What is BizTalk service instances? | BizTalk Interview Question

In BizTalk server there are two main type of processing components
  1. Orchestration Service Instance
  2. Messaging Service Instance

What is Orchestration Instance in BizTalk?

The orchestration instances is nothing but you develop an orchestration and deploy it in your environment. At run-time for every activation message you receive for that orchestration will create a new instance of that orchestration.

What is Messaging Instance? in BizTalk?

Messaging service instance is the service instance that’s created for your receive and send port at run time.

What are different states of BizTalk Service Instances?

The service instances gets instantiated like objects for classes and during the life time they go through various stages (states. Some of the common states include
  • Ready to Run
  • Scheduled
  • Dehydrated
  • Suspended, Resumable
  • Suspended, Non-resumable
  • Active
  • In Breakpoint
Each service instance state has its own value. System specific states like Active, Dehydrated, Ready to Run will change automatically as the message gets processed. But some states like suspended (resumable) and suspended (non-resumable) are failures that happen in system and an administrative action is required to rectify them.

For example, If the message sent to external web service and the web service is not available. In this case after all the retry the send port service instance will suspend itself with the state suspended (resumable). Once the web service is up and running again, the administrator can try to resume the suspended instance and the message will get processed. In some cases, the administrator can decide to terminate the service instance.

Large number of suspended service instances will bloat the message box database and adversely effect the overall performance of the environment. In some cases it could be an issue with the environment. for example If the host instance is not started and you get messages that kick off the service instances, then those instances will be in "Read to Run" state until the host instance is started. If the host instance is not started at all, then the service instances will get accumulate bloating the message box.

Rajesh MG

Rajesh MG is a software engineer, reader and writer from India. He has worked in various .Net projects.Follow him on twitter @rajeshmgonline