Merge branch 'develop' of github.com:matrix-org/synapse into timeout-federation-requests

1 files changed, 11 insertions, 910 deletions

diff --git a/synapse/federation/replication.py b/synapse/federation/replication.py
index a4c29b484b..e442c6c5d5 100644
--- a/synapse/federation/replication.py
+++ b/synapse/federation/replication.py
@@ -17,23 +17,20 @@
 a given transport.
 """
 
-from twisted.internet import defer
+from .federation_client import FederationClient
+from .federation_server import FederationServer
 
-from .units import Transaction, Edu
+from .transaction_queue import TransactionQueue
 
 from .persistence import TransactionActions
 
-from synapse.util.logutils import log_function
-from synapse.util.logcontext import PreserveLoggingContext
-from synapse.events import FrozenEvent
-
 import logging
 
 
 logger = logging.getLogger(__name__)
 
 
-class ReplicationLayer(object):
+class ReplicationLayer(FederationClient, FederationServer):
     """This layer is responsible for replicating with remote home servers over
     the given transport. I.e., does the sending and receiving of PDUs to
     remote home servers.
@@ -54,922 +51,26 @@ class ReplicationLayer(object):
     def __init__(self, hs, transport_layer):
         self.server_name = hs.hostname
 
+        self.keyring = hs.get_keyring()
+
         self.transport_layer = transport_layer
         self.transport_layer.register_received_handler(self)
         self.transport_layer.register_request_handler(self)
 
-        self.store = hs.get_datastore()
-        # self.pdu_actions = PduActions(self.store)
-        self.transaction_actions = TransactionActions(self.store)
+        self.federation_client = self
 
-        self._transaction_queue = _TransactionQueue(
-            hs, self.transaction_actions, transport_layer
-        )
+        self.store = hs.get_datastore()
 
         self.handler = None
         self.edu_handlers = {}
         self.query_handlers = {}
 
-        self._order = 0
-
         self._clock = hs.get_clock()
 
