, retry_interval=retry_interval, @@ -124,7 +145,13 @@ class RetryDestinationLimiter(object): def __exit__(self, exc_type, exc_val, exc_tb): valid_err_code = False - if exc_type is not None and issubclass(exc_type, CodeMessageException): + if exc_type is None: + valid_err_code = True + elif not issubclass(exc_type, Exception): + # avoid treating exceptions which don't derive from Exception as + # failures; this is mostly so as not to catch defer._DefGen. + valid_err_code = True + elif issubclass(exc_type, CodeMessageException): # Some error codes are perfectly fine for some APIs, whereas other # APIs may expect to never received e.g. a 404. It's important to # handle 404 as some remote servers will return a 404 when the HS @@ -142,11 +169,13 @@ class RetryDestinationLimiter(object): else: valid_err_code = False - if exc_type is None or valid_err_code: + if valid_err_code: # We connected successfully. if not self.retry_interval: return + logger.debug("Connection to %s was successful; clearing backoff", + self.destination) retry_last_ts = 0 self.retry_interval = 0 else: @@ -160,6 +189,10 @@ class RetryDestinationLimiter(object): else: self.retry_interval = self.min_retry_interval + logger.debug( + "Connection to %s was unsuccessful (%s(%s)); backoff now %i", + self.destination, exc_type, exc_val, self.retry_interval + ) retry_last_ts = int(self.clock.time_msec()) @defer.inlineCallbacks @@ -168,9 +201,10 @@ class RetryDestinationLimiter(object): yield self.store.set_destination_retry_timings( self.destination, retry_last_ts, self.retry_interval ) - except: + except Exception: logger.exception( - "Failed to store set_destination_retry_timings", + "Failed to store destination_retry_timings", ) - store_retry_timings() + # we deliberately do this in the background. + synapse.util.logcontext.run_in_background(store_retry_timings) |