[mapserver-users] Re: WMS and tiles cutting off

Mon May 3 14:37:20 EDT 2010

[Mon May  3 11:35:28 2010].1406 msDrawMap(): Drawing Label Cache, 0.000s
[Mon May  3 11:35:28 2010].132164 msDrawMap() total time: 0.136s
[Mon May  3 11:35:28 2010].511199 msSaveImage() total time: 0.379s
[Mon May  3 11:35:28 2010].511596 mapserv request processing time (msLoadMap
not
 incl.): 0.533s
[Mon May  3 11:35:28 2010].511607 msFreeMap(): freeing map at 0x128c9cc0.
[Mon May  3 11:35:31 2010].519338 msDrawMap(): Layer 1 ((null)), 0.173s
[Mon May  3 11:35:31 2010].519495 msDrawMap(): Drawing Label Cache, 0.000s
[Mon May  3 11:35:31 2010].519507 msDrawMap() total time: 0.179s
[Mon May  3 11:35:32 2010].564206 msSaveImage() total time: 1.045s
[Mon May  3 11:35:32 2010].564672 mapserv request processing time (msLoadMap
not
 incl.): 1.233s
[Mon May  3 11:35:32 2010].564683 msFreeMap(): freeing map at 0x15534cb0.

Seems pretty clear the problem is msSaveImage().  Not really sure what to do
to fix this.

On Mon, May 3, 2010 at 2:05 PM, Fawcett, David (MPCA) <
David.Fawcett at state.mn.us> wrote:

