Short Description:
The XDFS was intended to provide a basis for database research. An XDFS transaction can cover updates to a number of files so that the atomicity of a higher level database operation can be maintained. In a database environment, a few highly interrelated a
nd often large files may be accessed concurrently by a number of clients. To reduce the degree of serialization, the XDFS provides fine-gained locking at the byte level. One of the main design goals of the XDFS was to allow a flexible allocation of comput
ing and storage resources to the file service. For each local network, the choice of the number of server processes and the amount of disk storage given to each server can be made by matching desired performance and cost. The glue which is used to assemb
le the different servers into a single file service is the atomic transaction mechanism which is designed to allow several servers to change files in a single atomic update.
Model: workstation, homogeneous
Properties: datagram, crash recovery, stable storage, synchronization,
atomic transactions, identity based
Transparency: location, access, concurrency, failure
Running on: Alto minicomputer
Date: 01.01.81 Ð ?
Xerox Corporation: "Xerox Network Systems Architecture". Stamford, Connecticut 1985 Xerox Corporation, Office Systems Division, XNSG 068504, April 1985.
Short Description:
ARGOS is a distributed message-based operating system for studying the ramifications of the Virtual Port Memory Architecture (VPM). In the VPM architecture individual processing elements reference a global memory using system-wide virtual addresses transl
ated at the memory. There is a separate message bus used for all interprocessor messages. The processing elements have large caches with no coherency support. ARGUS provides each process a private process space, performing message-based communication and
synchronization via messages. ARGOS uses the global memory to implement rapid message passing and copy-on-write between processes. The object manager, file manager, and pager all utilize the global memory for rapid communication and the message bus for th
e synchronization.
Model: Global Memory Message Passing Multiprocessor, shared memory
Properties: message passing, UNIX-compatible, real-time support
Transparency:
Running on: VMP machine consisting of MC 68020 processors
Date: 1989
FTP: ftp.cse.ucsc.edu /pub/tcos