High replication delete delay in local server

Question

I have this code using Python with --high_replication --use_sqlite:

def delete(self, id):
    product = Product.get_by_id(long(id))
    if product is None:
        self.session.add_flash('Product could not be found', level='error')
        self.redirect_to('products')
    else:
        product.key.delete()
        self.session.add_flash('Product is deleted')
        self.redirect_to('products')

After the delete I redirect to the 'products' page which is basically a page querying all Products and displaying them.

The only thing I found out is that it is displaying the deleted record as well. When I refresh the 'products' page then the record is gone.

Are others facing this as well and is there something I can do?

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Edit1:

I'm seeing this behaviour only local btw, on production infrastructure this is not the case. I solved this in the past for the Java sdk using the following jvm arg:

-Ddatastore.default_high_rep_job_policy_unapplied_job_pct=20

Does Python sdk has something similar to simulate the amount of eventual consistency you want your application to see locally?

See https://developers.google.com/appengine/docs/java/tools/devserver

Answer 1

What you're seeing is the eventual consistency behavior of the HRD datastore, which the devserver simulates.

https://developers.google.com/appengine/docs/python/datastore/queries#Data_Consistency

In an eventually consistent query, the indexes used to gather the results are also accessed with eventual consistency. Consequently, such queries may sometimes return entities that no longer match the original query criteria, while strongly consistent queries are always transactionally consistent.