From what you have told me, it sounds like you either dont need a middle
layer, or your middle layer needs to be simplified.
It is never going to be faster with a middle layer, you may not easily be
able to prover it slower with impirical data but it nevertheless will be,
even if not in a material sense.
As for security, that depends on what you mean. Its not going to make the
data layer any more secure than its already designed to be, its not going to
make the application more secure either. One thing it will do ( depending on
how you design it ) is to make it tougher for developers to visibly cut
through the middle layer in terms of calls, but ultimately its not going to
prevent it either unless you start adding certificates to each layer, and
hey who wants to do that. ?
An old developer that I knew used to keep a four letter sign in 96point text
above his screen with the word KISS on it, ( Keep It Simple Stupid ). An
axiom he swore by, and he allways wrote concise readable robust code. Life
is too complex as it is without adding complexity where its not required.
What I am saying is, if you dont need it, and you will instinctively know
this, then dont do it.
HTH
"BJ" <> wrote in message
news: ups.com...
> On Sep 23, 1:38 am, "Just Me" <news.microsoft.com> wrote:
>> Well I don't think so really.
> Which question?
>
>> I personally think it depends how complex your middle layer is likely to
>> be.
>> For example, if you were dealing with a business which had hundreds or
>> protocols regarding how it did business then a business layer is
>> definitely
>> worth doing but if we are only talking about a few then why bother one
>> could
>> argue.
>
> I just started looking at the existing application, but it seems that
> the middle tire is making calls to the data layer and passing it off
> to the client. And yes I do agree that if you have dissimilar systems
> trying to access the same data or a massive audit process that
> interfaces with multiple systems (IBM 3270 Mainframe, Solaris, Win NT)
> then a middle tier does make sense.
>
>>
>> The purists will advocate multi tier and will even argue that the tiered
>> must be firewalled using web services to prevent such terrible erroneous
>> measures being carried out but errant developers. But that's a purist for
>> you. The advantage of taking such and approach is that you then have a
>> structured way to evolve your middle layer.
>
> I can't do things because it's the way a purists says it has to be
> done a certain way. We'd all have dumb terminals and writing programs
> in COBOL or Assembler.
>
>> For me, its horses for courses, if it looks like I need to handle a
>> complex
>> situation, then I'd better have a very formal method of doing so, if its
>> simple, why complicate it. And if it's simple, abut has been designed in
>> a
>> complex way, then is it easier to add to the existing complexity or
>> should I
>> simplify it, and in doing so where is the business case for it. ?
>
> I think what you are saying is the middle tier simplifies a complex
> design? Please correct me if I understood that wrong.
>
> The application is used in a very specific way, show me an image from
> my group of images. Currently, the client application makes a call to
> the service, which in turn utilizes the imaging API's to retrieve the
> image. There are some direct calls to the database by the middle
> tier. The middle tier calls are specific to that application. I
> truly do appreciate your response and I'm not arguing any fact other
> than by keeping the middle tier what do I gain? By losing the middle
> tier, what do I lose?
>
> I guess I was hoping for a smack up side my head to say, "hey its 35%
> faster to use a middle tier" or "its more secure" or "it's the only
> way to support 100, 200, 300, 400+ users". I'm pretty sure invoking a
> middle tier is not faster. Instead of going from point A to Z, the
> process is going from A to M to Z utilizing a protocol with a lot of
> overhead (SOAP). One of the developers told me SOAP was the new way
> to invoke services and CORBA and RMI was the old school way. Well, I
> can say with certainty that CORBA and RMI are older than SOAP, but
> unless the number have changed over the past 7 years the evidence says
> SOAP is the slowest of those technologies. I'll use it but don't tell
> me CORBA and RMI have gone the way of the dinos.
>
> As far as security, I don't know. Is having a middle tier more
> secure? If I make it a web form application or a client win form
> application, it will sit on the network behind the corporate
> firewall. Today security is maintained utilizing a security table and
> LDAP. They are slowly moving over to AD.
>
> As far as being able to support a large group of users, I don't know
> the answer to that one. I do know that there is only one BEA domain
> and one Database for this application. If some other application
> utilizes access to that Database by way of the middle tier, then leave
> it up for them. I did over hear the supervisor say they were looking
> for a more supportable solution. Today, if a change has to happen in
> the middle tier there is one developer for all three BEA domains that
> writes those services. It took us two full days to find a problem in
> the VB6 code because we could figure out a Tuxedo error 12.
>
> Again thank you for the reply, but so far for this application, I
> really don't see why I would need to maintain a middle tier.
>
>