1 distributed-systems-template-modified
TRANSCRIPT
Execution
Environments for
Distributed
Computing
Distributed Systems
EEDC
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Master in Computer Architecture,
Networks and Systems - CANS
Homework number: 1
Group number: 51, 52, 53
Group members: Hui Shang – [email protected]
Malik Adnan – [email protected]
Zafar Gilani – [email protected]
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Outline
What are Distributed Systems (DS)?
Why do we need Distributed Systems?
Different types and applications
Advantages and Disadvantages
An example of DS - Space Shuttle
Challenges and Future perspective
Questions?
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What are Distributed Systems?
Many inter-communicating autonomous entities
scattered over a region.
- Solar system, earth-moon system,ecosystem…
A collection of independent computers that appear to
the users of the system as a single coherent system
- world wide web, network of stations…
“ you know you have a distributed system when the
crash of a computer you have never heard of stops
you from getting any work done.” – Leslie Lamport
The World is distributed!
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Why do we need Distributed Systems?
Collaboration among specialized entities works more efficiently.
ex: How five senses of your brain work?
Deciding what to eat: – aroma (how it smells)
– texture (how it looks)
– …
Availability of powerful yet cheap microprocessors and continuing advances in communication technology.
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DS in the nature
Solar system: relevance to inner planets and their
motion.
Earth-moon system: relevance to how water currents
move over the surface of the earth.
Ecosystem: Insects and amphibians,Trees and
crops, Vegetables and fruits…
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Some examples of DS applications
The world wide web
Network of branch office computers- information
system to handle automatic processing of orders.
- Banking systems, ebay …
Telephone and cellular networks
Sensor networks.
Aircraft systems.
manufacturing systems
- automated assembly line
.. and more!
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Organization of DS
A distributed system organized as middleware. The
middleware layer extends over multiputle machines.
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Advantages and Disadvantages
Advantages - Economics
cost effective way to increase computing power
- Speed
more computing power than mainframe
- Reliability (fault tolerance)
If one machine crashes, the system as a whole can survive
- Inherent distribution
many applications involve, by their nature, spatially separated machines
- Incremental growth
Computing power grow by adding new machines
- Sharing of resources
banking, reservation systems, printers…
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Advantages and Disadvantages
Disadvantages
- Software
What kind of operating system, programming language and
applications ?
- Network
Problems are created by network infrastructure, loss of messages,
overloading…
- Security
Sharing generate the problem of data security
- More points of failure
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Example:DS in space shuttle
Why DS?
Major components: – Orbiters,
– Recoverable boosters,
– External tanks,
– Payloads,
– Supporting infrastructure
These components are controlled by multiple custom made supercomputers during the launch and re-entry procedures. Too complex for the humans to control!!
DS can balance the workload.
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How DS makes it work?
Each shuttle had five supercomputers.
Each was fed by measurements from thousands of
sensors installed all over the shuttle.
The computers then voted for the most optimal
solution.
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Challenges of Distributed System
Secure communication over public networks
- anyone else see or change the message?
Build fault-tolerant system
- building reliable system for unreliable components
- nodes fail independently
Replication, caching ,naming
- placing data and computation for effective resource
sharing
Coordination and shared state
- how to make agreement?
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The future
Internet is going
to get bigger and
bigger!
Inter-planetary
internet before
the advent of
humans on other
planets?
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DS application in the future
More applications on the following:
Cloud computing.
Online distributed file repository:
– Hadoop
Wireless energy transfer
And more…
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The future ..
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