Some time ago I asked about hardware considerations of cloud based GeoStack implementation. As a follow up to this question
There are some good pointers in related question already, but they mainly refer to PostGIS.
So I wanted to ask you for some advice regarding memory allocation for a simple Web mapping Ubuntu box, based on PostGIS, GeoServer and OpenLayers/GeoEXT.
By simple in this case I mean serving maximum 10-20 WMS layers, caching, getFeatureInfo, and getting legends. Underlying dataset will consists of ~3000 polygons of administrative areas. It will be hosted on cloud VPS - either AWS or rackspace.
I have three questions regarding this setup:
Does it make sense to keep PostgreSQL and Geoserver on two separate instances? Or is it better to focus on one, more powerful server?
Cloud servers are scalable. So assuming 100% is the total amount of memory available - what would be your suggestions of setting memory parameters in PostgreSQL? And how about java memory allocation for GeoServer?
Any other hints for tweaking memory?
Thanks for help.
PS I asked this question on GeoServer Users mailing lists but haven't recieved any suggestions so far.