Advantages and disadvantages of distributed system over centralized system?

Advantages of Distributed Systems over Centralized ones

1:Incremental growth:Computing power can be added in small

increments

2:Reliability:If one machine crashes, the system as a whole can

still survive

3:Speed:

A distributed system may have more total computing power than a

mainframe

4:Open system:

This is the most important point and themost characteristic point

of a distributed system.

Since it is an open system it is always ready to communicate with

other systems.

an open system that scales has an advantage over a perfectly closed

and self-contained system.

Economic:ANd Microprocessors offer a better price/performance than

mainframes

Disadvantages of Distributed Systems over Centralized ones

1:As i previously told you distributed systems will have an

inherent security issue.

2:Networking:If the network gets saturated then problems with

transmission will surface.

3:Software:There is currently very little less software support for

Distributed system.

4:Troubleshooting:Troubleshooting and diagnosing problems in a

distributed system can also become more difficult, because the

analysis may require connecting to remote nodes or inspecting

communication between nodes.

To design my own distribute system i would do the following:

1:Distributed users always pose a threat to be exposed by

hackers.Therefore I'l create groups of users and will provide them

constrained access to data.

2:Authentication required by all users who use the system.

3:encryption..that is for message protection,

4:The whole Domain is also to be protected via firewalls..so i

would install good Firewalls.

5:Would install good anti viruses on my machines which are a part of the distributed system, as these systems are prone to the domino effect that is if one system gets effected the whole network will be susceptible to becoming effected.

6:Design:

As far as possible I'll keep the design simple and as local as possible.Will probably use a virtual private network.

Will use machines that are compatible with each other.

Will enforce secure access on all users.

Will probably save the most important, the database on another well equipped machine so that it has a system that is only dedicated to look after the database.