distributedsystems-13 - Distributed Systems -1 A...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
-1 Distributed Systems 
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-2 A Distributed System
Background image of page 2
-3 Loosely Coupled Distributed Systems Users are aware of multiplicity of machines.  Access to  resources of various machines is done explicitly by: Remote logging into the appropriate remote machine. Transferring data from remote machines to local machines, via  the File Transfer Protocol (FTP) mechanism.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-4 Tightly Coupled Distributed-Systems Users not aware of multiplicity of machines.  Access to  remote resources similar to access to local resources Examples Data Migration – transfer data by transferring entire file, or  transferring only those portions of the file necessary for the  immediate task. Computation Migration – transfer the computation, rather  than the data, across the system.
Background image of page 4
-5 Distributed-Operating Systems (Cont.) Process Migration – execute an entire process, or parts of it, at  different sites. Load balancing – distribute processes across network to even the  workload. Computation speedup – subprocesses can run concurrently on different  sites. Hardware preference – process execution may require specialized  processor. Software preference – required software may be available at only a  particular site. Data access – run process remotely, rather than transfer all data locally.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-6 Why Distributed Systems? Communication Dealt with this when we talked about networks Resource sharing Computational speedup Reliability
Background image of page 6
-7 Resource Sharing Distributed Systems offer access to specialized resources  of many systems Example: Some nodes may have special databases Some nodes may have access to special hardware devices (e.g. tape  drives, printers, etc.) DS offers benefits of locating processing near data or  sharing special devices 
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
-8 OS Support for resource sharing Resource Management? Distributed OS can manage diverse resources of nodes in system Make resources visible on all nodes  Like VM, can provide functional illusion but rarely hide the  performance cost Scheduling? Distributed OS could schedule processes to run near the needed  resources If need to access data in a large database may be easier to ship  code there and results back than to request data be shipped to  code
Background image of page 8
-9 Design Issues   Transparency  – the distributed system should appear as a  conventional, centralized system to the user. Fault tolerance
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 55

distributedsystems-13 - Distributed Systems -1 A...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online