Hi,
I have some code that queues up a task inside *_post_put_hook*.
The task retrieves the key and fetches the entity. However sometimes the
worker fails because the object for that key hasn't been created yet, but
will succeed when it next runs.
Note that we're retrieving the object by key, so I expect the data to be
consistent.
I want to understand WHY the object isn't available. I'm only calling the
enqueue on commit, but it seems this isn't always working.
Below is the example code which does the committing of the entity.
@ndb.synctasklet
def log_usage(self):
@ndb.transactional_tasklet(xg=True)
def _txn():
# some other stuff happens here, but trying to make this example as
simple as possible.
yield Log.insert_document_log_async()
yield _txn()
class Log(ndb.Expando):
@classmethod
@ndb.tasklet
def insert_document_log_async(cls):
log = cls()
logging.debug("insert document log in transaction:
{}".format(ndb.in_transaction()))
yield log.put_async()
@ndb.synctasklet
def _post_put_hook(self, future):
@ndb.synctasklet
def _callback_on_commit():
key = future.get_result()
yield SqlTaskHelper.enqueue_syncronise_sql_model_async(key)
logging.debug("_post_put_hook In transaction:
{}".format(ndb.in_transaction()))
ndb.get_context().call_on_commit(lambda: _callback_on_commit())
1. *log_usage *is called.
2. When calling *insert_document_log_async* logging indicates that we're
in a transaction (insert document log in transaction: *True*).
3. But the post put hook* _post_put_hook* In transaction: *False *(so
call_on_commit is executed immediately). The task runs shortly after an
occasional fails.
Can someone please shed some light on where the problem is?
Thanks
Rob
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