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Shamayel Afzal Khan (F-46066) – BBA 23 (B) – Semester 4, Spring 2012 - APCOMSClass Assignment- Fundamentals of Database-4th June 2012
2-Tier Client Server Architecture vs. 3-Tier Client Server Architecture
2-Tier Client Server Architecture vs. 3-Tier Client Server
Architecture
1. 2-Tier Client Server Architecture :
i. Definition :
It is a client server architecture based on 2-Tier, which implies that the Clients
and Server are on two different machines: such that the application layer is on
the client’s side and the database lies on the Server side. There are two layers
i.e. the client layers and the server or the database layer.
ii. Explanation:
In 2-Tier Client Server Architecture, client sends a request to the server through
the client machine, as a result a response is sent back to the client machine after
the server performs the required task.
However, there is a difference between the traditional and modern 2-Tier Client
Server Architecture. Previously, the client machine has the application layer
which use to slow down the client’s machine. Now, in the modern 2-Tier Client
Server Architecture, the server holds the application layers along with the
database layer for the reason that the server is a powerful processing machine
with large disk space. Therefore, it reduces the burden over the client’s
machine.
iii. Advantages :
a. It is easy to be established as compared to the 3-Tier Client Server
Architecture.
b. The Client has more access to the database and can easily use some special
tools as compared to the 3-Tier Client Server Architecture.
iv. Disadvantages :
a. It cannot process requests from clients beyond a certain limit at a time.
b. The processing speed is very slow.
c. It takes more time to process the requests.
d. It has a drawback of cost inefficiency as most of the users can only use the
connection 2-3 % of their time.
e. It lacks the portability feature.
v. Figure :
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Shamayel Afzal Khan (F-46066) – BBA 23 (B) – Semester 4, Spring 2012 - APCOMSClass Assignment- Fundamentals of Database-4th June 2012
2-Tier Client Server Architecture vs. 3-Tier Client Server Architecture
2. 3-Tier Client Server Architecture :
i. Definition :
It is a client server architecture based on 3-Tier, which implies that the Clients
and Server are on two different machines with an addition of a third
intermediate layer known is application layer or web layer: such that the
application layer or the web layer is in between the client and the server. There
are three layers i.e. the client layers and the server or the database layer and the
web layer or the application layer.
ii. Explanation:
In 3-Tier Client Server Architecture, the application layer neither is on the
server machine, nor is it on the client’s machine but instead, it is on a separate
machine. However, the server as a whole consists of both the application layer
and the database layer. In this regards, the client is at the front just request the
data and it is displayed to him on his machine.
With the introduction of an additional tier, the system is easy to manage as the
load of requests, processing is equally shared among the machines. Thus, as a
result, the server is either processing the data or using the application. No
additional resources are being consumed. The cycle goes on in a way that the
client request is sent to application server from where it is sent to the database
server, which processes the request and sends the data back to the application
server and finally the application server sends the data to the client.
iii. Advantages :
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Shamayel Afzal Khan (F-46066) – BBA 23 (B) – Semester 4, Spring 2012 - APCOMSClass Assignment- Fundamentals of Database-4th June 2012
2-Tier Client Server Architecture vs. 3-Tier Client Server Architecture
a. The modification as well as the replacement of any single tier can takes
place without affecting any other tier.
b. There is an efficient sharing of load through its distribution in form of three
layers.
c. The data integrity checks can be placed without affecting the clients. Only
the accurate data can be allowed to update.
d. The data access is more secure through introduction of security checks and
in this regards the client cannot directly access the database server.
e. The failure rate is comparatively low than the 2-Tier Client Server
Architecture.
f. The processing rate is quicker than the 2-Tier Client Server Architecture.
g. The performance is better, as the Business Logic is separate from the
database and is on a separate application layer. It has a benefit that from the
scalability aspect i.e. the application server can be based on more than one
machine.
h. It has a portability feature.
iv. Disadvantages :
a. It is more complex.
b. Some of its advantages are overlooked, when the user needs a direct access
to database in order to use special tools such as report generation.
v. Figure :
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Shamayel Afzal Khan (F-46066) – BBA 23 (B) – Semester 4, Spring 2012 - APCOMSClass Assignment- Fundamentals of Database-4th June 2012
2-Tier Client Server Architecture vs. 3-Tier Client Server Architecture
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