From aed62a35832a3ec1c7425ecc99cab06a781263ba Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Sun, 7 Dec 2014 02:26:07 +0000
Subject: track replication destination health, and perform exponential
 back-off when sending transactions. does *not* yet retry transactions, but
 drops them on the floor if waiting for a server to recover.

---
 synapse/http/matrixfederationclient.py | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'synapse/http')

diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 510f07dd7b..3edc59dbab 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -89,7 +89,7 @@ class MatrixFederationHttpClient(object):
             ("", "", path_bytes, param_bytes, query_bytes, "",)
         )
 
-        logger.debug("Sending request to %s: %s %s",
+        logger.info("Sending request to %s: %s %s",
                      destination, method, url_bytes)
 
         logger.debug(
@@ -101,7 +101,10 @@ class MatrixFederationHttpClient(object):
             ]
         )
 
-        retries_left = 5
+        # was 5; for now, let's only try once at the HTTP layer and then
+        # rely on transaction-layer retries for exponential backoff and
+        # getting the message through.
+        retries_left = 0
 
         endpoint = self._getEndpoint(reactor, destination)
 
@@ -131,7 +134,8 @@ class MatrixFederationHttpClient(object):
                                 e)
                     raise SynapseError(400, "Domain specified not found.")
 
-                logger.exception("Got error in _create_request")
+                logger.exception("Sending request failed to %s: %s %s : %s",
+                    destination, method, url_bytes, e)
                 _print_ex(e)
 
                 if retries_left:
@@ -140,15 +144,15 @@ class MatrixFederationHttpClient(object):
                 else:
                     raise
 
+        logger.info("Received response %d %s for %s: %s %s",
+            response.code, response.phrase, destination, method, url_bytes)
+        
         if 200 <= response.code < 300:
             # We need to update the transactions table to say it was sent?
             pass
         else:
             # :'(
             # Update transactions table?
-            logger.error(
-                "Got response %d %s", response.code, response.phrase
-            )
             raise CodeMessageException(
                 response.code, response.phrase
             )
-- 
cgit 1.4.1


From 2b1acb7671e33baeb01be2f0facd20cd6ea7e3b5 Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Wed, 10 Dec 2014 00:03:55 +0000
Subject: squidge to 79 columns as per pep8

---
 synapse/federation/replication.py      | 30 ++++++++++++++++++++----------
 synapse/http/matrixfederationclient.py |  7 ++++---
 synapse/storage/transactions.py        | 18 ++++++++++++------
 3 files changed, 36 insertions(+), 19 deletions(-)

(limited to 'synapse/http')

diff --git a/synapse/federation/replication.py b/synapse/federation/replication.py
index c4c6667b62..c242488483 100644
--- a/synapse/federation/replication.py
+++ b/synapse/federation/replication.py
@@ -778,21 +778,25 @@ class _TransactionQueue(object):
     def _attempt_new_transaction(self, destination):
 
         (retry_last_ts, retry_interval) = (0, 0)
-        retry_timings = yield self.store.get_destination_retry_timings(destination)
+        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)
+                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)
         
         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
+            # 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)
@@ -803,8 +807,10 @@ class _TransactionQueue(object):
         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))
+        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])
@@ -837,7 +843,8 @@ class _TransactionQueue(object):
             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)
+            logger.info("TX [%s] Sending transaction [%s]", destination,
+                        transaction.transaction_id)
 
             # Actually send the transaction
 
@@ -874,7 +881,9 @@ class _TransactionQueue(object):
                 if code == 200:
                     if retry_last_ts:
                         # this host is alive! reset retry schedule
-                        yield self.store.set_destination_retry_timings(destination, 0, 0)
+                        yield self.store.set_destination_retry_timings(
+                            destination, 0, 0
+                        )
                     deferred.callback(None)
                 else:
                     self.start_retrying(destination, retry_interval)
@@ -892,7 +901,8 @@ class _TransactionQueue(object):
         except Exception as e:
             # We capture this here as there as nothing actually listens
             # for this finishing functions deferred.
-            logger.exception("TX [%s] Problem in _attempt_transaction: %s", destination, e)
+            logger.exception("TX [%s] Problem in _attempt_transaction: %s",
+                             destination, e)
 
             self.start_retrying(destination, retry_interval)
             
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 3edc59dbab..c76990904d 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -90,7 +90,7 @@ class MatrixFederationHttpClient(object):
         )
 
         logger.info("Sending request to %s: %s %s",
-                     destination, method, url_bytes)
+                    destination, method, url_bytes)
 
         logger.debug(
             "Types: %s",
@@ -135,7 +135,7 @@ class MatrixFederationHttpClient(object):
                     raise SynapseError(400, "Domain specified not found.")
 
