how to speed up MapServer performance?
Stuart Eve
stuarteve at LPARCHAEOLOGY.COM
Tue May 16 12:15:45 EDT 2006
We've done some benchmarking for our own system heres some conclusions
that you could think about (sorry if these are repeats I just cut and
paste straight from our dev wiki):
*Conclusions*
* The geographic size of the area being displayed makes a difference
to processing performance - i.e. if you trying to display the
whole of europe in one hit (with detailed vectors)
* Rasters (despite having large file sizes and being of high
resolution) seem to make very little difference to performance. It
is good practice to create overviews, tile and pre-project into
the desired coordinate system.
* Pre-projecting the layers into the desired coordinate system seems
to make a difference (as the worst performing layers were all in
UTMs being reprojected in 3034) - however this needs to be tested
further as a number of the other layers were in LatLongs and they
seemed to make no impact on performance. *UPDATE: * This has now
been tested with the comune being pre-projected into 3034 - and
being displayed at all scales. Previosuly this gave a hit of
*+23s* when it was in 32633 - when pre-projected into 3034 it only
gave a hit of *0.5s*! Pre-projection is clearly an absolute priority.
* Only turn layers on if they are absolutely needed (make sure that
min/maxscales are used properly).
* the complexity of the vector layers appears to make a difference,
so in some cases, it may be worth making simplified shapefiles for
use when zoomed out - and only use the most detailed ones when
zoomed in enough to be able to see the complicated bits. Also you
can create *.qix files.
Hope it helps
Stuart
Doyon, Jean-Francois wrote:
> Well, I don't have any for Mapserver itself, but I'm sure you'll find
> plenty for Apache, and it's processes vs. thread issues. Apache was
> never an option for windows because of its forking model ... creating
> processes dynamically on windows was too slow and expensive. When
> Apache went to MPM's and supported a threaded model, things got much
> better.
>
> Everything in windows is designed to be low on process creation, and
> thread heavy ... Including windows itself. This is not a putdown,
> it's just a reality. Linux has cheap processes, Windows has cheap
> threads.
>
> As such, CGI is more expensive on Windows. But of course, there
> admitedly might be other speed gains elsewhere along the line (IIS
> being in kernel space, and threaded) to compensate. I suppose you
> could compare with Apache on windows?
>
> Doesn't change the fact that what I said is true :P But yeah, I'm
> maybe being a little too purist here ;)
>
> J.F.
>
> ------------------------------------------------------------------------
> *From:* Ed McNierney [mailto:ed at topozone.com]
> *Sent:* May 16, 2006 10:03 AM
> *To:* Doyon, Jean-Francois; MAPSERVER-USERS at LISTS.UMN.EDU
> *Subject:* RE: [UMN_MAPSERVER-USERS] how to speed up MapServer
> performance?
>
> J.F. -
>
> I was with you all the way until you mentioned operating systems!
> There's no reason to think that Zhonghai's operating system is at all
> related to his problem, and it's dangerous to propagate operating
> system myths. I run lots of MapServer machines on Windows and Linux
> (mostly Linux) and I cannot find any evidence (after 5 years or so)
> that there's any difference worth thinking about on identical hardware.
>
> If you can show me a MapServer test with identical configurations on
> identical hardware showing statistically significant differences in
> performance when running Window vs. Linux, I'd love to see the details.
>
> - Ed
>
> Ed McNierney
> President and Chief Mapmaker
> TopoZone.com / Maps a la carte, Inc.
> 73 Princeton Street, Suite 305
> North Chelmsford, MA 01863
> Phone: +1 (978) 251-4242
> Fax: +1 (978) 251-1396
> ed at topozone.com
>
>
> ------------------------------------------------------------------------
> *From:* UMN MapServer Users List
> [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] *On Behalf Of *Doyon, Jean-Francois
> *Sent:* Tuesday, May 16, 2006 9:53 AM
> *To:* MAPSERVER-USERS at LISTS.UMN.EDU
> *Subject:* Re: [UMN_MAPSERVER-USERS] how to speed up MapServer
> performance?
