Ideal web server configuration

[Ed McNierney]

Mike -

You've gotten good advice so far, but if you're running PostgreSQL/PostGIS on the same machine, a lot depends on what "frequent" means in "frequent queries/updates".  As far as your GIS data goes, MapServer is basically a read-only application, and it's relatively easy to design a good disk subsystem (the slowest component in your server) for that application.  A good disk configuration for a highly interactive database with reads AND writes happening "frequently" is much more complicated, and harder (but more important) to get right.

Just as an example data point, I have long used 3Ware ATA RAID controllers with 8-disk RAID-5 arrays for raster data storage.  These provide an inexpensive solution with excellent read performance, and I essentially use those arrays as read-only volumes.  Write performance is much poorer on those volumes, and simultaneous read/write performance - as when I need to do a data update while a volume is in production - is TERRIBLE.  The writes are prioritized and they work OK but reading almost comes to a standstill.  None of this is surprising, and it's an appropriate design compromise.  But my PostgreSQL/PostGIS server does NOT use that same disk architecture <g>!

I never generalize, but I would not be surprised to find that the task of optimizing your hardware for your database application will do everything you need to optimize your hardware for your entire application suite.  Pay attention to that database first.

	- Ed

Ed McNierney
Chief Mapmaker
Demand Media / TopoZone.com
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On Behalf Of Mike Leahy
Sent: Monday, January 21, 2008 7:23 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Ideal web server configuration

Hello list,

I'm looking at ordering a new web server for the office I'm in, and I'm
wondering if anyone has any suggestions regarding the hardware that I
should choose.  Normally, I've worked with hardware that was already
available to me, so I've never really had to put consideration into this
upfront.  I know this may be a bit off-topic for this list, but I figure
people on this list will likely have some experience with this.

The application we're working on will involve multiple simultaneous
users interacting with a chameleon-based map interface.  The
communication between the client and server will generally involve AJAX
requests and downloading of updated map images generated by MapServer.
On the server side, we'll be running Apache, PHP (with MapScript), and a
PostgreSQL/PostGIS server that will be receiving frequent
queries/updates.  There will likely be some high resolution imagery, as
well as a variety of vector layers used in the map that is displayed.

Given that I have a relatively modest budget to work with, what I'd
really like to know is how I should prioritize the different hardware
specs that I can choose from (e.g., multiple CPUs/core, RAM, SATA/SAS
and/or RAID disk configurations, etc.).

Thanks in advance for any suggestions,
Mike