CODEWITHSUNDEEP
nservicebus
Brijesh
Brijesh

Reputation: 529

Instance Mapping - nServiceBus

We can use “Instance Mapping” to route message to same instance hosted on multiple physical servers. What would be the impact if one of the physical machine goes down due to any reason? Will nServiceBus framework will start routing message to remaining active “physical” machine?

Regards

Upvotes: 0

Views: 105

Answers (1)

Dennis van der Stelt
Dennis van der Stelt

Reputation: 2178

You're talking about MSMQ, which uses store & forward. It's first stored locally on the server, before it's forwarded to the actual machine.

There are two options to scale out

You chose Sender Side Distribution, I assume from your question, using endpoint instance mapping. In that same document, there's a section about the limitations which mentions:

Sender-side distribution does not use message processing confirmations (the distributor approach). Therefore the sender has no feedback on the availability of workers and, by default, sends the messages in a round-robin behavior. Should one of the nodes stop processing, the messages will pile up in its input queue. As such, nodes running in sender-side distribution mode require more careful monitoring compared to distributor workers.

So the messages keep being sent to the machine that is down. If it is entirely unreachable, the messages will remain in the Outgoing queue on the sender machine. Otherwise they'll be stored on the incoming queue on the processing machine.

Upvotes: 1

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