[Mapserver-users] Hosting mapserver

Tue Jan 28 16:38:53 EST 2003

Just wanted to say your MapServer client is great.  And your maps look very
good (ugly maps are a pet peeve of mine, and they are all too common).  Well
done.

It really screams - as long as you don't turn on the rasters.  The raster
layer does tend to slow it down.  I would be surprised if it would has any
problem at all with 10 concurrent users.

I've put a ton of work into my Rosa based MapServer client.  But your app
really makes me want to switch to DHTML.  It runs much smoother, and
alleviates some of the headaches I'm experiencing with Rosa.

-Dan

-----Original Message-----
From: Steve Young [mailto:steve at sierraclubbc.org]
Sent: Tuesday, January 28, 2003 2:58 PM
To: Ed McNierney; Mapserver-users at lists.gis.umn.edu
Subject: RE: [Mapserver-users] Hosting mapserver

Thanks for the input Ed,

I was going to post the site to the list in a couple of weeks once it was
complete, but I'm happy to take a few hits now. Any and all advice is
appreciated. http://scbc.dyndns.org.

It is based on Steve Lime's DHTML landview site. Thanks to Paul Ramsey at
Refractions and Steve Lime for their help. All the bits that are ugly, don't
work, or cause a grimace are mine.

We represent two enviro non-profit groups so Mapserver has been the best and
virtually only route that we could use to develop and provide web-mapping
within our community. So thanks also to all the open source developers that
support Mapserver.

All the vector data is in shapefiles. Images are tiff and png. They're all
indexed and where size of frequently accessed files exceeded 5-50Mb I've
used tiles. There's more data than could be held in RAM (around 4Gig). I
think I have it reasonably optimised for speed, though I welcome any
suggestions to make it faster.

Re - max-minscale. It uses three principle datasets 1:2mil 1:250k and 1:50k
so there's a bit of stretching in places.

The box's only job is to host Mapserver. This is the only site it's hosting,
but depending on it's capacity more may be added.

Users are free to zoom and pan to any scale within the mapfile limit so
image caching isn't used.

I'm getting out of my depth measuring multi-user requests. Looking at the
processes while Mapserver requests are being run there doesn't appear to be
an appreciable hit on memory (I don't know how to measure the exact usage).
CPU usage looks to be around 5-10%. Does this mean that CPU is more of a
constraint than memory?

The site's target audience is small so my goal is to have a server that will
handle 10 concurrent users.

Steve

-----Original Message-----
From: Ed McNierney [mailto:ed at topozone.com]
Sent: Tuesday, January 28, 2003 11:26 AM
To: Steve Young; Mapserver-users at lists.gis.umn.edu
Subject: RE: [Mapserver-users] Hosting mapserver

Steve -

You're asking an extremely complicated question.  If you want the real
answer, you'll need to do some stress/load testing with examples of the
actual data set you're dealing with.

The organization and structure of your data sets have a MAJOR impact on
MapServer performance, so it's impossible to answer the question without
knowing a lot about the application.

Here are some things to think about.  I'm not trying to be difficult, but
your question is basically unanswerable without a lot more research and/or
testing.

You can break these into two categories - factors which affect the response
time for a single map request, and factors which affect the response time
for multiple simultaneous map requests.

Single Map Request
====== === =======

How large are your data sets?  If the data is such that it's mostly or
entirely cached in RAM, that's very good.  How many layers do you use?  Are
the vector layers indexed (shptree)?  If you're using raster layers, are
they sampled appropriately?  Will users zoom in and out on your data or will
they mostly be scrolling around at one zoom scale?  Have you carefully set
minscale and maxscale settings so you're not drawing too much data?

Simultaneous Requests
============ ========

What is MapServer's working set to create a single map (this will depend on
how it's built and on your data)?  The more memory a single MapServer
instance requires, the fewer simultaneous users you can support before you
start swapping.  Are you running on a single IDE drive?  If so, you're going
to get into trouble quickly, and if you start swapping you're doomed.  Is
this a dedicated machine running only MapServer and associated HTML pages?

Is this application on a system we can look at?  If so, you'll probably get
better input and comments.

	- Ed

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

-----Original Message-----
From: Steve Young [mailto:steve at sierraclubbc.org]
Sent: Tuesday, January 28, 2003 2:08 PM
To: Mapserver-users at lists.gis.umn.edu
Subject: [Mapserver-users] Hosting mapserver

Hi,

I'm planning to launch a new mapserver site in a couple of weeks. I have it
running on RH 7.2, Apache 1.3x Mapserver 3.6. The box is a Duron 950 with
256Mb RAM and 7200rpm ide drive. When it's just me on the site most images
pop up in less than a second. I'd like to give the client some idea how many
simultaneous users the site can comfortably support. Does anyone have a
similar set up running?

TIA,

Steve

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