= Installation of a Sahana Eden Cluster =
[[TOC]]

NB This is NOT a supported architecture currently. We have no knowledge of anyone succesfully deploying like this, although it should be theoretically possible

Scalable 3-tier architecture:
* Database server (which could be Amazon RDS, and maybe a warm standby)
* Middleware servers (Web2Py & hence Eden)
* Web servers (e.g. Apache or Cherokee)

== Middleware ==
Some folders will need to be on a shared filesystem (e.g. NFS):
* {{{/uploads}}} (or they could be synced across e.g. using rsync)
* {{{/errors}}} {if these are to be viewed using Web UI)
* {{{/static/img/markers}}} (unless markers don't need to be customised via Web UI)
* {{{/sessions}}} (A better option is to use memcache for this - see {{{000_settings.py}}})
* {{{/databases}}} (if using dynamic tables, such as gis_layer_shapefile, otherwise these can simply be synced together, e.g. using rsync. Or we can now store these in the DB using dal.py's DatabaseStoredFile)

== See Also ==
* http://web2py.com/books/default/chapter/29/13#HAProxy-a-high-availability-load-balancer
* http://projects.unbit.it/uwsgi/