| From: | Francisco Olarte <folarte(at)peoplecall(dot)com> |
|---|---|
| To: | f(dot)venchiarutti(at)ocado(dot)com |
| Cc: | "pgsql-generallists(dot)postgresql(dot)org" <pgsql-general(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Network performance optimization |
| Date: | 2020-09-09 17:18:48 |
| Message-ID: | CA+bJJbyE8voBqJ3Ytjjrbxh5SEcvMhdffqtPRMyvXWqLyv7KaA@mail.gmail.com |
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| Lists: | pgsql-general |
Fabio:
On Wed, Sep 9, 2020 at 1:05 PM Fabio Ugo Venchiarutti
<f(dot)venchiarutti(at)ocado(dot)com> wrote:
> Even if network datagrams moved at the speed of light and with no
> serialisation/forwarding delay (which they don't), you're still going to
> deal with several thousand KMs of distance; I'm positively surprised
> you're getting such short round-trip times as it stands.
Light travels at about a foot per nanosecond in air/vacuum, 20 cm per
nanosecond in glass IIRC, so you can RTT 10cm per nanosecond in fiber.
This amounts to 100km per millisecond. 1200 to 1600 km in 12-16 ms.
East-1/2 are N.Virginia / Ohio, which can be from 240 to 950 km apart
( on a quick google maps measure, not several thousands ), depending
on the exact place. And Amazon has really fast pipes going between
their regions, so this is not surprising. I have 55ms from ireland (eu
west 1) to N.Virg., and they are 5500 km over the great circle.
Francisco Olarte.
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