Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

test(transport): assert maximum bandwidth on gbit link #2203

Open
wants to merge 1 commit into
base: main
Choose a base branch
from

Conversation

mxinden
Copy link
Collaborator

@mxinden mxinden commented Oct 26, 2024

This commit adds a basic smoke test using the test-fixture simulator, asserting the expected bandwidth on a 1 gbit link.

Given #733, the current expected bandwidth is limited by the fixed sized stream receive buffer (1MiB), not by the bandwidth of the link.

While a bit unconventional, I think it is worth having this smoke test, to make sure we don't regress. What do folks think?

This commit adds a basic smoke test using the `test-fixture` simulator,
asserting the expected bandwidth on a 1 gbit link.

Given mozilla#733, the current expected bandwidth
is limited by the fixed sized stream receive buffer (1MiB).
#[allow(clippy::cast_precision_loss)]
fn gbit_bandwidth() {
const MIB: usize = 1024 * 1024;
const TRANSFER_AMOUNT: usize = 100 * MIB;
Copy link
Collaborator Author

@mxinden mxinden Oct 26, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Takes ~2s to run on my machine, 1s for up-, 1s for download. Using < 100 MIB doesn't give me consistent results.

Worth spending 2s of our unit-test runtime on this?

(Not to be confused with simulated time.)

//
// Tracked in https://github.com/mozilla/neqo/issues/733.
let maximum_bandwidth = MIB as f64 * 8.0 / 0.1; // bandwidth-delay-product / delay = bandwidth
let expected_utilization = 0.5;
Copy link
Collaborator Author

@mxinden mxinden Oct 26, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Running this test in a loop, Neqo is not able to utilize more than ~50% of the maximum bandwidth of 80 Mbit/s. Intuitively, even with packet loss, I would expect a congestion controller to be able to saturate more than 50% of a link.

45.95196838717057
49.31818797697269
45.826026606578566
49.53933723888579
45.997472274917506
49.31788343565587
45.58981370339061
49.31818797697269
40.48485804428038
49.451830153095756
40.5585726298109
49.31793477754305
40.55224164532084
54.71429614593755
45.57110592947965
49.45192167242847
40.53596208031323
54.79092558021697
45.95144831798395

I will look for mistakes in my math with a fresh mind tomorrow.

pub const fn gbit_link() -> Self {
let rate = 1_000_000_000 / 8;
let delay = Duration::from_millis(50);
let capacity = rate / 20; // rate * 0.05
Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Simply the bandwidth-delay-product. Happy for more realistic suggestions.

Copy link

Failed Interop Tests

QUIC Interop Runner, client vs. server

neqo-latest as client

neqo-latest as server

All results

Succeeded Interop Tests

QUIC Interop Runner, client vs. server

neqo-latest as client

neqo-latest as server

Unsupported Interop Tests

QUIC Interop Runner, client vs. server

neqo-latest as client

neqo-latest as server

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant