From b811c9857491c0569ae367708721fbbaebf3adab Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 6 Aug 2015 14:01:27 +0100
Subject: [PATCH] Remove failed deferreds from cache

---
 synapse/storage/_base.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 8384299a1..99c094875 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -205,8 +205,14 @@ class CacheDescriptor(object):
                     self.function_to_call,
                     obj, *args, **kwargs
                 )
-                ret = ObservableDeferred(ret, consumeErrors=False)
 
+                def onErr(f):
+                    cache.invalidate(*keyargs)
+                    return f
+
+                ret.addErrback(onErr)
+
+                ret = ObservableDeferred(ret, consumeErrors=False)
                 cache.update(sequence, *(keyargs + [ret]))
 
                 return ret.observe()