-        self.event_builder_factory = hs.get_event_builder_factory()
-
-    def set_handler(self, handler):
-        """Sets the handler that the replication layer will use to communicate
-        receipt of new PDUs from other home servers. The required methods are
-        documented on :py:class:`.ReplicationHandler`.
-        """
-        self.handler = handler
-
-    def register_edu_handler(self, edu_type, handler):
-        if edu_type in self.edu_handlers:
-            raise KeyError("Already have an EDU handler for %s" % (edu_type,))
-
-        self.edu_handlers[edu_type] = handler
-
-    def register_query_handler(self, query_type, handler):
-        """Sets the handler callable that will be used to handle an incoming
-        federation Query of the given type.
-
-        Args:
-            query_type (str): Category name of the query, which should match
-                the string used by make_query.
-            handler (callable): Invoked to handle incoming queries of this type
-
-        handler is invoked as:
-            result = handler(args)
-
-        where 'args' is a dict mapping strings to strings of the query
-          arguments. It should return a Deferred that will eventually yield an
-          object to encode as JSON.
-        """
-        if query_type in self.query_handlers:
-            raise KeyError(
-                "Already have a Query handler for %s" % (query_type,)
-            )
-
-        self.query_handlers[query_type] = handler
-
-    @log_function
-    def send_pdu(self, pdu, destinations):
-        """Informs the replication layer about a new PDU generated within the
-        home server that should be transmitted to others.
-
-        TODO: Figure out when we should actually resolve the deferred.
-
-        Args:
-            pdu (Pdu): The new Pdu.
-
-        Returns:
-            Deferred: Completes when we have successfully processed the PDU
-            and replicated it to any interested remote home servers.
-        """
-        order = self._order
-        self._order += 1
-
-        logger.debug("[%s] transaction_layer.enqueue_pdu... ", pdu.event_id)
-
-        # TODO, add errback, etc.
-        self._transaction_queue.enqueue_pdu(pdu, destinations, order)
-
-        logger.debug(
-            "[%s] transaction_layer.enqueue_pdu... done",
-            pdu.event_id
-        )
-
-    @log_function
-    def send_edu(self, destination, edu_type, content):
-        edu = Edu(
-            origin=self.server_name,
-            destination=destination,
-            edu_type=edu_type,
-            content=content,
-        )
-
-        # TODO, add errback, etc.
-        self._transaction_queue.enqueue_edu(edu)
-        return defer.succeed(None)
-
-    @log_function
-    def send_failure(self, failure, destination):
-        self._transaction_queue.enqueue_failure(failure, destination)
-        return defer.succeed(None)
-
-    @log_function
-    def make_query(self, destination, query_type, args,
-                   retry_on_dns_fail=True):
-        """Sends a federation Query to a remote homeserver of the given type
-        and arguments.
-
-        Args:
-            destination (str): Domain name of the remote homeserver
-            query_type (str): Category of the query type; should match the
-                handler name used in register_query_handler().
-            args (dict): Mapping of strings to strings containing the details
-                of the query request.
-
-        Returns:
-            a Deferred which will eventually yield a JSON object from the
-            response
-        """
-        return self.transport_layer.make_query(
-            destination, query_type, args, retry_on_dns_fail=retry_on_dns_fail
-        )
-
-    @defer.inlineCallbacks
-    @log_function
-    def backfill(self, dest, context, limit, extremities):
-        """Requests some more historic PDUs for the given context from the
-        given destination server.
-
-        Args:
-            dest (str): The remote home server to ask.
-            context (str): The context to backfill.
-            limit (int): The maximum number of PDUs to return.
-            extremities (list): List of PDU id and origins of the first pdus
-                we have seen from the context
-
-        Returns:
-            Deferred: Results in the received PDUs.
-        """
-        logger.debug("backfill extrem=%s", extremities)
-
-        # If there are no extremeties then we've (probably) reached the start.
-        if not extremities:
-            return
-
-        transaction_data = yield self.transport_layer.backfill(
-            dest, context, extremities, limit)
-
-        logger.debug("backfill transaction_data=%s", repr(transaction_data))
-
-        transaction = Transaction(**transaction_data)
-
-        pdus = [
-            self.event_from_pdu_json(p, outlier=False)
-            for p in transaction.pdus
-        ]
-        for pdu in pdus:
-            yield self._handle_new_pdu(dest, pdu, backfilled=True)
-
-        defer.returnValue(pdus)
-