>
> Zhonghai,
>
> You have the one big data set in there, which is the roads. If you're
> trying to display ALL the data in the one map, all at once, then 3
> secs isn't all that bad, considering you have 60 megs of data to work
> through.
>
> You may want to consider generalizing the data for viewing at
> different scales.
>
> The fileformat itself will create a tiny bit of an impact, since it
> all goes through OGR, for "raw" speed, use shapefiles , indexed with
> .qix ...
>
> The MapServer CGI is about the fastest mapping engine you'll find out
> there, open source or commercial!
>
> Also, what's the hardware like? Notably disk IO?
>
> Also, I'm sorry, but I must ask :) Does it have to be windows? On
> Windows, processes are quite expensive, which includes CGI ... this
> isn't the case on Linux, where processes are cheap, and threads are
> expensive. Also, Linux tends to cache things better in my experience.
>
> If you're using WMS, I think there's a FastCGI interface you could try
> using, though I'm not sure how mature it is.
>
> J.F.
> ------------------------------------------------------------------------
> *From:* UMN MapServer Users List
> [mailto:MAPSERVER-USERS at lists.umn.edu] *On Behalf Of *Zhonghai Wang
> *Sent:* May 16, 2006 4:09 AM
> *To:* MAPSERVER-USERS at lists.umn.edu
> *Subject:* Re: [UMN_MAPSERVER-USERS] how to speed up MapServer
> performance?
>
> Hi my friends,
>
> I am really very thankful for all your information, I am a newbie in
> MapServer.
>
> here is the data amount that I am using for the application:
> (all the source data is MapInfo format, and what I calculated is the
> ".MAP" file)
>
> 1. boundaries -- 388 KB
> 2. forests -- 9163 KB
> 3. lakes -- 26 KB
> 4. city parks -- 25 KB
> 5. settlement -- 2279 KB
> 6. rivers -- 1653 KB
> 7. road networks -- 56370 KB
> 8. railway -- 1343 KB
> 9. train station -- 27 KB
> 10 bus station -- 2 KB
> 11. tourist centers -- 9 KB
> 12. theaters -- 6 KB
> 13. shopping center -- 7 KB
> 14. city location -- 9 KB
>
> *****
> and here is how I am symbolizing the layers, mapfile for all these layers:
>
> ***
> LAYER
> NAME "Country"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_COUNTRY.TAB"
> TRANSPARENCY 40
> DEBUG ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> #NAME "Boundaries"
> STYLE
> SYMBOL 0
> COLOR 155 155 155
> OUTLINECOLOR 155 155 155
> BACKGROUNDCOLOR 255 255 255
> END
> END
> END
> LAYER
> NAME "lakes"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_LAKE.TAB"
> DEBUG ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Lake"
> STYLE
> COLOR 102 153 255
> END
> END
> END
> LAYER
> NAME "woodland"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_WOODLAND_G.TAB"
> DEBUG ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "woodland"
> STYLE
> COLOR 0 185 92
> END
> END
> END
> LAYER
> NAME "woodland"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_WOODLAND.TAB"
> MAXSCALE 100000
> #LABELITEM "Street_Label"
> #SYMBOLSCALE 50000
> #LABELMAXSCALE 80000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "woodland"
> STYLE
> COLOR 0 185 92
> END
> END
> END
> LAYER
> NAME "city parks"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_CITY_PARK.TAB"
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Park"
> STYLE
> SYMBOL 0
> COLOR 233 254 205
> END
> END
> END
> LAYER
> NAME "settlement"
> STATUS DEFAULT
> TYPE POLYGON
> #CLASSITEM "Area"
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_BUILT_UP_AREA.TAB"
> MAXSCALE 800000
> #LABELITEM "Street_Label"
> #SYMBOLSCALE 80000
