[Geomoose-users] Performance issues

[Dan Little]

To really get an advantage from tiling you'll need to setup a WMS TileCaching 
system, like oh..., TileCache. :)  Without doing that you'll be slowing the 
application down because MapServer will need to read the dataset, render the 
data, and return an image for EVERY tile requst.

This gets to be particularly noticeable when you're drawing things like water 
features as they have very complex boundaries.


----- Original Message ----
> From: Brent Fraser <bfraser at geoanalytic.com>
> To: Jeffrey Schmitz <jeffreykschmitz at gmail.com>
> Cc: geomoose-users at lists.sourceforge.net
> Sent: Mon, August 2, 2010 7:29:02 PM
> Subject: Re: [Geomoose-users] Performance issues
> 
> Jeff,
> 
>   I only started to look into WMS tiling, so I'm  guessing.  I expect that
> OpenLayers is requesting multiple images  (tiles) from mapserver instead
> of just one [larger] image.  If you had  some sort of file caching
> enabled on the server, you would see a performance  improvement
> (especially if your mapserver map files had only one or two  layers), as
> the file server would return the previously rendered image  instead of
> asking mapserver to [re]generate it.  Have a look at tilecache.org?
> 
> Brent
> 
> > Thanks  for the responses!
> >
> > We were using WMS for two reasons: we wanted  to make our data easily
> > accessible, and we wanted to take advantage of  tiling so that users
> > could move the map around without the need for it  to refresh
> > continually. This week, we tried disabling the tiling, and  performance
> > improved significantly, to be just about as quick as using  them as map
> > server layers. Any idea why tiling would create such a  drastic
> > decrease in performance?
> >
> > Also, our mapbook is  rather large (we have quite a few layers), so I
> > included a snippet of  what a typical map source entry looks like when
> > we use WMS with  tiling:
> >
> > <map-source name="hashed_layers" type="wms"  tiled="true"
> > queryable="false"  projection="EPSG:900913">
> >                  
<url>http://maps.glifwc.org/development/glifwc_wms.php</url>
> >                          <layer name="mn_bathymetric_contours"/>
> >                         <layer  name="cooperative_weed_management_areas"/>
> >                         <layer  name="eab_quarantine_counties"/>
> >                         <layer  name="minor_watersheds"/>
> >                         <layer  name="major_watersheds"/>
> >                         <layer  name="great_lakes_watersheds"/>
> >                 <param name="format" value="image/png"  />
> >                <param  name="TRANSPARENT" value="TRUE" />
> >         </map-source>
> >
> > Thanks again for the help!
> >  -Jeff
> >
> > On Tue, Jul 27, 2010 at 9:29 AM, Brent Fraser <bfraser at geoanalytic.com>
> >  wrote:
> >>  Are you using the same map file for both WMS and Mapserver  CGI?
> >>
> >>  While I've used mapserver as a WMS server to  produce a single image per
> >> request, I've never used it to produce  WMS tiles.  Can you give more
> >> details
> >> on your config?   What does your mapbook map-source entry look like?
> >>   What
> >> does the WMS CGI request(s) look like?
> >>
> >>  Best Regards,
> >> Brent Fraser
> >>
> >> Jeffrey Schmitz  wrote:
> >>>
> >>> Hey guys, I am having performance issues,  and was wondering if anyone
> >>> had any tips on how we could  possibly speed up our site. Our current
> >>>  setup:
> >>>
> >>> We have a postGIS table with data in  WGS84(EPSG:4326). It is defined
> >>> such in our mapfile layer  definitions, and projected by mapserver as
> >>> Web Mercator  (EPSG:900913) for web map services, which are served by
> >>>  geomoose.
> >>> Currently, with only a couple of layers turned on  (Wisconsin,
> >>> Minnesota and Michigan counties, and the great  lakes), our site takes
> >>> a LONG time to load (45seconds to a  minute). It appears to me that
> >>> this is an issue with our setup,  not network speed. If launched in
> >>> firefox, you can see that the  page loads fine, but is slow when
> >>> loading the wms tiles (you see  "waiting" for a while and then
> >>> "transferring"  for a couple  seconds, and then "waiting" again for
> >>> long  periods).
> >>>
> >>> We also have an identical site that  uses mapserver and mapfiles
> >>> directly instead of WMS, and it  loads in everything in just a couple
> >>> of  seconds.
> >>>
> >>> Does anyone have any suggestions as to  why we would be seeing such
> >>> significant slow down when using web  map services?
> >>>
> >>> Thanks for any  help!
> >>>
> >>>  Jeff
> 
> 
> 
> 
> 
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