Comparison of Distributed Operating Systems. Systems Discussed ◦Plan 9 ◦AgentOS ◦Clouds ◦E1...
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Transcript of Comparison of Distributed Operating Systems. Systems Discussed ◦Plan 9 ◦AgentOS ◦Clouds ◦E1...
Plan9 - 1Plan9 - 1History
◦Bell Labs 1984 – 2002 (and on)◦“Plan 9 from Bell Labs” based on
“Plan 9 from Outer Space.”
◦Replaced Unix as primary research platform. ◦Based on 9P protocol.
Accesses all resources, local and remote.
Plan9 - 2Plan9 - 2Notable architecture:
◦All system interfaces through file system. (pre-Linux)
Workstation - independent working environment
“Workstation” – aggregated resources, remote and local.
Plan9 - 3Plan9 - 3/proc
◦All processes are visible as files/net
◦All network traffic read/written through file system
Can import posix apps, emulate Berkeley socket interface through APE (ANSI/POSIX Environment)
AgentOS - 1AgentOS - 1
Originally designed by Harry Chen at UC, Irvine (1998)
Subsumed by The Bio-Networking Architecture project◦Grants from NSF, DARPA, and AFOSR (Air Force
Office of Scientific Research)
AgentOS - 2AgentOS - 2Goal: Ubiquitous Access
◦Nomadic and mobile usersBased on Java VM Agent based vs. RPC
◦Adaptive vs. dummy communicationByte code inefficiency
◦Just In Time Compilers with caching
Clouds - 1Clouds - 1History
◦Clouds is actually 2 separate operating systemsClouds V1, based on VAX kernel 1986Clouds V2, based on Ra kernel ~1989
Purpose◦Support distributed research at Georgia Institute of Technology
Clouds - 2Clouds - 2
Clouds based on the object/thread paradigm
At OS level there is only one type of object, clouds
Ra kernel implements persistent virtual memory◦Threads travel through objects◦Entry points
E1E1E1 first distributed commercially in 2005.Very much like clouds
◦Object/thread paradigm ◦Difference: Threads outside of objects
Objects replicated and synchronized◦Redundancy vs. loss of efficiency in replication
MOSIX - 1MOSIX - 1Version 0 (1977) – research project on
process migration◦based on Unix 6◦tested on PDP 11/45 and diskless 11/10
connected by parallel I/O◦Named: UNIX with satellite processors.
Current Version, 10 (2006) [MOSIX2]◦Supporting Linux Kernel 2.6
Generic Solution – dynamic management of resources.
MOSIX - 2MOSIX - 2
Core – ◦adaptive sharing algorithms◦Preemptive process migration◦Load balancing
Process placement System structure
Compatibility:◦Connect with any Linux, only one MOSIX hub required
MOSIX - 3MOSIX - 3Cluster – collection of computersGrid – collection of clustersPartition
◦Limited to 256 nodes (by IP addressing)Highly secureInfinitely scalable