> #LABELMAXSCALE 120000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "settlement"
> #EXPRESSION ([Area]>20000)
> STYLE
> COLOR 207 207 158
> END
> END
> END
> LAYER
> NAME "rivers"
> STATUS DEFAULT
> TYPE POLYGON
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_WATERWYS.TAB"
> MAXSCALE 800000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "river"
> STYLE
> COLOR 102 153 255
> END
> END
> END
> LAYER
> NAME "street50"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_S50.TAB"
> MAXSCALE 40000
> LABELITEM "Street_Label"
> SYMBOLSCALE 5000
> LABELMAXSCALE 20000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Street 50"
> LABEL
> # must be in your FONTSET
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 2
> MAXSIZE 8
> ANGLE AUTO
> POSITION CC
> OFFSET 0 0
> COLOR 0 0 255
> MINFEATURESIZE AUTO
> BUFFER 0
> END
> STYLE
> SYMBOL "point"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> COLOR 255 255 255
> END
> END
> END
> LAYER
> NAME "oneway"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_ONEWAY.TAB"
> MAXSCALE 40000
> SYMBOLSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Oneway"
> STYLE
> SYMBOL "oneway"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> COLOR 255 51 0
> END
> END
> END
> LAYER
> NAME "street40"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_S40.TAB"
> MAXSCALE 100000
> LABELITEM "Street_Label"
> SYMBOLSCALE 15000
> LABELMAXSCALE 30000
> LABELCACHE ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Street 40"
> LABEL
> # must be in the FONTSET
> TYPE TRUETYPE
> FONT "vera"
> SIZE 9
> MINSIZE 2
> MAXSIZE 9
> ANGLE AUTO
> POSITION CC
> OFFSET 0 0
> COLOR 0 0 255
> MINFEATURESIZE 20
> BUFFER 0
> END
> STYLE
> SYMBOL "point"
> SIZE 10
> MINSIZE 3
> MAXSIZE 10
> COLOR 160 160 160
> ANTIALIAS TRUE
> END
> STYLE
> SYMBOL "point"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> COLOR 255 255 255
> ANTIALIAS TRUE
> END
> END
> END
> LAYER
> NAME "street30"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_S30.TAB"
> MAXSCALE 250000
> LABELITEM "Street_Label"
> SYMBOLSCALE 40000
> LABELMAXSCALE 120000
> LABELCACHE ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Street 30"
> LABEL
> # must be in your FONTSET
> TYPE TRUETYPE
> FONT "vera"
> SIZE 9
> MINSIZE 2
> MAXSIZE 9
> ANGLE AUTO
> POSITION CC
> OFFSET 0 0
> COLOR 0 0 255
> MINFEATURESIZE 30
> #MINDISTANCE 10
> BUFFER 0
> END
> STYLE
> SYMBOL "point"
> SIZE 10
> MINSIZE 3
> MAXSIZE 10
> COLOR 160 160 160
> END
> STYLE
> SYMBOL "point"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> COLOR 255 204 51
> END
> END
> END
> LAYER
> NAME "railway"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_RAILRDS.TAB"
> MAXSCALE 8000
> SYMBOLSCALE 4000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "railway"
> SYMBOL 'point'
> COLOR 0 0 0
> SIZE 5
> MINSIZE 1
> MAXSIZE 5
> OVERLAYSYMBOL "dashedline"
> OVERLAYCOLOR 255 255 255
> OVERLAYSIZE 3
> OVERLAYMINSIZE 0
> OVERLAYMAXSIZE 3
> END
> END
> LAYER
> NAME "street20"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_S20.TAB"
> MAXSCALE 900000
> LABELITEM "Street_Label"
> SYMBOLSCALE 100000
> LABELMAXSCALE 430000
> LABELCACHE ON
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Street 20"
> LABEL
> # must be in your FONTSET
> TYPE TRUETYPE
> FONT "vera"
> SIZE 9
> MINSIZE 1
> MAXSIZE 9
> ANGLE AUTO
> POSITION CC
> OFFSET 0 0
> COLOR 0 0 255
> MINFEATURESIZE 50
> #MINDISTANCE 10
> BUFFER 0
> END
> STYLE
> SYMBOL "point"
> SIZE 10
> MINSIZE 3
> MAXSIZE 10
> COLOR 160 160 160
> END
> STYLE
> SYMBOL "point"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> COLOR 247 193 157
> END
