Files
neon/test_runner/fixtures/parametrize.py
Christian Schwarz 8075f0965a fix(test suite) virtual_file_io_engine and get_vectored_impl patametrization doesn't work (#7113)
# Problem

While investigating #7124, I noticed that the benchmark was always using
the `DEFAULT_*` `virtual_file_io_engine` , i.e., `tokio-epoll-uring` as
of https://github.com/neondatabase/neon/pull/7077.

The fundamental problem is that the `control_plane` code has its own
view of `PageServerConfig`, which, I believe, will always be a subset of
the real pageserver's `pageserver/src/config.rs`.

For the `virtual_file_io_engine` and `get_vectored_impl` parametrization
of the test suite, we were constructing a dict on the Python side that
contained these parameters, then handed it to
`control_plane::PageServerConfig`'s derived `serde::Deserialize`.
The default in serde is to ignore unknown fields, so, the Deserialize
impl silently ignored the fields.
In consequence, the fields weren't propagated to the `pageserver --init`
call, and the tests ended up using the
`pageserver/src/config.rs::DEFAULT_` values for the respective options
all the time.

Tests that explicitly used overrides in `env.pageserver.start()` and
similar were not affected by this.

But, it means that all the test suite runs where with parametrization
didn't properly exercise the code path.

# Changes

- use `serde(deny_unknown_fields)` to expose the problem  
- With this change, the Python tests that override
`virtual_file_io_engine` and
`get_vectored_impl` fail on `pageserver --init`, exposing the problem.
- use destructuring to uncover the issue in the future
- fix the issue by adding the missing fields to the `control_plane`
crate's `PageServerConf`
- A better solution would be for control plane to re-use a struct
provided
    by the pageserver crate, so that everything is in one place in
    `pageserver/src/config.rs`, but, our config parsing code is (almost)
    beyond repair anyways.
- fix the `pageserver_virtual_file_io_engine` to be responsive to the
env var
  - => required to make parametrization work in benchmarks

# Testing

Before merging this PR, I re-ran the regression tests & CI with the full
matrix of `virtual_file_io_engine` and `tokio-epoll-uring`, see
9c7ea364e0
2024-03-14 11:18:55 +00:00

63 lines
1.8 KiB
Python

import os
from typing import Optional
import pytest
from _pytest.python import Metafunc
from fixtures.pg_version import PgVersion
"""
Dynamically parametrize tests by different parameters
"""
@pytest.fixture(scope="function", autouse=True)
def pg_version() -> Optional[PgVersion]:
return None
@pytest.fixture(scope="function", autouse=True)
def build_type() -> Optional[str]:
return None
@pytest.fixture(scope="function", autouse=True)
def platform() -> Optional[str]:
return None
@pytest.fixture(scope="function", autouse=True)
def pageserver_virtual_file_io_engine() -> Optional[str]:
return os.getenv("PAGESERVER_VIRTUAL_FILE_IO_ENGINE")
def pytest_generate_tests(metafunc: Metafunc):
if (bt := os.getenv("BUILD_TYPE")) is None:
build_types = ["debug", "release"]
else:
build_types = [bt.lower()]
metafunc.parametrize("build_type", build_types)
if (v := os.getenv("DEFAULT_PG_VERSION")) is None:
pg_versions = [version for version in PgVersion if version != PgVersion.NOT_SET]
else:
pg_versions = [PgVersion(v)]
metafunc.parametrize("pg_version", pg_versions, ids=map(lambda v: f"pg{v}", pg_versions))
# A hacky way to parametrize tests only for `pageserver_virtual_file_io_engine=std-fs`
# And do not change test name for default `pageserver_virtual_file_io_engine=tokio-epoll-uring` to keep tests statistics
if (io_engine := os.getenv("PAGESERVER_VIRTUAL_FILE_IO_ENGINE", "")) not in (
"",
"tokio-epoll-uring",
):
metafunc.parametrize("pageserver_virtual_file_io_engine", [io_engine])
# For performance tests, parametrize also by platform
if (
"test_runner/performance" in metafunc.definition._nodeid
and (platform := os.getenv("PLATFORM")) is not None
):
metafunc.parametrize("platform", [platform.lower()])