[FreeNX-kNX] FreeNX and LVS (Linux virtual Server - cluster)

[Daniel Schwager]

Hi Fabian,

sorry for the intransparent email. So again:

- Requirements
        - 70 User should work with KDE
        - ThinClients should be use
        - nx-technologie should be use
        - the clients should suspend/resume nx-session (permantent session)
        - It should be able to play KDE-sound on the thinclient
        - It should be able to transfer files between thinclient (laptop)
and
          die KDE-Session (Samba ?)
        - the system should not have a SPOF (single point of failture)

** Parts of the concept:

Please have a look to http://www.dtnet.de/48747632/nx-kde-cluster.jpg
(picture)

- 3 Applicationservers for the 70 users
        - acting as a NFSv4-client for importing data home/data from
          an NFSv4 Fileserver
        - all 3 applicationservers are identical (cloned), that means they
          will have all the same programs installed

- Cluster
        - the user does not know, on with app-srv he works
        - we do not use openSSI nor beowulf for clustering
        - we want to use LVS (linuxvirtualserver.org) for clustering
                 - for the Clients, an LVS-Cluster has _one_ public IP
                  (the LVS routes internaly to the "best" app-srv)
                - establised TCP sessions (like ssh, nxproxy?, nxshell?,
nxtunnel?)
                  will always route to the same App-Srv
                - there's a feature for redundance/failover
                  (http://www.ultramonkey.org/3/topologies/)
                - Its scalable to x backendservers

- FreeNX
        - we want to use the following features
                - use thinclients (http://pxes.sf.net/) and nomachine
nxclient
                - sound should redirect to the thinclient
                - local ("thinclient", e.g. notbook) filesystem sould be
mounted
                  to the backend
                - persistent sessions (reconnect to a sessions after
suspending them)

- Architecture (concept / idea)
        - the nxserver has to be outside the cluster because of
          persistent sessions-handling
                - if the clients suspend the session, the nxserver has to
                  hold/keep the TCP session to the AppSrv (via LVS-Server).
It
                  the nxserver discontinue the session to the AppSrv, a
later
                  reconnect will be routed via LVS to another AppSrv ->
session
                  broken.
        - the nxserver creates a tunnsels betwwen nxserver and
applicationsever
                - the tunnel should be created via nxshell/nxtunnel
                - the tunnel have to use a TCP-session (this is because of
the
                  Loadbalancer LVS should redirect the tunnel always to the
same AppSrv ;-)
                - the tunnel should redirect display/multimedia
                - the tunnel should redirect samba (this ist not important,
because i can
                  mount the samba on the Nomachineserver in a NFS-Share.
This means, the
                  Applicationserver (nfs-client) has access to the "share")

Problems (no ideas ;-)
        - does the sound redirect will work, if we use nxshell/nxtunnel for
          connection from nxserver to  AppSrv ?
                - does the sound will be forward to the thinclient ? Or do
                  i have to instance a new artd at the nxserver ? or ...
        - could i replace the nxshell/nxtunnel in the architekture with
nxservers instances
          at the 3 app-servers ? If so, does the first nx-server handels the
permanent session ?
        - does the nxshell/nxtunnel use a TCP-session ?

Does somebody has other ideas for the concept ? Does my concept will work
for the
requirements ? (sound, permanent sessions, ...)

regards

Danny