Hey, good catch.

It looks like the high number of points is to try to get a more accurate
result when transforming the layer's native bounds to a GWC GridSet's CRS.
I guess the default 5 points rectangle can result in too much deformation
depending on the src to target transform.

In any case, I concurr 10k points could be too much, really not my area of
expertise, and it is tricky to automatically handle any layer. I'm ok with
your patch, since in the event someone experiences an actual issue there's
a work around.

Cheers,
Gabriel.



On Sun, Nov 11, 2018 at 11:07 AM Andrea Aime <andrea.a...@geo-solutions.it>
wrote:

> Hi,
> looking into build speed issues I've found a puzzling issue in GWC envelope
> reprojection code.
>
> Checking the profiles I've noticed there was a very high usage of
> reprojection code, which I've eventually
> tracked down to envelope reprojections here forcing 10000 points per
> envelope side during envelope
> reprojection (as opposed to the usual 5, used everywhere else):
>
>
> https://github.com/geoserver/geoserver/blob/master/src/gwc/src/main/java/org/geoserver/gwc/layer/GeoServerTileLayer.java#L960
>
> https://github.com/geoserver/geoserver/blob/master/src/gwc/src/main/java/org/geoserver/gwc/layer/GeoServerTileLayer.java#L987
>
> https://github.com/geoserver/geoserver/blob/master/src/gwc/src/main/java/org/geoserver/gwc/layer/GeoServerTileLayer.java#L993
>
> Going back to the default makes the build of the GWC module drop from 1:30
> to 1:00
> (I have other changes in the pipe to make it go down to 40s, to be
> discussed in a separate thread).
>
> The 10000 magic number dates back to a change made by Gabriel in 2012,
> titled
> "GEOS-4460: gwc integration to fully manage GeoServerTileLayer/Info throgh
> the CatalogConfiguration and external persistence"
>
> I could not find any reason for the 10k points. Going down to the normal 5
> breaks no tests, either.
> Anyone knows why such a high number is there, and if there is still any
> reason to use it?
>
> I've developed a change to use the default number of points per side,
> while allowing configuration via system variable, just in case, here:
> https://github.com/geoserver/geoserver/pull/3237
>
> If there are no known issues with the change, I'll open a ticket and make
> it ready for merge. Maybe we could merge only on
> master and see if someone pops up showing us a good reason for the change.
>
> Cheers
> Andrea
>
> ==
>
> GeoServer Professional Services from the experts! Visit
> http://goo.gl/it488V for more information. == Ing. Andrea Aime @geowolf
> Technical Lead GeoSolutions S.A.S. Via di Montramito 3/A 55054 Massarosa
> (LU) phone: +39 0584 962313 fax: +39 0584 1660272 mob: +39 339 8844549
> http://www.geo-solutions.it http://twitter.com/geosolutions_it
> ------------------------------------------------------- *Con riferimento
> alla normativa sul trattamento dei dati personali (Reg. UE 2016/679 -
> Regolamento generale sulla protezione dei dati “GDPR”), si precisa che ogni
> circostanza inerente alla presente email (il suo contenuto, gli eventuali
> allegati, etc.) è un dato la cui conoscenza è riservata al/i solo/i
> destinatario/i indicati dallo scrivente. Se il messaggio Le è giunto per
> errore, è tenuta/o a cancellarlo, ogni altra operazione è illecita. Le
> sarei comunque grato se potesse darmene notizia. This email is intended
> only for the person or entity to which it is addressed and may contain
> information that is privileged, confidential or otherwise protected from
> disclosure. We remind that - as provided by European Regulation 2016/679
> “GDPR” - copying, dissemination or use of this e-mail or the information
> herein by anyone other than the intended recipient is prohibited. If you
> have received this email by mistake, please notify us immediately by
> telephone or e-mail.*
> _______________________________________________
> Geoserver-devel mailing list
> Geoserver-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/geoserver-devel
>


-- 

Gabriel Roldán
Software Developer | Boundless <http://boundlessgeo.com/>
grol...@boundlessgeo.com
@boundlessgeo <http://twitter.com/boundlessgeo/>
_______________________________________________
Geoserver-devel mailing list
Geoserver-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-devel

Reply via email to