-    @defer.inlineCallbacks
-    @log_function
-    def get_pdu(self, destination, event_id, outlier=False):
-        """Requests the PDU with given origin and ID from the remote home
-        server.
-
-        This will persist the PDU locally upon receipt.
-
-        Args:
-            destination (str): Which home server to query
-            pdu_origin (str): The home server that originally sent the pdu.
-            event_id (str)
-            outlier (bool): Indicates whether the PDU is an `outlier`, i.e. if
-                it's from an arbitary point in the context as opposed to part
-                of the current block of PDUs. Defaults to `False`
-
-        Returns:
-            Deferred: Results in the requested PDU.
-        """
-
-        transaction_data = yield self.transport_layer.get_event(
-            destination, event_id
-        )
-
-        transaction = Transaction(**transaction_data)
-
-        pdu_list = [
-            self.event_from_pdu_json(p, outlier=outlier)
-            for p in transaction.pdus
-        ]
-
-        pdu = None
-        if pdu_list:
-            pdu = pdu_list[0]
-            yield self._handle_new_pdu(destination, pdu)
-
-        defer.returnValue(pdu)
-
-    @defer.inlineCallbacks
-    @log_function
-    def get_state_for_context(self, destination, context, event_id):
-        """Requests all of the `current` state PDUs for a given context from
-        a remote home server.
-
-        Args:
-            destination (str): The remote homeserver to query for the state.
-            context (str): The context we're interested in.
-            event_id (str): The id of the event we want the state at.
-
-        Returns:
-            Deferred: Results in a list of PDUs.
-        """
-
-        result = yield self.transport_layer.get_context_state(
-            destination,
-            context,
-            event_id=event_id,
-        )
-
-        pdus = [
-            self.event_from_pdu_json(p, outlier=True) for p in result["pdus"]
-        ]
-
-        auth_chain = [
-            self.event_from_pdu_json(p, outlier=True)
-            for p in result.get("auth_chain", [])
-        ]
-
-        defer.returnValue((pdus, auth_chain))
-
-    @defer.inlineCallbacks
-    @log_function
-    def get_event_auth(self, destination, context, event_id):
-        res = yield self.transport_layer.get_event_auth(
-            destination, context, event_id,
-        )
-
-        auth_chain = [
-            self.event_from_pdu_json(p, outlier=True)
-            for p in res["auth_chain"]
-        ]
-
-        auth_chain.sort(key=lambda e: e.depth)
-
-        defer.returnValue(auth_chain)
-
-    @defer.inlineCallbacks
-    @log_function
-    def on_backfill_request(self, origin, context, versions, limit):
-        pdus = yield self.handler.on_backfill_request(
-            origin, context, versions, limit
-        )
-
-        defer.returnValue((200, self._transaction_from_pdus(pdus).get_dict()))
-
-    @defer.inlineCallbacks
-    @log_function
-    def on_incoming_transaction(self, transaction_data):
-        transaction = Transaction(**transaction_data)
-
-        for p in transaction.pdus:
-            if "unsigned" in p:
-                unsigned = p["unsigned"]
-                if "age" in unsigned:
-                    p["age"] = unsigned["age"]
-            if "age" in p:
-                p["age_ts"] = int(self._clock.time_msec()) - int(p["age"])
-                del p["age"]
-
-        pdu_list = [
-            self.event_from_pdu_json(p) for p in transaction.pdus
-        ]
-
-        logger.debug("[%s] Got transaction", transaction.transaction_id)
-
-        response = yield self.transaction_actions.have_responded(transaction)
-
-        if response:
-            logger.debug("[%s] We've already responed to this request",
-                         transaction.transaction_id)
-            defer.returnValue(response)
-            return
-
-        logger.debug("[%s] Transaction is new", transaction.transaction_id)
-
-        with PreserveLoggingContext():
-            dl = []
-            for pdu in pdu_list:
-                dl.append(self._handle_new_pdu(transaction.origin, pdu))
-
-            if hasattr(transaction, "edus"):
-                for edu in [Edu(**x) for x in transaction.edus]:
-                    self.received_edu(
-                        transaction.origin,
-                        edu.edu_type,
-                        edu.content
-                    )
-
-            results = yield defer.DeferredList(dl)
-
-        ret = []
-        for r in results:
-            if r[0]:
-                ret.append({})
-            else:
-                logger.exception(r[1])
-                ret.append({"error": str(r[1])})
-
-        logger.debug("Returning: %s", str(ret))
-
-        yield self.transaction_actions.set_response(
-            transaction,
-            200, response
-        )
-        defer.returnValue((200, response))
-
-    def received_edu(self, origin, edu_type, content):
-        if edu_type in self.edu_handlers:
