Hi can any one explain the difference between three-tier and multi-tier ? also better if you can
Explain the advantages and disadvantages when each of them examined under the following topics: scalability, maintainability, reliability, availability, extensibility, performance, manageability, and security (flexibility)
A "tier" is nothing but the layer/system which performs some actions during the flow.
Three tier typically involves 3 layers or systems to handle the flow. A client to make a request, a middle layer to deal with the intermediate logic handling and make certain decisions based on the request etc, a database to store the data. This make sense in terms of an enterprise application. You may have a look at here http://en.wikipedia.org/wiki/Three_tier for a detailed explanation.
Multi-tier means you have many such levels/layers/systems in the scenario.
Originally posted by janaka chandrajith: .. Explain the advantages and disadvantages when each of them examined under the following topics: scalability, maintainability, reliability, availability, extensibility, performance, manageability, and security (flexibility)
This is more like an interview question Many of them are self describing entities. You yourself can get to know if you think a bit about them.
Scalability - the ability to have more systems involved - the growth of the system/features etc.,
Availability - it may be interrelated with Reliability - the ability of the application to be available and providing access by different means or ways. Say through a web browser, mobile phone etc.,
Reliability - the ability to which the system can be trusted in case of failures, unexpected errors etc., An ideal system should have the facility to intimate the user about the errors and handle those exceptions in a graceful manner
Performance - the ability of a system to respond to the user's queries as early as possible. As performance is an abstract concept, it may be applied on variety of things like memory, time etc.
Security(flexibility)? Security is all about deciding who can be allowed to access the system and who can not? I don't think what the term flexibility can do here in security as all it can do is either permit or deny the user's request.
Hi Janaka, I wrote a blog yesterday about a related topic "Two, Three, N-tier which one should I pick?" and it detailed the differences between each approach, please let me know if that helps you. http://javaxcross.blogspot.com/
Originally posted by Juan Pablo Crossley: Hi Janaka, I wrote a blog yesterday about a related topic "Two, Three, N-tier which one should I pick?" and it detailed the differences between each approach, please let me know if that helps you. http://javaxcross.blogspot.com/
The blog entry looks so nice. Thank you for the link.
Great work buddy!
Juan Pablo Crossley
Joined: Oct 16, 2007
thanks Raghavan, I will try to post an article every week about java topics (some of them will be related to java certifications), will be great if the community suggests some topics to write on (I really don't want to post articles with the common questions, there are a lot of sites with these). So, leave a comment in one of my articles and I will try to solve the questions (off course, everything depends on my knowledge and I will do my best to solve every question).