Pytest Xdist parallel execution, prevent recreating the database

4
votes

I'm trying to speed up the Selenium tests in my python Django web application by using parallel execution of 4 threads (-n=4)

Of the first 4 tests, 3 give the following error:

[test setup] [Test Error Output]
Got an error creating the test database: (1007, "Can't create database 'test1database'; database exists")

I get that I have to specify setup to be run once before parallel test execution, to prevent this multiple attempts at creating the database, but how would I enforce this in pytest xdist configuration?

2
seleniumpytestxdistpytest-xdist

2 Answers

4
votes

You can probably have a different database for each one of the threads. The worker_id fixture allows you to do that https://github.com/pytest-dev/pytest-xdist#identifying-the-worker-process-during-a-test

@pytest.fixture()
def test_database(worker_id):
    return CreateDatabase("test{}database".format(worker_id))

Update

This github issue comment shows a solution to the OP's original problem. It also creates N databases, using a shared template. This brings the interesting twist of synchronizing the access to a shared resource in fixture.

0
votes

You can use this if you won't be stuck in any problem in the rest of your code:

CREATE DATABASE IF NOT EXISTS test1database;