Mapserver in a cluster

[Stephen Woodbridge]

percy wrote:
> we are interested in this as well. we have a beowulf cluster, and would 
> like to explore load-balancing in anticipation of increased demand for 
> our geospatial data.
> 
> I wonder what Ed over at Topozone does :-)
> 
> Salvatore Cozzolongo wrote:
>> I would put mapserver cgi in a cluster (HA or HPC). The web server 
>> should get up the cgi in this environment. According to you, is it 
>> possible? what type of cluster
>> do you try to use? Best Regards to all
>> -- 
>> Salvatore Cozzolongo
>>
> 
I can speak to how this was originally set up. I believe Ed has made 
some changes. There are approximately 10 servers with the USGS DOQQ data 
organized into one degree blocks and spread across the servers in a 
somewhat random order. When a map request comes it it is directed to the 
system that owns the one degree block at the center of the map. All 
systems are cross mounted using a Samba file system because of its 
ability to recover from connection failures, which NFS can not do, so 
every system looks like it has the full compliment of DOQQS.

I'll let Ed jump in to say more if he wants.

At Where2getit, we have a cluster with 8-9 servers behind a linux load 
balancer. The load balancer monitors the client systems and their load 
and dispatches requests to them respectively. These systems are all 
severing vector data, and each is full compliment of data and software. 
In fact each is a mirror of the master for that cluster. We can pull any 
server from the load for maintenance and the remainder will handle the 
load. If a server has a hardware failure the load balancer will remove 
it from the load and sysadmins are paged. If we need more capacity, we 
can load the basic OS on a box, mirror it from the master and add it to 
the load.

-Steve