I only recently noticed it happening more frequently after I implemented session management on top of datastore and memcache, but, now, as I actually explicitly push data into memcache, it is now happening constantly. Most often, I'll get this error every time until I flush, it will work once, and then I'll get this error every time afterward.
The requests that are inciting the issue are very simple (try get from memcache, do get from datastore, put to memcache), so they're very quick. The request either completes or fails within a second. Any ideas?
<-- Current user reconcile here.
2016/09/01 03:00:42 DEBUG: Session save not necessary: [DCRBDGRY6RMWANCSJXVLD7GULDH4NZEB6SBAQ3KSFIGA2LP45IIQ]
2016/09/01 03:00:42 DEBUG: Got session: [DCRBDGRY6RMWANCSJXVLD7GULDH4NZEB6SBAQ3KSFIGA2LP45IIQ]
2016/09/01 03:00:42 DEBUG: Found user in session.
<-- Request-specific handler logic here.
2016/09/01 03:00:42 DEBUG: Cache hit: [type.family:522450f6795592f844a27213a2dddf8de169f204]
2016/09/01 03:00:42 ERROR: context expired before API call datastore_v3/Put completed
request URL: /api/1/type/family/522450f6795592f844a27213a2dddf8de169f204
panic: Call error 3: invalid security ticket (context expired)
Maybe if I could understand the nature of the failure and how it might potentially be tricked to fire so early I might be more helpful in providing more information?