Newbie question (I think you can answer me)
Hello.
I am a newbie about EJB. But I am teacher of a Java course and I have
introduced EJB to my students. I have said them that EJB is good for big
applications but, when the application is small, is overkill (I read this in
several books). But then a student has asked me (I don't know how to
exppress the sentence in English) "How big has to be the application in
order to take advantage of EJB?". I mean: EJB is overkill for an application
with two concurrent users. But, if concurrent users are thousand, it is
necessary. Where is the limit between two situations? Of course, there is no
exact limit but it must exist some QUANTITATIVE parameter.
I had no reply for my student. Good question but no answer. I said that I
will look for this information.
I am getting mad looking for this information in Internet. I have seen no
studies that study such a basic question. Even it has been impossible to
find "a ballpark estimate". I seen EJB FAQs, pages, books about EJBs, but I
found nothing. Any information of this kind would help me a lot.
So, please, can anybody help me?
Any help would be greatly appreciated.
Thanks,
Pau Vic.
(I sent a former copy of this message to an unrelated thread. This was a
mistake. Please excuse the inconveniences)
Thank you, Ji.
Pau Vic.
"ji zhang" <[email protected]> escribió en el mensaje
news:[email protected]...
>
Hi Pau.
How big has to be the application in order to take advantage of EJB?There is no measurement standard for developers to decide the utilizationof EJB
in their applications. It is clearly unnecessary to develop a nonenterprise application
for only few ( as you mentioned 2 ) routing users with EJBs.
The question is more likely why using EJBs. Few major considerationslisted below:
>
1) A real production internet application is getting to rely on anapplication
container ( for example: #1 application server WebLogic ) to handleunderly resources,
backend works and Object life cycles.
By using EJBs, EJB container handles the sophisticate backend jobs foryou.
Developers may only focus on their business logics.
2) A real production internet application may be also a combination ofsome reusable
logical components. To reduce the application development hardness,modeled and
specification oriented plugable components such as EJBs may be used. Thatis also
why the EJB component vendors exist.
3) There are concepts of scalability and high availability in realproduction.
EJB components can be easily deployed to be scaled and load balanced inthe EJB
containers in a cluster. Fully implemented Weblogic Cluster is a goodexample.
>
There may be other advantages of using EJB as well.
Thanks.
Ji Zhang
Developer Relations Engineer
BEA WebLogic Support
"Pau Vic" <[email protected]> wrote:
Hello.
I am a newbie about EJB. But I am teacher of a Java course and I have
introduced EJB to my students. I have said them that EJB is good for
big
applications but, when the application is small, is overkill (I read
this in
several books). But then a student has asked me (I don't know how to
exppress the sentence in English) "How big has to be the application
in
order to take advantage of EJB?". I mean: EJB is overkill for an
application
with two concurrent users. But, if concurrent users are thousand, it
is
necessary. Where is the limit between two situations? Of course, there
is no
exact limit but it must exist some QUANTITATIVE parameter.
I had no reply for my student. Good question but no answer. I said that
I
will look for this information.
I am getting mad looking for this information in Internet. I have seen
no
studies that study such a basic question. Even it has been impossible
to
find "a ballpark estimate". I seen EJB FAQs, pages, books about EJBs,
but I
found nothing. Any information of this kind would help me a lot.
So, please, can anybody help me?
Any help would be greatly appreciated.
Thanks,
Pau Vic.
(I sent a former copy of this message to an unrelated thread. This was
a
mistake. Please excuse the inconveniences)
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