How the absence of MSDTC can affect the implementation of BizTalk in the cloud

As announced in the PDC, the virtual machine role feature was added to Azure with the primary goal to move existing applications to the cloud. This allows us to upload our own VHD with the Operating System on it (Windows 2008 R2 Enterprise). This machine could have your application pre-packaged and installed. After doing this, you are now able to spin up multiple instances of that machine.

As stated in most discussions,

“MSDTC is not enabled on the cloud machines. There’s no workaround. But, in the cloud environment, there’s indeed no need to use MSDTC. The load balance is done automatically. In SQL Azure, when you use a normal BEGIN_TRANSACTION statement, the transaction may automatically be distributed, or it may not, depends on what the load balancer thinks best suits the operation.”

What this means?

◦BizTalk Server relies heavily on SQL Server and uses MSDTC to keep transactional state across databases and with the adapters.
◦SQL Azure does not support distributed transactions and also introduces more latency to the database queries.

So….

◦It won’t be possible to build a multi-machine BizTalk Server Group through the VM role.

BizTalk Server 2010 Feature Pack is now available!

You can download the feature pack from here.

One of the key requirements in development of cloud based applications is to be able to leverage existing on-premise assets by exposing them as web services. However, since most of the organizations are firewall protected, the on-premise web services are typically not accessible to external clients running outside the organization’s firewall, unless these web services are explicitly hosted in DMZ. More often than not, hosting services in the DMZ is a cumbersome process. Azure AppFabric Service Bus provides the capability to extend the reach of on-premise web services to external clients (without having to host them in the DMZ) in a secure way.

BizTalk Server 2010 AppFabric Connect for Services brings together the capabilities of BizTalk Server and Windows Azure AppFabric thereby enabling enterprises to extend the reach of their on-premise Line of Business (LOB) systems and BizTalk applications to cloud.