GAE error (Error code 104) while creating a new blob - google-app-engine

Question

On GAE this line of code:
file_name = files.blobstore.create(mime_type='image/png')
drops google.appengine.runtime.DeadlineExceededError
Here is the full method code:
class UploadsHandler(JSONRequestHandler):
def upload_blob(self, content, filename):
file_name = files.blobstore.create(mime_type='image/png')
file_str_list = split_len(content, 65520)
with files.open(file_name, 'a') as f:
for line in file_str_list:
f.write(line)
files.finalize(file_name)
return files.blobstore.get_blob_key(file_name)
Logging message ends with:
A serious problem was encountered with the process that handled this request, causing it to exit. This is likely to cause a new process to be used for the next request to your application. If you see this message frequently, you may be throwing exceptions during the initialization of your application. (Error code 104)
Full error stack:
<class 'google.appengine.runtime.DeadlineExceededError'>:
Traceback (most recent call last):
File "/base/data/home/apps/s~mockup-cloud/1.352909931378411668/main.py", line 389, in main
util.run_wsgi_app(application)
File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/util.py", line 98, in run_wsgi_app
run_bare_wsgi_app(add_wsgi_middleware(application))
File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/util.py", line 116, in run_bare_wsgi_app
result = application(env, _start_response)
File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/_webapp25.py", line 703, in __call__
handler.post(*groups)
File "/base/data/home/apps/s~mockup-cloud/1.352909931378411668/main.py", line 339, in post
original_key = "%s" % self.upload_blob(src)
File "/base/data/home/apps/s~mockup-cloud/1.352909931378411668/main.py", line 268, in upload_blob
file_name = files.blobstore.create(mime_type='image/png')
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/files/blobstore.py", line 68, in create
return files._create(_BLOBSTORE_FILESYSTEM, params=params)
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/files/file.py", line 487, in _create
_make_call('Create', request, response)
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/files/file.py", line 228, in _make_call
rpc.wait()
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/apiproxy_stub_map.py", line 533, in wait
self.__rpc.Wait()
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/apiproxy_rpc.py", line 119, in Wait
rpc_completed = self._WaitImpl()
File "/base/python_runtime/python_lib/versions/1/google/appengine/runtime/apiproxy.py", line 131, in _WaitImpl
rpc_completed = _apphosting_runtime___python__apiproxy.Wait(self)
Blob is created while file upload. Other methods of the app work great. It looks like blobstore is not responding for under 30 sec.
Any ideas why this happens?
Thanks!

Answer 1

Seems like you're not the only one having this issue:
http://groups.google.com/group/google-appengine/browse_thread/thread/27e52484946cbdc1#
(posted today)

Answer 2

Seems like Google had some reconfigurations of their servers. Now everything's working fine as it was before.

Answer 3

A runtime.DeadlineExceededError occurs when your request handler takes too long to execute - the blobstore call just happened to be what was running when that happened. You need to profile your handler with appstats to see why it's so slow.