The New Unix-based Services
A new Unix-based set of services is being constructed in the CN-DCI group to provide for the foreseen move away from mainframes towards Unix-based systems, particularly within the physics community. In order to provide meaningful support services in a heterogeneous Unix world with the limited manpower available it is considered essential to adopt some standards and a scalable architecture.
This has as a central focus an ``institutional file system'', currently AFS (Andrew File System), with the intention to move to DFS (Distributed File Services from OSF) as soon as this is generally available on CERN's major platforms. Binary application servers, exploiting the features of AFS (such as replication as necessary for performance), are being provided within a second phase of ASIS. Home directory file services based on AFS are being built up, as is an AFS-Mail service. Other tools are being provided or adapted in similar fashion to match the AFS-based environment.
At the same time DCI is building Unix-based Workgroup Servers (WGS) for certain specific physics groups and Public Login Unix Servers (PLUS) for general use, all based on this architecture. It is thus intended that these machines will be largely ``anonymous'', being equipped with only a standardised system disk and AFS client software with an AFS Cache. User files will be stored on the centrally supported home directory file service, and programs, applications, tools etc. will be supplied via AFS from ASIS and other AFS servers.
We will also make the tools used to configure Work Group Servers and Plus machines available to workstation owners. ``Shrink-wrapped Unix Environment'' (SUE) scripts will provide an easy way to customise workstations for the CERN environment and will also allow for optional automatic updates when necessary.
The aim is to provide an environment so that all users, whether sitting at an X terminal or workstation, can work effectively whatever the machine they are connected to. This interactive environment will also be integrated with CORE services so that jobs can be developed and tested interactively and then submitted unchanged to the batch service. We will be providing the HEP wide user profiles developed at DESY (and currently being adapted for CERN use) and are investigating services such as Zephyr--the Athena messaging service--that have been developed for other interactive Unix environments.
A. Cass, CN-DCI-UES
User Migration Task Force
Within the context of the migration of the user community away from VM/CMS, (currently more than 4000 users still use CERNVM each week), the CN Division has created a User Migration Task Force, UMTF, whose mandate is to provide a suitable selection of programs, tools and applications for CERN's user community within the new Unix environment that is being created. This work has some analogy with the creation of the ``P- disk'' for the CERNVM service. The UMTF will involve responsible people from other groups and divisions as appropriate, and will be chaired by M. Marquina.
M. Marquina, CN-DCI-ACT
ASIS in the AFS world
Included in the decision to use AFS (and later DFS) as a strategic part of the new Unix services, was the decision that ASIS should move from being a repository of software that people could copy onto private machines, to become the file server for the CERN Program Library and publicly-available applications.
The master copy of all the software is now stored under AFS and the ASIS01 machine contains a regularly-mirrored copy of the master AFS version. While anonymous ftp access to the software will be maintained, it is hoped that the number of users accessing it via NFS will steadily decrease as AFS becomes more generally used.
The move to AFS has allowed us to introduce support for multiple versions of applications and to profit from the replication features of AFS to introduce new versions of software in a more controlled way. The replication features will also allow us to have multiple copies of the applications available on multiple servers providing both hardware backup and scalability to handle an increasing load.
As a service to people maintaiting publicly-available software stored within ASIS, reference machines have been installed for generating the master copy in a CERN standard environment. The reference machines have been installed with the currently recommended version of the operating system, compilers and libraries and includes support for SunOS, Sun/Solaris, DEC/Ultrix, DEC/OSF, HP-UX, IBM/RS6000 and SGI/Irix.
The other important aspect of the ASIS service is the selection of software that is made available and the degree of support provided. It will be impossible to provide good support for all potentially interesting software and it will be one of the tasks of the User Migration Task Force to identify the 'recommended' products that will receive a higher level of support.
P. Defert, CN-DCI-GS
J. Richards, CN-DCI-GS