Compared performance of Varnish Cache on x86_64 and aarch64

[Martin Grigorov]

On Wed, Jul 29, 2020 at 3:11 PM Poul-Henning Kamp <phk at phk.freebsd.dk>
wrote:

> --------
> Martin Grigorov writes:
>
> > > > Any feedback and ideas how to tweak it (VCL or even patches) are very
> > > > welcome!
> > >
> > > First you need to tweak your benchmark setup.
> > >
> > >    aarch64
> > >
> > >           Thread Stats   Avg      Stdev     Max   +/- Stdev
> > >             Latency   655.40us  798.70us  28.43ms   90.52%
> > >
> > > Strictly speaking, you cannot rule out that the ARM machine
> > > sends responses before it receives the request, because your
> > > standard deviation is larger than your average.
> > >
> >
> > Could you explain in what case(s) the server would send responses before
> > receiving a request ?
>
> It never would, that's the point!
>
> Your measurement says that there is 2/3 chance that the latency
> is between:
>
>         655.40µs - 798.70µs     = -143.30µs
>
> and
>         655.40µs + 798.70µs     = 1454.10µs
>
> You cannot conclude _anything_ from those numbers.
>

This now sounds like: if the latency stats are not correct then most
probably the throughput is also not correct!
I may switch to a different load client tool!


>
>
> --
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk at FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
>
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