Manual Addressing

How can a client application control the To address of an outgoing message? I don't want to create a new proxy for every connection.

This is one of those topics that I could have sworn that I wrote about but can't find any evidence of it online. Actually, I was going through some papers the other day and found notes for five or six topics that got sketched out but never published. I'm guessing that that's what happened to the advice on manual addressing. In light of this discovery, today I'll focus solely on manual addressing from a service perspective and leave the channel perspective on manual addressing for another time.

Manual addressing controls the stamping of addressing headers on outgoing messages. Normally, the transport just overwrites the message headers with whatever addressing information it's been configured with. No amount of fiddling at the service level will change that behavior because any existing addressing headers get obliterated when going through the transport.

Some transports, such as HTTP, have a setting on the binding element called ManualAddressing that turns off this automatic stamping behavior. Other transports, such as TCP, will ignore your new header value with manual addressing because it's not possible to redirect an existing TCP connection on a per-message basis. This isn't a problem for HTTP because every HTTP request can have its own connection if desired. Support for manual addressing of messages is purely a transport-specific feature.

The answer to the question therefore comes in three parts. First, make sure that the transport that you're using supports some form of manual addressing. If not, then you're out of luck in terms of sending messages to different destinations without creating some new object on a per-destination basis. Second, turn on that manual addressing option to prevent the automatic application of addressing headers during message sends. Third, use whatever method you want to apply your own addressing headers to the outgoing message. If you're just making service calls on a proxy, then you'll want to use something like this:

 OperationContext.Current.OutgoingMessageHeaders.To = this.replyTo.Uri;

If you're creating Message instances yourself, then you'll want to apply your addressing headers to the message header collection and so on.

Next time: MSMQ: Net vs Integration

Update: I clarified what TCP's lack of support for manual addressing means.

Comments

• Anonymous
  January 09, 2007
  I have a machine with multiple network cards. How do I control which networks my service listens on?

• Anonymous
  January 09, 2007
  blog deja vu... http://ebersys.blogspot.com/2006/12/sign-that-youve-been-posting-too-much.html

• Anonymous
  February 19, 2007
  I haven't forgotten about the goal to put together a table of contents for all of these articles. The

• Anonymous
  April 02, 2007
  Can I write a point-to-point router service by setting the Via property for outgoing messages? Like most