>  Adam,
>
>
>
> It sounds like you have already enabled debug mode, if now, you should be
> able to get the rendering time from the output.
>
>
>
> David.
>
>
>
> *From:* Adam Eskreis [mailto:aeskreis at gmail.com]
> *Sent:* Monday, May 03, 2010 1:02 PM
> *To:* Fawcett, David (MPCA)
> *Cc:* Lime, Steve D (DNR); mapserver-users at lists.osgeo.org
>
> *Subject:* Re: [mapserver-users] Re: WMS and tiles cutting off
>
>
>
> Thank you for the response David.
>
> I have optimized the query all I can.  I have optimized the query to the
> point that even with all categories selected, the query has a run time of 52
> ms.  I can only assume that the issue lies with the generation of the
> images.  I will try to run it without the "IN" part of the query, but I
> can't imagine that it'st he problem.  I think the problem is that there are
> a large number of symbols that need to be generated, and it's taking
> mapserver a long time to load them in.  Also, yes I have indexes on all
> columns that I am calling in, and yes, they are all using the same SRS.  I
> am still trying a few more things, but I don't think it's the database query
> that's causing the problem.
>
>  On Fri, Apr 30, 2010 at 9:37 AM, Fawcett, David (MPCA) <
> David.Fawcett at state.mn.us> wrote:
>
> Adam,
>
>
>
> It sounds like you have boiled the issue down to too much of a time lag
> between the time the query is executed and the image appears in the client.
>
>
>
>
> Is it taking a long time for MapServer to draw the image, or is it the
> delivery of the image to the requesting machine and subsequent placement in
> the client?
>
>
>
> If it is taking MapServer a long time, maybe there are some more data
> optimizations that you can do.  Is there a better way to structure your
> data, can you do any pre-processing?  Is it all in the same SRS, got
> attribute and spatial indexes?  I have used the SQL IN for some apps with
> reasonable performance, but in the last 6 months or so, there were some
> posts on this list comparing the use of IN to a layer (or class?) filter.
> The latter solution was significantly faster.
>
>
>
> If it is taking a long time to get to the client, then that is likely an
> infrastructure issue on either end.
>
>
>
> If you want some more help digging in more deeply, post some more stats and
> mapfile snippets.
>
>
>
> David.
>
>
>
> *From:* mapserver-users-bounces at lists.osgeo.org [mailto:
> mapserver-users-bounces at lists.osgeo.org] *On Behalf Of *Adam Eskreis
> *Sent:* Thursday, April 29, 2010 4:24 PM
> *To:* Lime, Steve D (DNR)
> *Cc:* mapserver-users at lists.osgeo.org
>
>
> *Subject:* Re: [mapserver-users] Re: WMS and tiles cutting off
>
>
>
> I tried doing ratio:1 unfortunately it doesn't seem like enough of a
> performance increase.  Separate layers for each category is an option,
> however, there are over a hundred categories, and any combination of
> categories can be on at any given time, so this could prove to have
> performance issues of it's own.  However, I thank you guys Steve and Kaipi
> for your advice.  I think I am just going to go back to my old method, which
> was using php mapscript to generate the tiles, then each time the user
> selected new categories, purge the cache and remake the mapfile.  It's not
> the ideal solution but it seems to be the only one.
>
> Thanks again,
>
> -Adam
>
> On Thu, Apr 29, 2010 at 3:50 PM, Lime, Steve D (DNR) <
> Steve.Lime at state.mn.us> wrote:
>
> Note that by default I believe openlayers will request an image that is
> *much* larger than what is visible. Setting the layers (OL) ratio:1 makes it
> the same size as the view port and that can speed up rendering considerably.
>
> Alternatively you could create a separate set of tiles for each category I
> suppose and switch OL layers as necessary...
>
>
> Steve
>
> ________________________________________
> From: mapserver-users-bounces at lists.osgeo.org [
> mapserver-users-bounces at lists.osgeo.org] On Behalf Of Adam Eskreis [
> aeskreis at gmail.com]
>
> Sent: Thursday, April 29, 2010 2:25 PM
>
> To: mapserver-users at lists.osgeo.org
> Subject: Re: [mapserver-users] Re: WMS and tiles cutting off
>
> Ok, I just gave an untiled layer a try, unfortunately though, due to the
> large amount of symbols being displayed on the screen, there is about a 2
> second delay every time the map is panned.  My client will most certainly
> find this unacceptable.  I have tried using smaller images, but I cannot
> sacrifice any more quality.  I believe my database query to be as optimized
> as it can be (has about 50 ms runtime, I honestly don't think I can get it
> any lower than that).
>
> If these are the only options, is there something else besides WMS that you
> all would recommend using to solve this issue?
>
> Thanks,
> -Adam
>
> On Thu, Apr 29, 2010 at 2:54 PM, Lime, Steve D (DNR) <
> Steve.Lime at state.mn.us<mailto:Steve.Lime at state.mn.us>> wrote:
> So use two layers. One for the background, use tilecache for that. Then use
> an untiled wms/mapserver layer for the overlayed points. - Steve
> ________________________________________
>
> From: mapserver-users-bounces at lists.osgeo.org<mailto:
> mapserver-users-bounces at lists.osgeo.org> [
> mapserver-users-bounces at lists.osgeo.org<mailto:
> mapserver-users-bounces at lists.osgeo.org>] On Behalf Of Adam Eskreis [
> aeskreis at gmail.com<mailto:aeskreis at gmail.com>]
>
> Sent: Thursday, April 29, 2010 1:24 PM
>
> To: mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org
> >
>
> Subject: Re: [mapserver-users] Re: WMS and tiles cutting off
>
> I have thought about using tilecache with metatiling, however there is a
> caveat about this map that i forgot to mention in my main post, and it has
> to do with that "categories" parameter.  Basically, each point/symbol on the
> map has an associated category in the database backend.  I am using
> mapserver/WMS parameters to change the categories which are called.  Each
> time the user selects a category, only the points in that category are
> shown.  My query in the mapfile looks something like thi:
>
> SELECT point_geom,gid,symbol,angle FROM mapdata WHERE category
> IN(%CATEGORIES%)";
>
> And each time the user changes the categories, I use openlayers to merge
> new parameters, and input the new category values that should be used.  Is
> tilecache still useable if I have a system like this set up?
>
> Thanks,
> -Adam
>
> On Thu, Apr 29, 2010 at 6:14 AM, kaipi <mapcollect at gmx.net<mailto:
> mapcollect at gmx.net><mailto:mapcollect at gmx.net<mailto:mapcollect at gmx.net>>>
> wrote:
>
> Hi,
>
> you can use  http://tilecache.org/ Tilecache   with the option metatiling
> enabled. With metatiling enabled Tilecache will fetch larger tiles (eg.
> 4096x4096) from Mapserver and will cut them into smaller tiles (eg.
> 256x256). It will also increase performance because Mapserver does not need
> to render tiles when they are already in cache.
>
> kaipi
> --
> View this message in context:
> http://osgeo-org.1803224.n2.nabble.com/WMS-and-tiles-cutting-off-tp4978418p4979280.html
> Sent from the Mapserver - User mailing list archive at Nabble.com.
> _______________________________________________
> mapserver-users mailing list
>
> mapserver-users at lists.osgeo.org<mailto:mapserver-users at lists.osgeo.org
> ><mailto:mapserver-users at lists.osgeo.org<mailto:
> mapserver-users at lists.osgeo.org>>
>
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-users/attachments/20100503/c95b2693/attachment-0001.html