Hi Georg,
When NCSS finishes creating the subset result (in the cache directory, as
you say), the binary data is then immediately written to the server's
response stream. No information about the file's location within the cache
directory is transmitted.
It could definitely be a useful addition to THREDDS to support this kind of
request; plenty of people besides you run THREDDS behind a proxy server.
Perhaps you can add an issue for the feature on our GitHub repo? [1] I
can't make any predictions about when we'll be able to get to it, but pull
requests are always welcome!
Cheers,
Christian
[1] https://github.com/Unidata/thredds/issues
On Wed, Jul 12, 2017 at 8:10 AM, Georg Seyerl <georg.seyerl@xxxxxxxxxx>
wrote:
> Hi,
> first of all, nice work, I really like thredds.
>
> We try to implement a data repository for climate data.
> As data catalogue we use ckan. As webserver we use nginx with
> reverse-proxies to uwsgi(ckan python application server) and
> tomcat(thredds).
>
> I wrote a small python proxy with some authorization checks to access
> the thredds server. The goal is to make new subsets citable and
> recallable. The WMS service works flawlessly with
> https://www.nginx.com/resources/wiki/start/topics/examples/xsendfile/
> so that the response is directly served via nginx instead of blocking a
> worker of my application server.
>
> For the ncss part I'd like to calculate a hash sum for the subset and
> rename it before passing it back to the user. It would be nice if I
> could access the cache of ncss directly from my python application to do
> this. I was thinking about a job making the call to thredds, process
> everything, change the Content-Disposition and return the file via
> xsendfile and nginx again.
>
> To sum up, is it possible to get a response(including the relative
> filepath from the cache directory) from the thredds server when the
> subset creation process is done. Can I serve the file with another stack
> and wait for the deletion process due to my maxAge setting.
> Is it even worth thinking about it or is it best to send the http
> request from my python application server to thredds without touching
> the cache.
>
> Thank you in advance and best regards,
> Georg
>
>
> --
> Georg Seyerl
> Data Scientist / Architect
> Department Data, Methods, Models
> CCCA Data Centre
> Central Institute for Meteorology and Geodynamics
> 1190 Vienna, Hohe Warte 38 (Austria/Europe)
> Tel.: +43 1 36026 2512
> E-Mail: georg.seyerl@xxxxxxxxxx
> Homepage: www.ccca.ac.at
>
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