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I am trying to migrate an application from django 1.11.1 to django 2.0.1
Tests are set up to run with sqlite in memory database. But every test is failing, because sqlite3.OperationalError: database table is locked for every table. How can I find out why is it locked? Icreasing timeout setting does not help.
I am using LiveServerTestCase, so I suppose the tests must be running in a different thread than the in memory database, and it for some reason does not get shared.
Answer
I hit this, too. The LiveServerTestCase is multi-threaded since this got merged.
It becomes a problem for me when my app under test issues multiple requests. Then, so my speculation, the LiveServer spawns threads to handle those requests. Those requests then cause a write to the SQLite db. That in turn does not like multiple writing threads.
Funnily enough, runserver knows about --nothreading. But such an option seems to be missing for the test server.
The following snippet brought me a single-threaded test server:
class LiveServerSingleThread(LiveServerThread):
"""Runs a single threaded server rather than multi threaded. Reverts https://github.com/django/django/pull/7832"""
def _create_server(self):
"""
the keep-alive fixes introduced in Django 2.1.4 (934acf1126995f6e6ccba5947ec8f7561633c27f)
cause problems when serving the static files in a stream.
We disable the helper handle method that calls handle_one_request multiple times.
"""
QuietWSGIRequestHandler.handle = QuietWSGIRequestHandler.handle_one_request
return WSGIServer((self.host, self.port), QuietWSGIRequestHandler, allow_reuse_address=False)
class LiveServerSingleThreadedTestCase(LiveServerTestCase):
"A thin sub-class which only sets the single-threaded server as a class"
server_thread_class = LiveServerSingleThread
Then, derive your test class from LiveServerSingleThreadedTestCase instead of LiveServerTestCase.