MapServer performance

Ed McNierney ed at TOPOZONE.COM
Fri Mar 23 12:33:49 EDT 2007


Antti -

Well, then that would be a good thing to learn about if you want to
understand your system performance.  "RAID stack" is a pretty generic
description, covering several different disk storage strategies, and
covering both IDE and SCSI drives with various interface channels.  Reading
from a parallel IDE 5,400 RPM RAID 1 system can be several times slower than
reading from a SAS 15K RPM RAID 5 array!

If you're going to optimize performance, find out more about your disk
subsystem.  Your hard disks are the slowest things in your computer.  If you
want to speed things up, it makes sense to see whether the slowest hardware
in your system is a bottleneck before you start looking elsewhere.

     - Ed

-- 
Ed McNierney
President and Chief Mapmaker
Maps a la carte, Inc. / TopoZone.com
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: (978) 251-4242
Fax: (978) 251-1396
ed at topozone.com

> From: antti siukola <siukola.antti at gmail.com>
> Date: Fri, 23 Mar 2007 18:14:04 +0200
> To: Ed McNierney <ed at topozone.com>
> Cc: <MAPSERVER-USERS at lists.umn.edu>
> Subject: Re: [UMN_MAPSERVER-USERS] MapServer performance
> 
> Hi!
> 
> The tiff's are stored on a RAID stack on the same server and the
> filesystem is ext3. I don't have very detailed description to give
> since I'm not administrating the server or have ever even seen it :)
> 
> Antti S
> 
> On 3/23/07, Ed McNierney <ed at topozone.com> wrote:
>> Antti -
>> 
>> 1 GB of RAM is not a lot for dealing with large raster files.  Could you
>> describe your hard disk subsystem in detail?  What kind of hardware are you
>> using to store the TIFF images?
>> 
>>      - Ed
>> 
>> --
>> Ed McNierney
>> President and Chief Mapmaker
>> Maps a la carte, Inc. / TopoZone.com
>> 73 Princeton Street, Suite 305
>> North Chelmsford, MA  01863
>> Phone: (978) 251-4242
>> Fax: (978) 251-1396
>> ed at topozone.com
>> 
>>> From: antti siukola <siukola.antti at GMAIL.COM>
>>> Reply-To: antti siukola <siukola.antti at GMAIL.COM>
>>> Date: Fri, 23 Mar 2007 11:11:18 +0200
>>> To: <MAPSERVER-USERS at LISTS.UMN.EDU>
>>> Subject: Re: [UMN_MAPSERVER-USERS] MapServer performance
>>> 
>>> Hi!
>>> 
>>> Thanks for the reply!
>>> 
>>> My tiff's are from 15M to 10G tiff tiles (about 500M each tile) and
>>> depending on the map theres the one 15M tiff or from 2 to 3 of the
>>> 500M tiles displayed (I have couple of map apps running on the
>>> server). It doesn't seem to matter how big the tiff's are since the
>>> performance is the quite the same. I also have the .shx files for my
>>> shape's.
>>> 
>>> The server doesn't get very much hit's since it's not an open for
>>> public application. I believe the average usage is about 1-10 users at
>>> the same time.
>>> 
>>> Hope this helps!
>>> 
>>> Antti S
>>> 
>>> On 3/21/07, Romolo Manfredini <romoloman at hotmail.com> wrote:
>>>> From: "antti siukola" :
>>>> 
>>>>> Oh, yes. I'm on linux with mapserver 4.8.4 and php mapscript. The
>>>>> server is quite new and powerful with dual xeon and 1024M of memory.
>>>>> Data sources are mostly SHP-files and few TABs for vector data and
>>>>> labels. The actual maps are .tif images. I'm using tiled tiff's and
>>>>> low-res images on upper scales.
>>>>> 
>>>> 
>>>> SHP and tiff files are typically bad beast to manage expecially if they are
>>>> big shape and big tiff, also dependig on file system type you may have some
>>>> performance issues related to locking and caching. (1 GB ram with large
>>>> files is not so much)
>>>> Also, do you have spatial index on your files (.shx) ?
>>>> Spatial index improve performances a lot.
>>>> May you tell me the size of your files and how many of them are involved in
>>>> a single map ?
>>>> 
>>>> Best Regards,
>>>> Romolo
>>>> 
>>>> 
>> 
>> 



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