-            self.edu_handlers[edu_type](origin, content)
-        else:
-            logger.warn("Received EDU of type %s with no handler", edu_type)
-
-    @defer.inlineCallbacks
-    @log_function
-    def on_context_state_request(self, origin, context, event_id):
-        if event_id:
-            pdus = yield self.handler.get_state_for_pdu(
-                origin,
-                context,
-                event_id,
-            )
-            auth_chain = yield self.store.get_auth_chain(
-                [pdu.event_id for pdu in pdus]
-            )
-        else:
-            raise NotImplementedError("Specify an event")
-
-        defer.returnValue((200, {
-            "pdus": [pdu.get_pdu_json() for pdu in pdus],
-            "auth_chain": [pdu.get_pdu_json() for pdu in auth_chain],
-        }))
-
-    @defer.inlineCallbacks
-    @log_function
-    def on_pdu_request(self, origin, event_id):
-        pdu = yield self._get_persisted_pdu(origin, event_id)
-
-        if pdu:
-            defer.returnValue(
-                (200, self._transaction_from_pdus([pdu]).get_dict())
-            )
-        else:
-            defer.returnValue((404, ""))
-
-    @defer.inlineCallbacks
-    @log_function
-    def on_pull_request(self, origin, versions):
-        raise NotImplementedError("Pull transacions not implemented")
-
-    @defer.inlineCallbacks
-    def on_query_request(self, query_type, args):
-        if query_type in self.query_handlers:
-            response = yield self.query_handlers[query_type](args)
-            defer.returnValue((200, response))
-        else:
-            defer.returnValue(
-                (404, "No handler for Query type '%s'" % (query_type, ))
-            )
-
-    @defer.inlineCallbacks
-    def on_make_join_request(self, context, user_id):
-        pdu = yield self.handler.on_make_join_request(context, user_id)
-        time_now = self._clock.time_msec()
-        defer.returnValue({
-            "event": pdu.get_pdu_json(time_now),
-        })
-
-    @defer.inlineCallbacks
-    def on_invite_request(self, origin, content):
-        pdu = self.event_from_pdu_json(content)
-        ret_pdu = yield self.handler.on_invite_request(origin, pdu)
-        time_now = self._clock.time_msec()
-        defer.returnValue(
-            (
-                200,
-                {
-                    "event": ret_pdu.get_pdu_json(time_now),
-                }
-            )
-        )
-
-    @defer.inlineCallbacks
-    def on_send_join_request(self, origin, content):
-        logger.debug("on_send_join_request: content: %s", content)
-        pdu = self.event_from_pdu_json(content)
-        logger.debug("on_send_join_request: pdu sigs: %s", pdu.signatures)
-        res_pdus = yield self.handler.on_send_join_request(origin, pdu)
-        time_now = self._clock.time_msec()
-        defer.returnValue((200, {
-            "state": [p.get_pdu_json(time_now) for p in res_pdus["state"]],
-            "auth_chain": [
-                p.get_pdu_json(time_now) for p in res_pdus["auth_chain"]
-            ],
-        }))
-
-    @defer.inlineCallbacks
-    def on_event_auth(self, origin, context, event_id):
-        time_now = self._clock.time_msec()
-        auth_pdus = yield self.handler.on_event_auth(event_id)
-        defer.returnValue(
-            (
-                200,
-                {
-                    "auth_chain": [
-                        a.get_pdu_json(time_now) for a in auth_pdus
-                    ],
-                }
-            )
-        )
-
-    @defer.inlineCallbacks
-    def make_join(self, destination, context, user_id):
-        ret = yield self.transport_layer.make_join(
-            destination=destination,
-            context=context,
-            user_id=user_id,
-        )
-
-        pdu_dict = ret["event"]
-
-        logger.debug("Got response to make_join: %s", pdu_dict)
-
-        defer.returnValue(self.event_from_pdu_json(pdu_dict))
-
-    @defer.inlineCallbacks
-    def send_join(self, destination, pdu):
-        time_now = self._clock.time_msec()
-        _, content = yield self.transport_layer.send_join(
-            destination,
-            pdu.room_id,
-            pdu.event_id,
-            pdu.get_pdu_json(time_now),
-        )
-
-        logger.debug("Got content: %s", content)
-
-        state = [
-            self.event_from_pdu_json(p, outlier=True)
-            for p in content.get("state", [])
-        ]
-
-        # FIXME: We probably want to do something with the auth_chain given
-        # to us
-
-        auth_chain = [
-            self.event_from_pdu_json(p, outlier=True)
-            for p in content.get("auth_chain", [])
-        ]
-
-        auth_chain.sort(key=lambda e: e.depth)
-
-        defer.returnValue({
-            "state": state,
-            "auth_chain": auth_chain,
-        })
-
-    @defer.inlineCallbacks
-    def send_invite(self, destination, context, event_id, pdu):
-        time_now = self._clock.time_msec()
-        code, content = yield self.transport_layer.send_invite(
-            destination=destination,
-            context=context,
