From 10aaa1bc15775a228ce22ab45efbb55b5099289b Mon Sep 17 00:00:00 2001 From: Richard van der Hoff Date: Thu, 16 Nov 2017 15:30:15 +0000 Subject: [PATCH] _simple_upsert: retry on IntegrityError wrap the call to _simple_upsert_txn in a loop so that we retry on an integrityerror: this means we can avoid locking the table provided there is an unique index. --- synapse/storage/_base.py | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py index 740400d58b..1582a58966 100644 --- a/synapse/storage/_base.py +++ b/synapse/storage/_base.py @@ -469,23 +469,46 @@ class SQLBaseStore(object): txn.executemany(sql, vals) + @defer.inlineCallbacks def _simple_upsert(self, table, keyvalues, values, insertion_values={}, desc="_simple_upsert", lock=True): """ + + `lock` should generally be set to True (the default), but can be set + to False if either of the following are true: + + * there is a UNIQUE INDEX on the key columns. In this case a conflict + will cause an IntegrityError in which case this function will retry + the update. + + * we somehow know that we are the only thread which will be updating + this table. + Args: table (str): The table to upsert into keyvalues (dict): The unique key tables and their new values values (dict): The nonunique columns and their new values - insertion_values (dict): key/values to use when inserting + insertion_values (dict): additional key/values to use only when + inserting + lock (bool): True to lock the table when doing the upsert. Returns: Deferred(bool): True if a new entry was created, False if an existing one was updated. """ - return self.runInteraction( - desc, - self._simple_upsert_txn, table, keyvalues, values, insertion_values, - lock - ) + while True: + try: + result = yield self.runInteraction( + desc, + self._simple_upsert_txn, table, keyvalues, values, insertion_values, + lock=lock + ) + defer.returnValue(result) + except self.database_engine.IntegrityError as e: + # presumably we raced with another transaction: let's retry. + logger.warn( + "IntegrityError when upserting into %s; retrying: %s", + table, e + ) def _simple_upsert_txn(self, txn, table, keyvalues, values, insertion_values={}, lock=True):