> END
> END
> LAYER
> NAME "street10"
> STATUS DEFAULT
> TYPE LINE
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_S10_O.TAB"
> MAXSCALE 1700000
> LABELITEM "Street_Label"
> SYMBOLSCALE 400000
> LABELMAXSCALE 500000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Street 10"
> LABEL
> # must be in your FONTSET
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 1
> MAXSIZE 8
> ANGLE AUTO
> POSITION CC
> OFFSET 0 0
> COLOR 255 0 0
> BACKGROUNDCOLOR 153 204 153
> MINFEATURESIZE AUTO
> MINDISTANCE 200
> BUFFER 1
> END
> STYLE
> SYMBOL "point"
> SIZE 10
> MINSIZE 3
> MAXSIZE 10
> COLOR 255 0 0
> END
> STYLE
> SYMBOL "point"
> SIZE 6
> MINSIZE 1
> MAXSIZE 6
> COLOR 255 255 0
> END
> END
> END
> LAYER
> NAME "train station"
> STATUS OFF
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_TRAIN_STATION.TAB"
> MAXSCALE 10000
> #LABELITEM "Label"
> SYMBOLSCALE 1000
> LABELMAXSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Train station"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 2
> MAXSIZE 8
> ANGLE AUTO
> POSITION UC
> OFFSET 0 0
> END
> STYLE
> SYMBOL "triangle"
> COLOR 153 0 0
> SIZE 8
> MINSIZE 3
> MAXSIZE 8
> END
> END
> END
> LAYER
> NAME "bus station"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_BUS_STATION.TAB"
> MAXSCALE 10000
> LABELITEM "Label"
> SYMBOLSCALE 1000
> LABELMAXSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "bus station"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 2
> MAXSIZE 8
> ANGLE AUTO
> POSITION UC
> OFFSET 0 0
> END
> STYLE
> SYMBOL "triangle"
> COLOR 0 153 0
> SIZE 8
> MINSIZE 3
> MAXSIZE 8
> END
> END
> END
> LAYER
> NAME "LOCATIONS0"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_AND_LOCATIONS0.TAB"
> MAXSCALE 1000000
> LABELITEM "Name"
> SYMBOLSCALE 200000
> LABELMAXSCALE 500000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "LOCATIONS0"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 12
> MINSIZE 2
> MAXSIZE 12
> ANGLE AUTO
> POSITION AUTO
> OFFSET 0 0
> COLOR 0 0 255
> END
> STYLE
> SYMBOL "star"
> COLOR 255 0 0
> SIZE 18
> MINSIZE 8
> MAXSIZE 18
> END
> END
> END
> LAYER
> NAME "LOCATIONS1"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_AND_LOCATIONS1.TAB"
> MAXSCALE 800000
> LABELITEM "Name"
> SYMBOLSCALE 200000
> LABELMAXSCALE 500000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "LOCATIONS1"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 12
> MINSIZE 2
> MAXSIZE 12
> ANGLE AUTO
> POSITION AUTO
> OFFSET 0 0
> COLOR 0 0 255
> END
> STYLE
> SYMBOL "point"
> COLOR 153 153 0
> SIZE 8
> MINSIZE 3
> MAXSIZE 8
> END
> END
> END
> LAYER
> NAME "LOCATIONS2"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_AND_LOCATIONS2.TAB"
> MAXSCALE 800000
> LABELITEM "Name"
> SYMBOLSCALE 200000
> LABELMAXSCALE 500000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "LOCATIONS2"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 10
> MINSIZE 2
> MAXSIZE 10
> ANGLE AUTO
> POSITION AUTO
> OFFSET 0 0
> COLOR 0 0 255
> END
> STYLE
> SYMBOL "point"
> COLOR 153 153 0
> SIZE 6
> MINSIZE 1
> MAXSIZE 6
> END
> END
> END
> LAYER
> NAME "LOCATIONS3"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_AND_LOCATIONS3.TAB"
> MAXSCALE 400000
> LABELITEM "Name"
> SYMBOLSCALE 200000
> LABELMAXSCALE 200000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "LOCATIONS3"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 10
> MINSIZE 2
> MAXSIZE 10
> ANGLE AUTO
> POSITION AUTO
> OFFSET 0 0
> COLOR 0 0 255
> END
> STYLE
> SYMBOL "point"
> COLOR 153 51 153
> SIZE 6
> MINSIZE 1
> MAXSIZE 6
> END
> END
> END
> LAYER
> NAME "Tourist Information"
