[Geocoding] Removing HTTP (man in the middle) for performance

[Sarah Hoffmann]

Hi Mark,

On Tue, Apr 30, 2019 at 07:59:13AM +0300, Mark Davies wrote:
> Hi All
> 
> Following on from some excellent advice from Sarah Hoffmann, I have been
> able to increase the server to handle a greater amount of requests per
> second
> 
> I have now noticed the app that requests reverse geo-code is the bottle
> neck, and after a bunch of tests it appears the time it takes to return the
> result is the biggest issue (limiting concurrent threads)
> Therefore I need to reduce the amount of time it takes nominatim to return
> the result

If the limited number of concurrent threads is the bottleneck,
then I would look into that first. Or think about buying a
second machine.

> 
> From my tests it takes around 270-500ms for the calling app to get the
> result, I've searched online and seen Sarah also mention the HTTP portion
> "main in the middle" is the biggest slow down.
> So my question is: what options do I have to cut out the man in the middle,
> the HTTP portion?

Sounds rather like a network problem to me which you are trying
to fix on the wrong end.

> 
> The calling server/app is windows 2016/ .Net App, and its not an option for
> everything to go on one server, but I plan to move it on a LAN, currently
> its hitting public IP
> 
> Some of my thoughts on cutting out the HTTP portion was
> 1. Host the reverse php code on windows, connect the windows php code to
> nominatim DB (all on LAN)

The Nominatim DB would still need to run on a different server because
it needs to run under Linux. So this solution hardly cuts network traffic.

> 2. connect to DB directly from windows, and do same DB query as nominatim

Same problem. And you will find that there is no single query you can
run.


Sarah