What is Scalability?

February 5, 2007   8:58

Your system might work flawlessly at the beginning, but when the usage increases, the system resources will be stressed more and more causing your system to become slower. If the load becomes to high your solution might even start to produce error messages and it’s really time to expand your system.

If we need to expand our system to meet our business needs we are talking about scalability. We can expand by adding extra hardware, like extra servers, or by upgrading the existing hardware, like adding extra hard drives or CPU power. Note that we are not talking about optimizing our application’s software.

If we take a look at BizTalk Server we talk about scalability when we want to scale BizTalk to increase our throughput or if we want to reduce latency times. The BizTalk Server architecture enables us to scale-up and to scale-out.

• Scaling-out
  Adding extra hardware to our environment like servers to spread the work load. We can double the throughput by adding an identical server.
• Scaling-up
  Of course we can keep the solution inside the same box. We might try to improve our system by upgrading from a single-core CPU system to a dual-core CPU.

MSDN provides an useful piece of documentation on the situations and ways we can scale BizTalk.

Posted in What is | Featured url | Permalink | Post first comment

What is an Enterprise Service Bus?

February 4, 2007   21:24

There is quite a lot of confusion about the Enterprise Service Bus because the leading ESB-providing companies, like Gartner, Sonic and IBM made different definitions of the term.

When we compare all the different ESB solutions we can define a common set of characteristics that apply to an ESB:

• Brokered Communication
  The basic function of a ESB is to send data between processes on a single or multiple computers. The brokered communication is offered by the use of a software intermediary between the sender and the receiver.
• Routing
  Based on a predefined set of criteria ESBs are capable of routing messages to subscribers
• Endpoint Metadata
  ESBs normally maintain metadata that describe the service interfaces and message schemas.
• Basic Web Services
  An ESB supports basic Web service standards like SOAP, WSDL and foundational standards like TCP/IP and XML to communicate.

A lot of venders try to position their ESB as the single solution that solves all integration needs, but an ESB product can rarely do this as it misses features like business activity monitoring and business rules.

Does Microsoft deliver an ESB? No they do not. Of course you can build an ESB with the toolset from Microsoft, but they believe in delivering a broader set of important integration requirements that go beyond the ESB. Microsoft offers message validation and transformation, BAM, Business rules management and business process orchestration & management.

Posted in What is | Permalink | Post first comment