Update Rust version to 1.51

[XAMPPRocky]

No description provided.

[markmandel]

Given that we are so performance bound - with changes like this (language versions, dependency upgrades etc) do we want to have a convention of some kind of performance comparison?

Even if it's a local performance test between the current and future Rust versions, just to show there aren't vastly different performance, memory or cpu differences?

[XAMPPRocky]

Given that we are so performance bound - with changes like this (language versions, dependency upgrades etc) do we want to have a convention of some kind of performance comparison?

I don’t have a strong opinion, except that we’d first need to have a reliable benchmark or set of benchmarks that can be easily tested by just running cargo bench or similar. Otherwise we and other contributors won’t end up doing it.

Also FWIW on upgrading Rust itself, severe performance regressions in the compiler don’t usually make it to stable, you can see in this graph compile times nearly always trend downwards

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[markmandel]

Just noting that we will need to update https://github.com/googleforgames/quilkin/blob/main/rust-toolchain.toml as well.

I expect no issue, but we could run through https://github.com/googleforgames/quilkin/blob/main/examples/iperf3/run.sh just as a quick "is everything reasonably fine" performance wise. (If I don't get to it while sitting in front of the TV this evening).

[markmandel]

Running iperf3 example on my laptop:

Rust v1.47.0

[SUM][RX-C]   0.00-60.00  sec  1.05 GBytes   150 Mbits/sec  0.000 ms  0/34350 (0%)  sender
[SUM][RX-C]   0.00-60.00  sec  1.05 GBytes   150 Mbits/sec  0.745 ms  0/34350 (0%)  receiver

Rust v1.51.0

[SUM][RX-C]   0.00-60.00  sec  1.05 GBytes   150 Mbits/sec  0.000 ms  0/34350 (0%)  sender
[SUM][RX-C]   0.00-60.00  sec  1.05 GBytes   150 Mbits/sec  0.761 ms  0/34350 (0%)  receiver

Throughput is exactly the same, and jitter is basically the same using the standard iperf3 test settings. So I say LGTM.

[markmandel]

Just noting that I built and uploaded the new CI step image.

If this ever gets painful, we should automate this.