                 logger.exception("Sending request failed to %s: %s %s : %s",
-                    destination, method, url_bytes, e)
+                                 destination, method, url_bytes, e)
                 _print_ex(e)
 
                 if retries_left:
@@ -145,7 +145,8 @@ class MatrixFederationHttpClient(object):
                     raise
 
         logger.info("Received response %d %s for %s: %s %s",
-            response.code, response.phrase, destination, method, url_bytes)
+                    response.code, response.phrase,
+                    destination, method, url_bytes)
         
         if 200 <= response.code < 300:
             # We need to update the transactions table to say it was sent?
diff --git a/synapse/storage/transactions.py b/synapse/storage/transactions.py
index 237b024451..2b16787695 100644
--- a/synapse/storage/transactions.py
+++ b/synapse/storage/transactions.py
@@ -28,7 +28,8 @@ class TransactionStore(SQLBaseStore):
     """A collection of queries for handling PDUs.
     """
     
-    # a write-through cache of DestinationsTable.EntryType indexed by destination string
+    # a write-through cache of DestinationsTable.EntryType indexed by
+    # destination string
     destination_retry_cache = {}
 
     def get_received_txn_response(self, transaction_id, origin):
@@ -238,7 +239,8 @@ class TransactionStore(SQLBaseStore):
             else:
                 return None
         
-    def set_destination_retry_timings(self, destination, retry_last_ts, retry_interval):
+    def set_destination_retry_timings(self, destination,
+                                      retry_last_ts, retry_interval):
         """Sets the current retry timings for a given destination.
         Both timings should be zero if retrying is no longer occuring.
         
@@ -249,15 +251,19 @@ class TransactionStore(SQLBaseStore):
         """
         
         self.destination_retry_cache[destination] = (
-            DestinationsTable.EntryType(destination, retry_last_ts, retry_interval)
+            DestinationsTable.EntryType(destination,
+                                        retry_last_ts, retry_interval)
         )
         
-        # xxx: we could chose to not bother persisting this if our cache things this is a NOOP
+        # XXX: we could chose to not bother persisting this if our cache thinks
+        # this is a NOOP
         return self.runInteraction(
             "set_destination_retry_timings",
-            self._set_destination_retry_timings, destination, retry_last_ts, retry_interval)
+            self._set_destination_retry_timings, destination, 
+            retry_last_ts, retry_interval)
             
-    def _set_destination_retry_timings(cls, txn, destination, retry_last_ts, retry_interval):
+    def _set_destination_retry_timings(cls, txn, destination,
+                                       retry_last_ts, retry_interval):
 
         query = (
             "INSERT OR REPLACE INTO %s "
-- 
cgit 1.4.1


From faf12b64f81627d92cb1ac49b6eb58f9d3f4837d Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Wed, 10 Dec 2014 00:12:51 +0000
Subject: add errbacks to enqueue_pdu deferreds; change logging for failed
 federation sends to warn rather than exception

---
 synapse/federation/replication.py      | 16 ++++++++++------
 synapse/http/matrixfederationclient.py |  4 ++--
 2 files changed, 12 insertions(+), 8 deletions(-)

(limited to 'synapse/http')

diff --git a/synapse/federation/replication.py b/synapse/federation/replication.py
index c242488483..346b5f04c0 100644
--- a/synapse/federation/replication.py
+++ b/synapse/federation/replication.py
@@ -334,7 +334,7 @@ class ReplicationLayer(object):
             defer.returnValue(response)
             return
 
-        logger.debug("[%s] Transacition is new", transaction.transaction_id)
+        logger.debug("[%s] Transaction is new", transaction.transaction_id)
 
         with PreserveLoggingContext():
             dl = []
@@ -724,15 +724,19 @@ class _TransactionQueue(object):
         deferreds = []
 
         for destination in destinations:
-            # XXX: why don't we specify an errback for this deferred
-            # like we do for EDUs? --matthew
             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)
+                self._attempt_new_transaction(destination).addErrback(eb)
 
             deferreds.append(deferred)
 
@@ -754,7 +758,7 @@ class _TransactionQueue(object):
             if not deferred.called:
                 deferred.errback(failure)
             else:
-                logger.exception("Failed to send edu", failure)
+                logger.warn("Failed to send edu", failure)
 
         with PreserveLoggingContext():
             self._attempt_new_transaction(destination).addErrback(eb)
@@ -901,7 +905,7 @@ class _TransactionQueue(object):
         except Exception as e:
             # We capture this here as there as nothing actually listens
             # for this finishing functions deferred.
-            logger.exception("TX [%s] Problem in _attempt_transaction: %s",
+            logger.warn("TX [%s] Problem in _attempt_transaction: %s",
                              destination, e)
 
             self.start_retrying(destination, retry_interval)
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index c76990904d..8fc6bf8f97 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -134,7 +134,7 @@ class MatrixFederationHttpClient(object):
                                 e)
                     raise SynapseError(400, "Domain specified not found.")
 
-                logger.exception("Sending request failed to %s: %s %s : %s",
+                logger.warn("Sending request failed to %s: %s %s : %s",
                                  destination, method, url_bytes, e)
                 _print_ex(e)
 
@@ -289,7 +289,7 @@ def _print_ex(e):
         for ex in e.reasons:
             _print_ex(ex)
     else:
-        logger.exception(e)
+        logger.warn(e)
 
 
 class _JsonProducer(object):
-- 
cgit 1.4.1


From b8d30899b1296347a75d5a59e32d73a5236e6ea2 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 10 Dec 2014 10:16:09 +0000
Subject: Code style.

---
 synapse/federation/replication.py      | 52 +++++++++++++++++++++++-----------
 synapse/http/matrixfederationclient.py | 29 +++++++++++++------
 synapse/storage/transactions.py        | 50 ++++++++++++++++++--------------
 3 files changed, 85 insertions(+), 46 deletions(-)

(limited to 'synapse/http')

diff --git a/synapse/federation/replication.py b/synapse/federation/replication.py
index 589a3f581b..0cb632fb08 100644
--- a/synapse/federation/replication.py
+++ b/synapse/federation/replication.py
@@ -728,7 +728,7 @@ class _TransactionQueue(object):
             self.pending_pdus_by_dest.setdefault(destination, []).append(
                 (pdu, deferred, order)
             )
-            
+
             def eb(failure):
                 if not deferred.called:
                     deferred.errback(failure)
@@ -745,7 +745,7 @@ class _TransactionQueue(object):
     # NO inlineCallbacks
     def enqueue_edu(self, edu):
         destination = edu.destination
-        
+
         if destination == self.server_name:
             return
 
@@ -776,7 +776,7 @@ class _TransactionQueue(object):
         )
 
         yield deferred
-        
+
     @defer.inlineCallbacks
     @log_function
     def _attempt_new_transaction(self, destination):
@@ -790,12 +790,15 @@ class _TransactionQueue(object):
                 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)
+                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)
-        
+
         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.
@@ -811,10 +814,14 @@ class _TransactionQueue(object):
         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)",
+        logger.debug(
+            "TX [%s] Attempting new transaction "
+            "(pdus: %d, edus: %d, failures: %d)",
             destination,
-            len(pending_pdus), len(pending_edus), len(pending_failures))
+            len(pending_pdus),
+            len(pending_edus),
+            len(pending_failures)
+        )
 
         # Sort based on the order field
         pending_pdus.sort(key=lambda t: t[2])
@@ -847,8 +854,11 @@ class _TransactionQueue(object):
             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)
+            logger.info(
+                "TX [%s] Sending transaction [%s]",
+                destination,
+                transaction.transaction_id,
+            )
 
             # Actually send the transaction
 
@@ -905,11 +915,14 @@ class _TransactionQueue(object):
         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)
+            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)
@@ -925,12 +938,17 @@ class _TransactionQueue(object):
     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)
+            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
+        )
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 8fc6bf8f97..16fb2adab5 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -130,12 +130,20 @@ class MatrixFederationHttpClient(object):
                 break
             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)
+                    logger.warn(
+                        "DNS Lookup failed to %s with %s",
+                        destination,
+                        e
+                    )
                     raise SynapseError(400, "Domain specified not found.")
 
-                logger.warn("Sending request failed to %s: %s %s : %s",
-                                 destination, method, url_bytes, e)
+                logger.warn(
+                    "Sending request failed to %s: %s %s : %s",
+                    destination,
+                    method,
+                    url_bytes,
+                    e
+                )
                 _print_ex(e)
 
                 if retries_left:
@@ -144,10 +152,15 @@ class MatrixFederationHttpClient(object):
                 else:
                     raise
 