-            event_id=event_id,
-            content=pdu.get_pdu_json(time_now),
-        )
-
-        pdu_dict = content["event"]
-
-        logger.debug("Got response to send_invite: %s", pdu_dict)
-
-        defer.returnValue(self.event_from_pdu_json(pdu_dict))
-
-    @log_function
-    def _get_persisted_pdu(self, origin, event_id, do_auth=True):
-        """ Get a PDU from the database with given origin and id.
-
-        Returns:
-            Deferred: Results in a `Pdu`.
-        """
-        return self.handler.get_persisted_pdu(
-            origin, event_id, do_auth=do_auth
-        )
-
-    def _transaction_from_pdus(self, pdu_list):
-        """Returns a new Transaction containing the given PDUs suitable for
-        transmission.
-        """
-        time_now = self._clock.time_msec()
-        pdus = [p.get_pdu_json(time_now) for p in pdu_list]
-        return Transaction(
-            origin=self.server_name,
-            pdus=pdus,
-            origin_server_ts=int(time_now),
-            destination=None,
-        )
-
-    @defer.inlineCallbacks
-    @log_function
-    def _handle_new_pdu(self, origin, pdu, backfilled=False):
-        # We reprocess pdus when we have seen them only as outliers
-        existing = yield self._get_persisted_pdu(
-            origin, pdu.event_id, do_auth=False
-        )
-
-        already_seen = (
-            existing and (
-                not existing.internal_metadata.is_outlier()
-                or pdu.internal_metadata.is_outlier()
-            )
-        )
-        if already_seen:
-            logger.debug("Already seen pdu %s", pdu.event_id)
-            defer.returnValue({})
-            return
-
-        state = None
-
-        auth_chain = []
-
-        # We need to make sure we have all the auth events.
-        # for e_id, _ in pdu.auth_events:
-        #     exists = yield self._get_persisted_pdu(
-        #         origin,
-        #         e_id,
-        #         do_auth=False
-        #     )
-        #
-        #     if not exists:
-        #         try:
-        #             logger.debug(
-        #                 "_handle_new_pdu fetch missing auth event %s from %s",
-        #                 e_id,
-        #                 origin,
-        #             )
-        #
-        #             yield self.get_pdu(
-        #                 origin,
-        #                 event_id=e_id,
-        #                 outlier=True,
-        #             )
-        #
-        #             logger.debug("Processed pdu %s", e_id)
-        #         except:
-        #             logger.warn(
-        #                 "Failed to get auth event %s from %s",
-        #                 e_id,
-        #                 origin
-        #             )
-
-        # Get missing pdus if necessary.
-        if not pdu.internal_metadata.is_outlier():
-            # We only backfill backwards to the min depth.
-            min_depth = yield self.handler.get_min_depth_for_context(
-                pdu.room_id
-            )
-
-            logger.debug(
-                "_handle_new_pdu min_depth for %s: %d",
-                pdu.room_id, min_depth
-            )
-
-            if min_depth and pdu.depth > min_depth:
-                for event_id, hashes in pdu.prev_events:
-                    exists = yield self._get_persisted_pdu(
-                        origin,
-                        event_id,
-                        do_auth=False
-                    )
-
-                    if not exists:
-                        logger.debug(
-                            "_handle_new_pdu requesting pdu %s",
-                            event_id
-                        )
-
-                        try:
-                            yield self.get_pdu(
-                                origin,
-                                event_id=event_id,
-                            )
-                            logger.debug("Processed pdu %s", event_id)
-                        except:
-                            # TODO(erikj): Do some more intelligent retries.
-                            logger.exception("Failed to get PDU")
-            else:
-                # We need to get the state at this event, since we have reached
-                # a backward extremity edge.
-                logger.debug(
-                    "_handle_new_pdu getting state for %s",
-                    pdu.room_id
-                )
-                state, auth_chain = yield self.get_state_for_context(
-                    origin, pdu.room_id, pdu.event_id,
-                )
-
-        if not backfilled:
-            ret = yield self.handler.on_receive_pdu(
-                origin,
-                pdu,
-                backfilled=backfilled,
-                state=state,
-                auth_chain=auth_chain,
-            )
-        else:
-            ret = None
-
-        # yield self.pdu_actions.mark_as_processed(pdu)
+        self.transaction_actions = TransactionActions(self.store)
+        self._transaction_queue = TransactionQueue(hs, transport_layer)
 
