Interactive Session Support (ISS) is a part of IBM's LoadLeveler product that allows users to see multiple UNIX workstations as a single logical service. For example, the three systems machine1, machine2 and machine3 could be given a service name of ourcluster.iss---users telnetting (or using rsh, rlogin or ftp) to ourcluster.iss would be routed to whichever of the three systems has the lightest load.
We now provide an ISS service at CERN which provides service names for central UNIX clusters and also one private cluster. For some systems we have also created an alias that points to the ISS service name to make using this service even easier.
We strongly encourage users of these services to connect via the service name or alias rather than asking for an individual node. Using the service name means that you will be routed to the machine with the lightest load and also that you don't need to worry as nodes are added to (or removed from) the cluster.
Users outside CERN can also use the service name or alias but must, of course, add ``cern.ch''---so a user can connect to the ATLAS Work Group Server from outside CERN using the name atlas.wgs.cern.ch or atlas.cern.ch. This full name can also be used within CERN but the short form should be sufficient. (One exception for the moment is that people connecting from home via the ACB service must give the full name. This is due to a bug which we hope will be fixed in the near future.)
If you manage a workstation cluster and would like to take advantage of this ISS service please send an Email to firstname.lastname@example.org.