Implementing subscriber / publisher system with MSMQ with dynamic endpoints

Question

I'm trying to create a feedback system which all messages get posted to then published back to the correct subsystem. We are using queues quiet heavily and i want to make the subscriber code as clean as possible. I want to switch based off the message id i get into the feedback system and publish to its specific subscriber. i don't want to make a service for each subscriber to listen for messages.. i was thinking i could set up a queue for each subscriber and trigger to invoke a com+ component.. but i'm looking for a more modern way..

I was looking into NServiceBus but it seems i'd need to make a service/executable/webservice for each listening system ( its a little less work to make a C# dll and invoke a method) and i'm not sure if NServiceBus can handle dynamic endpoints based off a preloaded config ( loaded from a db ). WCF is also a choice.. it can handle dynamic endpoints for sure..

what do you think is the best solution for the lease amount of code/ scalable for new systems to subscribe?

Thanks

Answer 1

In case you are ok with online solutions you could take a look at the latest .NET Services SDK for Windows Azure which has queue service bus http://www.microsoft.com/azure/netservices.mspx It relies on WCF messages and supports routing etc. Some blog posts about this here http://vasters.com/clemensv/default.aspx

Another framework you could try is MassTransit http://code.google.com/p/masstransit/

Answer 2

It seems you're looking for a service host, rather than a message broker. If so, Microsoft's recommended way is to host your WCF services in IIS. They can still use MSMQ as transport, but the services themselves will be managed by IIS. IIS has evolved significantly since its early days as HTTP server, now it's closer to an application server, with its choice of transports (TCP, MSMQ, HTTP), pooling, activation, lifetime policies etc.

Although I find WCF+MSMQ+IIS somewhat overcomplicated this is the price you pay to play on the Microsoft field.

For nice and simple message broker, you can use Active MQ instead of MSMQ, it will give you message brokering as well as pub/sub. It's quite easy to work with in .NET, check this link out: http://activemq.apache.org/nms/