-        logger.info("Received response %d %s for %s: %s %s",
-                    response.code, response.phrase,
-                    destination, method, url_bytes)
-        
+        logger.info(
+            "Received response %d %s for %s: %s %s",
+            response.code,
+            response.phrase,
+            destination,
+            method,
+            url_bytes
+        )
+
         if 200 <= response.code < 300:
             # We need to update the transactions table to say it was sent?
             pass
diff --git a/synapse/storage/transactions.py b/synapse/storage/transactions.py
index 2b16787695..423cc3f02a 100644
--- a/synapse/storage/transactions.py
+++ b/synapse/storage/transactions.py
@@ -27,7 +27,7 @@ logger = logging.getLogger(__name__)
 class TransactionStore(SQLBaseStore):
     """A collection of queries for handling PDUs.
     """
-    
+
     # a write-through cache of DestinationsTable.EntryType indexed by
     # destination string
     destination_retry_cache = {}
@@ -213,21 +213,21 @@ class TransactionStore(SQLBaseStore):
 
     def get_destination_retry_timings(self, destination):
         """Gets the current retry timings (if any) for a given destination.
-        
+
         Args:
             destination (str)
-        
+
         Returns:
             None if not retrying
             Otherwise a DestinationsTable.EntryType for the retry scheme
         """
         if destination in self.destination_retry_cache:
             return defer.succeed(self.destination_retry_cache[destination])
-        
+
         return self.runInteraction(
             "get_destination_retry_timings",
             self._get_destination_retry_timings, destination)
-            
+
     def _get_destination_retry_timings(cls, txn, destination):
         query = DestinationsTable.select_statement("destination = ?")
         txn.execute(query, (destination,))
@@ -238,30 +238,36 @@ class TransactionStore(SQLBaseStore):
                 return result
             else:
                 return None
-        
+
     def set_destination_retry_timings(self, destination,
                                       retry_last_ts, retry_interval):
         """Sets the current retry timings for a given destination.
         Both timings should be zero if retrying is no longer occuring.
-        
+
         Args:
             destination (str)
             retry_last_ts (int) - time of last retry attempt in unix epoch ms
             retry_interval (int) - how long until next retry in ms
         """
-        
+
         self.destination_retry_cache[destination] = (
-            DestinationsTable.EntryType(destination,
-                                        retry_last_ts, retry_interval)
+            DestinationsTable.EntryType(
+                destination,
+                retry_last_ts,
+                retry_interval
+            )
         )
-        
+
         # XXX: we could chose to not bother persisting this if our cache thinks
         # this is a NOOP
         return self.runInteraction(
             "set_destination_retry_timings",
-            self._set_destination_retry_timings, destination, 
-            retry_last_ts, retry_interval)
-            
+            self._set_destination_retry_timings,
+            destination,
+            retry_last_ts,
+            retry_interval,
+        )
+
     def _set_destination_retry_timings(cls, txn, destination,
                                        retry_last_ts, retry_interval):
 
@@ -275,21 +281,22 @@ class TransactionStore(SQLBaseStore):
 
     def get_destinations_needing_retry(self):
         """Get all destinations which are due a retry for sending a transaction.
-                    
+
         Returns:
             list: A list of `DestinationsTable.EntryType`
         """
-                
+
         return self.runInteraction(
             "get_destinations_needing_retry",
             self._get_destinations_needing_retry
         )
-        
+
     def _get_destinations_needing_retry(cls, txn):
         where = "retry_last_ts > 0 and retry_next_ts < now()"
         query = DestinationsTable.select_statement(where)
         txn.execute(query)
-        return DestinationsTable.decode_results(txn.fetchall())    
+        return DestinationsTable.decode_results(txn.fetchall())
+
 
 class ReceivedTransactionsTable(Table):
     table_name = "received_transactions"
@@ -332,14 +339,15 @@ class TransactionsToPduTable(Table):
     ]
 
     EntryType = namedtuple("TransactionsToPduEntry", fields)
-    
+
+
 class DestinationsTable(Table):
     table_name = "destinations"
-    
+
     fields = [
         "destination",
         "retry_last_ts",
         "retry_interval",
     ]
 
-    EntryType = namedtuple("DestinationsEntry", fields)
\ No newline at end of file
+    EntryType = namedtuple("DestinationsEntry", fields)
-- 
cgit 1.4.1


From 0f4dcab238b029407080cb02cc2cf14e22d8fe89 Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Wed, 10 Dec 2014 10:28:27 +0000
Subject: turn back on per-request transaction retries, so that every time we
 try to hit a dead server we actually end up hammering 5 times :|

---
 synapse/http/matrixfederationclient.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

(limited to 'synapse/http')

diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 16fb2adab5..fc5b5ab809 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -101,10 +101,9 @@ class MatrixFederationHttpClient(object):
             ]
         )
 
-        # was 5; for now, let's only try once at the HTTP layer and then
-        # rely on transaction-layer retries for exponential backoff and
-        # getting the message through.
-        retries_left = 0
+        # XXX: Would be much nicer to retry only at the transaction-layer
+        # (once we have reliable transactions in place)
+        retries_left = 5
 
         endpoint = self._getEndpoint(reactor, destination)
 
-- 
cgit 1.4.1