-        defer.returnValue(ret)
+        self._order = 0
 
     def __str__(self):
         return "<ReplicationLayer(%s)>" % self.server_name
-
-    def event_from_pdu_json(self, pdu_json, outlier=False):
-        event = FrozenEvent(
-            pdu_json
-        )
-
-        event.internal_metadata.outlier = outlier
-
-        return event
-
-
-class _TransactionQueue(object):
-    """This class makes sure we only have one transaction in flight at
-    a time for a given destination.
-
-    It batches pending PDUs into single transactions.
-    """
-
-    def __init__(self, hs, transaction_actions, transport_layer):
-        self.server_name = hs.hostname
-        self.transaction_actions = transaction_actions
-        self.transport_layer = transport_layer
-
-        self._clock = hs.get_clock()
-        self.store = hs.get_datastore()
-
-        # Is a mapping from destinations -> deferreds. Used to keep track
-        # of which destinations have transactions in flight and when they are
-        # done
-        self.pending_transactions = {}
-
-        # Is a mapping from destination -> list of
-        # tuple(pending pdus, deferred, order)
-        self.pending_pdus_by_dest = {}
-        # destination -> list of tuple(edu, deferred)
-        self.pending_edus_by_dest = {}
-
-        # destination -> list of tuple(failure, deferred)
-        self.pending_failures_by_dest = {}
-
-        # HACK to get unique tx id
-        self._next_txn_id = int(self._clock.time_msec())
-
-    @defer.inlineCallbacks
-    @log_function
-    def enqueue_pdu(self, pdu, destinations, order):
-        # We loop through all destinations to see whether we already have
-        # a transaction in progress. If we do, stick it in the pending_pdus
-        # table and we'll get back to it later.
-
-        destinations = set(destinations)
-        destinations.discard(self.server_name)
-        destinations.discard("localhost")
-
-        logger.debug("Sending to: %s", str(destinations))
-
-        if not destinations:
-            return
-
-        deferreds = []
-
-        for destination in destinations:
-            deferred = defer.Deferred()
-            self.pending_pdus_by_dest.setdefault(destination, []).append(
-                (pdu, deferred, order)
-            )
-
-            def eb(failure):
-                if not deferred.called:
-                    deferred.errback(failure)
-                else:
-                    logger.warn("Failed to send pdu", failure)
-
-            with PreserveLoggingContext():
-                self._attempt_new_transaction(destination).addErrback(eb)
-
-            deferreds.append(deferred)
-
-        yield defer.DeferredList(deferreds)
-
-    # NO inlineCallbacks
-    def enqueue_edu(self, edu):
-        destination = edu.destination
-
-        if destination == self.server_name:
-            return
-
-        deferred = defer.Deferred()
-        self.pending_edus_by_dest.setdefault(destination, []).append(
-            (edu, deferred)
-        )
-
-        def eb(failure):
-            if not deferred.called:
-                deferred.errback(failure)
-            else:
-                logger.warn("Failed to send edu", failure)
-
-        with PreserveLoggingContext():
-            self._attempt_new_transaction(destination).addErrback(eb)
-
-        return deferred
-
-    @defer.inlineCallbacks
-    def enqueue_failure(self, failure, destination):
-        deferred = defer.Deferred()
-
-        self.pending_failures_by_dest.setdefault(
-            destination, []
-        ).append(
-            (failure, deferred)
-        )
-
-        yield deferred
-
-    @defer.inlineCallbacks
-    @log_function
-    def _attempt_new_transaction(self, destination):
-
-        (retry_last_ts, retry_interval) = (0, 0)
-        retry_timings = yield self.store.get_destination_retry_timings(
-            destination
-        )
-        if retry_timings:
-            (retry_last_ts, retry_interval) = (
-                retry_timings.retry_last_ts, retry_timings.retry_interval
-            )
-            if retry_last_ts + retry_interval > int(self._clock.time_msec()):
-                logger.info(
-                    "TX [%s] not ready for retry yet - "
-                    "dropping transaction for now",
-                    destination,
-                )
-                return
-            else:
-                logger.info("TX [%s] is ready for retry", destination)
-
-        logger.info("TX [%s] _attempt_new_transaction", destination)
-        
-        if destination in self.pending_transactions:
-            # XXX: pending_transactions can get stuck on by a never-ending
-            # request at which point pending_pdus_by_dest just keeps growing.
-            # we need application-layer timeouts of some flavour of these
-            # requests
-            return
-
-        # list of (pending_pdu, deferred, order)
-        pending_pdus = self.pending_pdus_by_dest.pop(destination, [])
-        pending_edus = self.pending_edus_by_dest.pop(destination, [])
-        pending_failures = self.pending_failures_by_dest.pop(destination, [])
-
-        if pending_pdus:
