[OSM-dev] slow osm.org tile server

[Wolfram Schneider]

On Wed, 10 Apr 2019 at 08:56, Tom Hughes <tom at compton.nu> wrote:
>
> On 09/04/2019 19:39, Wolfram Schneider wrote:
> > On Mon, 25 Mar 2019 at 18:16, Wolfram Schneider <wosch at freebsd.org> wrote:
> >>
> >> Hi,
> >>
> >> I noticed that the standard OSM tile servers
> >> (N.tile.openstreetmap.org) are currently slow.
> >>
> >> On the site
> >>
> >>    https://mc.bbbike.org/mc/
> >>
> >> you will see that OSM is the slowest, and takes at least 5 seconds to
> >> get all tiles. The other servers responses in less than a second.
> >>
> >> Downloading a single tile is also always slow:
> >>
> >> curl https://b.tile.openstreetmap.org/11/1100/671.png >/dev/null
> >>    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
> >>                                   Dload  Upload   Total   Spent    Left  Speed
> >> 100 41017  100 41017    0     0   7658      0  0:00:05  0:00:05 --:--:--  7146
> >>
> >> it seems that there is a delay of 5 seconds until the tile is fully
> >> delivered, and the download rate is at 7Kbyte/s. I tried this from
> >> different locations (Bay Area, NYC, Germany) - the result is always
> >> the same.
> >
> > it was better in the last week, down to 2-3 seconds. But not it is
> > slow as hell again and takes more than 6.5 seconds to fetch a single
> > tile:
> >
> > time curl -sSf https://c.tile.openstreetmap.org/11/1100/671.png >/dev/null
> > real 0m6.587s
> > user 0m0.017s
> > sys 0m0.009s
> >
> > you can repeat the request and it is still slow (5+ seconds).
> >
> > who is in charge of the HTTPS setup for OSM?
>
> Using curl like that will be slow beause you are being put
> in a deliberate slow lane when not coming via the web site.

I first noticed the slow tile servers while visiting the main web site
https://www.openstreetmap.org using a browser. It didn't matter which
browser I used, Safari, Firefox, Google Chrome etc. This was more than
4 weeks ago. Changing the user agent does not speedup anything. You
can use an empty user agent, a random user agent ("foobar") or a real
one, same results. If there is a slow lane, then apparently all user
agent are effected.

Google Chrome reports a page load time of 7 seconds for
https://www.openstreetmap.org which is notable slow and you don't want
use in a presentation or show your mom. If you move the slippymap, it
will takes another 5 seconds.

In contrast, the OpenCycleMap https://www.opencyclemap.org loads in
less than a second (!). For me, both tile servers
(https://a.tile.openstreetmap.org/ and
https://a.tile.thunderforest.com/cycle) are running at the same data
center at hetzner.com (ping time < 20ms). It is unlikely a provider
issue.

I run the tests from different locations (US West, US East, Germany,
Finland) and different providers (Yahoo, Alibaba, Hetzner, Vodafone,
Telefonica) - same results. Big providers may have network slowdowns,
but they usually fix this in minutes or hours.

My gut feeling is that something is wrong with the SSL setup at
tile.openstreetmap.org. Feel free to contact me if you have any
question.

-Wolfram


>
> Tom
>
> > -Wolfram
> >
> >
> >> PS: if I do not use HTTPS and instead plain old HTTP, it will take
> >> only 0.3 - 0.6 seconds.
> >>
> >> Any idea whats wrong with the HTTPS setup for the tile servers?
> >>
> >> -Wolfram
> >> --
> >> Wolfram Schneider <wosch at FreeBSD.org> https://wolfram.schneider.org
> >> Planet.osm extracts: https://extract.bbbike.org
> >> BBBike Map Compare: https://mc.bbbike.org/mc
> --
> Tom Hughes (tom at compton.nu)
> http://compton.nu/
-- 
Wolfram Schneider <wosch at FreeBSD.org> https://wolfram.schneider.org