id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
7682	"WMS-cache does not ""tile"" requests one same boundaries between session resulting in re-requests of already cached areas"	jjaf.de	team	"WMS does pre-load cached areas but since
{{{#!java
cache.hasExactMatch()
}}}
is false since the viewport is slighty shifted although the complete area can be rendered the whole area is re-requested from WMS-server

=== Problem ===

Re-requests are resulting in having a huge cache of [session]-times the size and stress on network and WMS-server.

=== possible Solution ===

A solution could be to introduce ""tiling"" in maybe
{{{#!java
downloadAreaToCache()
}}}
so that the same bounding-boxes for WMS-requests having shifted viewports are being calculated between sessions or have an algorithm to recognise total coverage from cache instead of
{{{#!java
cache.hasExactMatch()
}}}
I would suggest the former is easier to implement maybe with help from the tiling-projection.

=== Workaround ===

Set viewport to exactly same coordnates and zoom before adding WMS-layer with cache e.g. by using ""Jump To Position""."	defect	closed	normal	15.08	Core imagery	tested	fixed	WMS cache hasExactMatch tiling	jttt