-            logger.info("TX [%s] len(pending_pdus_by_dest[dest]) = %d", destination, len(pending_pdus))
-
-        if not pending_pdus and not pending_edus and not pending_failures:
-            return
-
-        logger.debug(
-            "TX [%s] Attempting new transaction "
-            "(pdus: %d, edus: %d, failures: %d)",
-            destination,
-            len(pending_pdus),
-            len(pending_edus),
-            len(pending_failures)
-        )
-
-        # Sort based on the order field
-        pending_pdus.sort(key=lambda t: t[2])
-
-        pdus = [x[0] for x in pending_pdus]
-        edus = [x[0] for x in pending_edus]
-        failures = [x[0].get_dict() for x in pending_failures]
-        deferreds = [
-            x[1]
-            for x in pending_pdus + pending_edus + pending_failures
-        ]
-
-        try:
-            self.pending_transactions[destination] = 1
-
-            logger.debug("TX [%s] Persisting transaction...", destination)
-
-            transaction = Transaction.create_new(
-                origin_server_ts=int(self._clock.time_msec()),
-                transaction_id=str(self._next_txn_id),
-                origin=self.server_name,
-                destination=destination,
-                pdus=pdus,
-                edus=edus,
-                pdu_failures=failures,
-            )
-
-            self._next_txn_id += 1
-
-            yield self.transaction_actions.prepare_to_send(transaction)
-
-            logger.debug("TX [%s] Persisted transaction", destination)
-            logger.info(
-                "TX [%s] Sending transaction [%s]",
-                destination,
-                transaction.transaction_id,
-            )
-
-            # Actually send the transaction
-
-            # FIXME (erikj): This is a bit of a hack to make the Pdu age
-            # keys work
-            def json_data_cb():
-                data = transaction.get_dict()
-                now = int(self._clock.time_msec())
-                if "pdus" in data:
-                    for p in data["pdus"]:
-                        if "age_ts" in p:
-                            unsigned = p.setdefault("unsigned", {})
-                            unsigned["age"] = now - int(p["age_ts"])
-                            del p["age_ts"]
-                return data
-
-            code, response = yield self.transport_layer.send_transaction(
-                transaction, json_data_cb
-            )
-
-            logger.info("TX [%s] got %d response", destination, code)
-
-            logger.debug("TX [%s] Sent transaction", destination)
-            logger.debug("TX [%s] Marking as delivered...", destination)
-
-            yield self.transaction_actions.delivered(
-                transaction, code, response
-            )
-
-            logger.debug("TX [%s] Marked as delivered", destination)
-            logger.debug("TX [%s] Yielding to callbacks...", destination)
-
-            for deferred in deferreds:
-                if code == 200:
-                    if retry_last_ts:
-                        # this host is alive! reset retry schedule
-                        yield self.store.set_destination_retry_timings(
-                            destination, 0, 0
-                        )
-                    deferred.callback(None)
-                else:
-                    self.set_retrying(destination, retry_interval)
-                    deferred.errback(RuntimeError("Got status %d" % code))
-
-                # Ensures we don't continue until all callbacks on that
-                # deferred have fired
-                try:
-                    yield deferred
-                except:
-                    pass
-
-            logger.debug("TX [%s] Yielded to callbacks", destination)
-
-        except Exception as e:
-            # We capture this here as there as nothing actually listens
-            # for this finishing functions deferred.
-            logger.warn(
-                "TX [%s] Problem in _attempt_transaction: %s",
-                destination,
-                e,
-            )
-
-            self.set_retrying(destination, retry_interval)
-
-            for deferred in deferreds:
-                if not deferred.called:
-                    deferred.errback(e)
-
-        finally:
-            # We want to be *very* sure we delete this after we stop processing
-            self.pending_transactions.pop(destination, None)
-
-            # Check to see if there is anything else to send.
-            self._attempt_new_transaction(destination)
-
-    @defer.inlineCallbacks
-    def set_retrying(self, destination, retry_interval):
-        # track that this destination is having problems and we should
-        # give it a chance to recover before trying it again
-
-        if retry_interval:
-            retry_interval *= 2
-            # plateau at hourly retries for now
-            if retry_interval >= 60 * 60 * 1000:
-                retry_interval = 60 * 60 * 1000
-        else:
-            retry_interval = 2000  # try again at first after 2 seconds
-
-        yield self.store.set_destination_retry_timings(
-            destination,
-            int(self._clock.time_msec()),
-            retry_interval
-        )