MSMQ General question 1

[nhidalgo]

My supervisor was told we should use MSMQ to have about 38 pc's send files and messages to a central computer. I don't know anything about this process. Can anyone give me a few links that explain what MSMQ is and what it is capable of Or any good books on the subject.

Nick

 

[BobRodes]

Basically, you can think of MSMQ as sort of emails for databases. An example of when you might use it is in an airline application. Say when the airline creates a flight, it also wants to order meals for the passenger. The meal vendor doesn't need to be online all the time to see orders; they might only need to pick up orders once a day. So, the ticketing process posts orders to the message cue each time they have a ticket, and once a day, the vendor clears the queue and posts the orders to their db.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnanchor/html/messgqueuecomps.asp

will tell you all about it.

HTH

Bob

 

[chiph]

Another way to think of it is a pipe connecting two processes, even if they're on different machines. You put a message in one end, and it comes out the other. Order is preserved.

It generally performs pretty well. I've seen ~200 small messages a second through one.

Chip H.


____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first

 

[nhidalgo]

what we are looking to due is transmit POS transaction data from 38 remote locations to our main office, the files would be about 3k. I was going to just right a vb app that would cycle through all of the stores and just do a file copy, but we were told that msmq would provide a better solution. Is this posssible with msmq?

Thanks for the replies

nick

 

[dilettante]

As I recall the "payload" maximum for an individual MSMQ Message is something like 2MB of data.

MSMQ offers advantages over a simple "pipe" as well. A machine sending data to an MSMQ Queue on another machine doesn't even need to have a continuous connection to the server machine. The local machine will hold the data until a path does exist, and then just pump it over the link.

You can also make MSMQ Queues transactional, insuring once and only once delivery.

MSMQ Triggers even offer a mechanism whereby server applications get fired up automatically to process queued messages as they arrive.

All of this comes with only fairly simple application code. MSMQ Queued Components offers yet another way to use MSMQ instead of explicitly interacting with the ActiveX classes wrapping the MSMQ API.

MSMQ can get to be a big topic on its own, involving Active Directory domains, relay servers, journaling, and such. It is also possible to use it in simpler scenarios though, including Workgroup networks or even cross-domain networking.

I'd characterize it more as "email for applications" but it goes much further than that.

If you have installed the VB6 Samples, you'll find a starter MSMQ "workflow" application there.

Here is a brief introduction: Using Visual Basic to Integrate MSMQ into Your Distributed Applications.

The MSDN Library has reference material on the subject.

 

[chiph]

Yeah, there's a lot more to MSMQ than meets the eye. If you've never used it, you'll want to buy a couple of books on the topic.

Chip H.


____________________________________________________________________
If you want to get the best response to a question, please read FAQ222-2244 first

 

[BobRodes]

<The MSDN Library has reference material on the subject.

The link I sent you is the top page for the reference material.

Bob

 

[nhidalgo]

Thanks for the replies, i used the msdn link to create a test project. I am going to by a book on the subject. Thanks for the help

Nick