services vs compounents

[trouling]

Just finishing an intro book to VB programming; I covered basics on how
to due this or that for services and components. However, I'm still
wondering the following. What's the main advantage or reason to use:
web service, system service, or component? What advantages does one
have over the other? They all seem to expose methods that can be used
one way or another.

 

[stand__sure]

they are all twists on the same idea: reusable "components"

web services are generally used when cross-platform access is needed --
the format is generally XML/SOAP and as such is ideal for heterogeneous
interoperability (examples would be a weather service, a stock quote
service, etc.)

remoting services tend to be used for windows/.net to windows/.net
functionality -- they offer some security features not normally found
in webservices and also allow some client-side control of the lifetime
of the server object... also, they can be exposed by IIS, and at times
can use non-default constructors

a windows service generally is not accessible from anywhere but the
machine on which it runs. they are useful for scenarios lie offline
data processing (e.g. I frequently use a FileSystemWatcher that updates
a database when a datafile is saved in a particular directory)

a serviced component (COM+) offers a different security model and is
accessible from non .NET code. it offers certain features like message
queueing, transactional processing, etc.

normally a specific design need will eliminate certain possibilities.
the 70-310 course books from both Microsoft and Que provide a good
starting point.

 

[trouling]

they are all twists on the same idea: reusable "components"

web services are generally used when cross-platform access is needed --
the format is generally XML/SOAP and as such is ideal for heterogeneous
interoperability (examples would be a weather service, a stock quote
service, etc.)

remoting services tend to be used for windows/.net to windows/.net
functionality -- they offer some security features not normally found
in webservices and also allow some client-side control of the lifetime
of the server object... also, they can be exposed by IIS, and at times
can use non-default constructors

a windows service generally is not accessible from anywhere but the
machine on which it runs. they are useful for scenarios lie offline
data processing (e.g. I frequently use a FileSystemWatcher that updates
a database when a datafile is saved in a particular directory)

a serviced component (COM+) offers a different security model and is
accessible from non .NET code. it offers certain features like message
queueing, transactional processing, etc.

normally a specific design need will eliminate certain possibilities.
the 70-310 course books from both Microsoft and Que provide a good
starting point.

Thanks so much for the useful info. I still have lots of questions but
that definitely helps. What I'm mainly interested in is learning about
transactions within a closed domain. I'm not sure about the COM+ vs.
remoting but I'm thinking remoting is the next topic for me to learn
about. I'll keep the 70-310 course books in mind.

 

[stand__sure]

you'll actually want to learn about both then...

Good news, though!
(Thankfully) COM objects inherit from ServicedComponent which inherits
from ContextBoundObject which inherits from MarshalByRefObject (which
is the object from which a remotable object must inherit). so, what
you learn about remoting will be of use when doing COM+! You'll need
COM+ for doing transactions.

two decent articles are
http://whidbey.msdn.microsoft.com/l...rary/en-us/dndotnet/html/dotnetremotearch.asp
and
http://whidbey.msdn.microsoft.com/l...library/en-us/dnadvnet/html/vbnet05272003.asp

 

[trouling]

you'll actually want to learn about both then...

Good news, though!
(Thankfully) COM objects inherit from ServicedComponent which inherits
from ContextBoundObject which inherits from MarshalByRefObject (which
is the object from which a remotable object must inherit). so, what
you learn about remoting will be of use when doing COM+! You'll need
COM+ for doing transactions.

two decent articles are
http://whidbey.msdn.microsoft.com/l...rary/en-us/dndotnet/html/dotnetremotearch.asp
and
http://whidbey.msdn.microsoft.com/l...library/en-us/dnadvnet/html/vbnet05272003.asp

Thanks once again. I appreciate the time you invested directing me to
useful info.. I'll put it to good use.