Few basic BizTalk questions

Go lightly with that whole ‘expert’ stuff 😉

What happens when a message is being processed in one of the pipeline
statges or in an orchestration or while a message is being written to a
message box and the host or send/receive handler is restarted. How
messaging engine handles?

From my limited adapter development, when the service starts to ‘stop’ it notifies adapters to stop polling for or receiving messages. Any messages that are in the adapter, but have not been passed to the messaging engine (the bit that runs the pipeline and submits into the MsgBox) are allowed to complete and write to the MsgBox (thats why you might see a delay when stopping a BizTalk service). Messages that the adapter has polled for – but not submitted to the messaging engine – will not be removed from the source environment (i.e. the FILE adapter will only delete a file from the file system once it has been successfully submitted to the messaging engine). A few other members of the community with more adapter development experience will be able to clarify this description.

If any maps is configured in the receive location and send port, in
which stage of the recive and send pipeline the mapping transformation
is done?

The transform happens after the pipeline has completed processing on a Receive Port (not a Receive Location); and before the pipeline begins processing a message on a Send Port. Note, you can have multiple maps on either type of port and a message will be transformed by whichever map source schema matches the message.

I read about message interchanges. Is a flat file with multiple records can be considered as an interchange?

Yes. Furthermore, if the multiple records are split into individual messages for submission into the MsgBox, the individual messages will all be part of the same Interchange.

When a message without a namespace is processed by send/receive pipeline it fails. why?

It depends on the pipeline; I presume you’re talking here about a pipeline with an XmlDisassembler component or the XmlReceive pipeline (which contains said component). The XmlDisassembler (among other things) uses the Xml namespace and root node name to create the MessageType; It uses this value to lookup the schema in the Management Database in order to recognise and convert the input message into Xml, disassemble message Interchanges into individual messages (disassembling information is contained within the deployed schema) and promote properties. If it can’t build the MessageType (i.e. the namespace is missing) to resolve the schema, the component will fail.

What does XLANG engine handle a situation when an atomic scope is being executed and host instance is restarted?

Not entirely certain myself, but it will do one of two things: 1. it will kill the orchestration dead and re-run from the last check-point when the service restarts; or 2. it will attempt to let the atomic scope complete and write a check-point, when the service restarts, the orchestration will pickup from that point. I’d like to think that the process is the latter of the two.

HTH, Nick.