Overpass API developpement

[Roland Olbricht <>]

Dear Etienne,

> Is it possible to have some numbers about overpass API ? I often have
> this kind of questions when I'm speaking about overpass and people tried
> to know the limit of overpass.

I would like to suggest the pages
http://prev.overpass-api.de/canvas.html
http://prev.overpass-api.de/canvas_requests.html
http://prev.overpass-api.de/canvas_bytes.html
http://prev.overpass-api.de/canvas_compressed.html

"prev" as in "previous" because they are from the old server. When 
moving is complete, they will have moved to "dev" (as "development") 
instead of "prev".

> How many queries per hours ? day ?
> How many users approximately ?
> How many seconds per query the server will work ?
> What is the maximum timeout ? What happened if we set a huge number in
> the timeout ? What happened if we don't set a timeout in the query ?
> When to know if a query is too big for the server ?

Please feel free to take screenshoots of the graph if it is useful. If 
you would like some of the numbers in a form suitable for libreoffice 
(or Excel), feel free to ask for it.

These are the (Javascript) tools I use to monitor for traffic anomalies.

The upper view is a graph printing numbers per day. In particular, 
canvas.html shows the number of unique IP addresses per day. 
canvas_requests.html shows the number of requests. canvas_bytes.html 
show the number of bytes generated for downloading, while 
canvas_compressed.html shows the number of bytes after transport 
compression.

It is a stacked graph, and the values are segmented by the amount of 
data downloaded per IP adress. Grey is below one kilobyte, black between 
1 KB and 10 KB, navy 10 KB to 100 KB and so on. The upper end is red for 
all IP adresses that have downloaded more than 1 GB.

The first combo box allows to select whether to include
- all requests
- requests "/api/interpreter?..."
- requests "/api/xapi?..."
- requests "/api/map?..."
- all remaining requests

The third box allows to turn the stacking order. The forth allows to 
enforce a certain vertical scaling. The fifth and sixth text field allow 
to set the date range. The last text field allows to smoothen over 
several days.

In the line below, the exact total figures are written. So if you want 
e.g. to know how much data for the "map?..." call has been downloaded 
from Canadian IP adresse in the last quarter of 2014, you can set the 
date range from "01/Oct/2014" to "31/Dec/2014" and select "map" in the 
first combo box and write "CA" in the second box.

> By the way, I'm the developer of the QuickOSM plugin for QGIS. Each
> queries has a parameter in the query string : info=QgisQuickOSMPlugin.
> Is it possible to have some stats about this tool ?

Well, this should be possible. In principle,
http://prev.overpass-api.de/canvas_user_agent.html
might be useful if the plugin reliably also sets a user agent. If that 
isn't enough, observing for the additional parameter should be possible 
to implement but hasn't high priority.

Best regards,

Roland