> STATUS OFF
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_TOURIST_INFORMATION.TAB"
> MAXSCALE 10000
> LABELITEM "Label"
> SYMBOLSCALE 1000
> LABELMAXSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Tourist Information"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 2
> MAXSIZE 8
> ANGLE AUTO
> POSITION UC
> OFFSET 0 0
> END
> STYLE
> SYMBOL "rectangle"
> COLOR 255 51 0
> SIZE 8
> MINSIZE 3
> MAXSIZE 8
> END
> END
> END
> LAYER
> NAME "Shopping Center"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_SHOPPING_CENTER.TAB"
> MAXSCALE 10000
> LABELITEM "Label"
> SYMBOLSCALE 1000
> LABELMAXSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "shopping center"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 10
> MINSIZE 2
> MAXSIZE 10
> ANGLE AUTO
> POSITION UC
> OFFSET 0 0
> END
> STYLE
> SYMBOL "special"
> COLOR 255 51 0
> SIZE 15
> MINSIZE 6
> MAXSIZE 15
> END
> END
> END
> LAYER
> NAME "Theater"
> STATUS DEFAULT
> TYPE POINT
> CONNECTIONTYPE OGR
> CONNECTION "CA_NAV_THEATER.TAB"
> MAXSCALE 10000
> LABELITEM "Label"
> SYMBOLSCALE 1000
> LABELMAXSCALE 5000
> PROJECTION
> "init=epsg:4326"
> END
> CLASS
> NAME "Theater"
> LABEL
> TYPE TRUETYPE
> FONT "vera"
> SIZE 8
> MINSIZE 2
> MAXSIZE 8
> ANGLE AUTO
> POSITION UC
> OFFSET 0 0
> END
> STYLE
> SYMBOL "triangle"
> COLOR 255 51 0
> SIZE 8
> MINSIZE 3
> MAXSIZE 8
> END
> END
> END
> ***********************
>
> is it still possible to speed up my application?
>
> ****
>
> the system parameters of my application:
>
> Windows XP professional
> MS4W 4.8.1
> data source -- MapInfo data
>
> *--only CGI parameters are used,since it is a pure static version with
> HTML,
>
> is it possible to develop a pure static application based on
> MapServer, even in conjunction with PHP/MapScript or Chameleon?
>
>
> thanks for any clues.
>
> zhonghai
>
> 16.05.2006
>
>
> On 5/15/06, *Steve Lime* <Steve.Lime at dnr.state.mn.us
> <mailto:Steve.Lime at dnr.state.mn.us>> wrote:
>
> We really need more information about the nature of the data. I
> mean if you've got
> 20 layers each with a million polygons and are trying to show all
> of them then 3 seconds
> might be really fast! Also, the way you are symbolizing features
> may impact things.
>
> In my experience neither 1 or 2 is worth considering...
>
> Steve
>
> Steve
>
> >>> Zhonghai Wang < zhonghaiw at GMAIL.COM
> <mailto:zhonghaiw at GMAIL.COM>> 5/15/2006 9:15:49 AM >>>
> Hi there,
>
> for a special purpose I've developed an static version application
> based on
> MapServer CGI, which means I just use pure HTML tages for the GUI,
> even
> without JavaScript code snippets to validate forms.
>
> I have about 20 map layers to display according to different map scale
> (ussing the MAXSCALE, SYMBOLSCALE AND LABELMAXSCALE), there are no
> data
> classifications within a layer object, the status of all layers
> are set as
> default.
>
> I've made a test on a standalone MapServer (XP system), every
> request takes
> about 3 second. Obvioursly it's not fast enough for a web
> application, since
> there may be many users requesting the server at the same time if the
> application is published on the web.
>
> Is MapServer really so slow? can anybody give me some ideas?should
> I modify
> the mapfiles?
>
> I am wondering whether the following solutions will work:
> 1. define every layer as a seperate mapfile, and combine them
> together by
> request
> 2. turn off the non-displayed layers off on the fly
>
> are these possible to speed up MapServer performance?
>
>
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