http txns: Do not cache error responses

Previously we did. This meant that, amongst other errors, rate-limiting errors
would be cached and prevent messages with that txn ID being sent.
This commit is contained in:
Kegan Dougal 2017-02-13 13:16:48 +00:00
parent 6bba80241c
commit ecd7e36047

View file

@ -81,7 +81,16 @@ class HttpTransactionCache(object):
Deferred which resolves to a tuple of (response_code, response_dict).
"""
try:
return self.transactions[txn_key][0].observe()
observable = self.transactions[txn_key][0]
if not observable.has_called() or observable.has_succeeded():
return observable.observe()
# if the request has already been called with a non-2xx status
# (a Twisted failure), remove it from the transaction map.
# This is done to ensure that we don't cache rate-limiting errors, etc.
res = observable.get_result()
if res.value.code >= 300:
del self.transactions[txn_key]
# fall through
except (KeyError, IndexError):
pass # execute the function instead.