BizTalk Mutiple Host Instance Affecting Each other

I'm very new to BizTalk. I have a problem here:

Both PC12-4 and PC12-0 are working on the same project at the same time. If they change code and do test at the same time, the result will be affected by each other. From http://msdn.microsoft.com/en-us/library/aa561042.aspx I noticed that it's not recommended to have multiple host instances in one host.

I wonder is there any way to allow the result not affected? The aim is for multiple people working and testing the same program at the same time. Because we finished one part of the application and the users want to test it now while we are doing the second part. The users test results are affected by our new changes.

Many thanks!

If I interpret you situation correctly, the problem is not with the Host/Instance configuration, rather, what you are trying to do, use PC12-4 and PC12-0 for the same project but different purposes, DEV and TEST, is not supported.

Meaning, you can't have different versions of the same app installed on two different servers in the same Group. There is no way around this and there is no way to make it work in the way you want. Sorry.

What you need to do is split PC12-4 and PC12-0 into two separate BizTalk Groups, meaning two separate sets of SQL Server databases in two separate instances of SQL Server. One Group for DEV and the other for user TEST.

But, even then, you may still have problems because multiple developers sharing a single BizTalk Group/Server is not workable scenario. Each developer should have their own full stack, Windows, SQL Server, BizTalk Server and Visual Studio. The best way to achieve this is dedicated developer VM's.