Microsoft Cloud Authors: Jim Kaskade, Lori MacVittie, Andreas Grabner, Janakiram MSV, Pat Romanski

Related Topics: Microsoft Cloud

Microsoft Cloud: Article

Goodbye Hub-and-Spoke, Hello ESB? Integration Architecture With BizTalk 2004

The popularity of the hub-and-spoke architecture, the traditional model for enterprise application integration (EAI), is declini

BizTalk Server is often positioned as a means to create a hub-and-spoke architecture. However, the popularity of the hub-and-spoke architecture, the traditional model for enterprise application integration (EAI), is declining. More and more architects and CIOs are targeting SOA (service-oriented architecture), and its infrastructural incarnation: the enterprise service bus (ESB). Does BizTalk fit into this ESB picture?

Integration Architecture
Trends and hype like SOA, EDA (event-driven architecture), and BPM (business process management) put integration on top of the list for most CIOs and IT managers. While all these trends hold assumptions about the ideal architecture for distributed computing, the differences in architectural approaches are not as clear to decision makers. Add that to the rapid changes evolving in the Microsoft platform, and it is easy to see that BizTalk Server 2004 can be positioned in different ways in your integration architecture.

In this article we are going to look at two different approaches for integration architecture, and we will see how BizTalk Server 2004 fits into these concepts.

Hub-and-Spoke Architecture
The first dominant integration architecture that broke with the cumbersome point-to-point application integration model was the so-called hub-and-spoke architecture, often referred to as "message broker."

Hub-and-spoke architectures consist of a centralized hub that accepts requests from multiple applications that are connected to the centralized hub as spokes. The spokes are connected with the central hub through lightweight connectors, which are constructed and deployed on top of existing systems and applications. One of the key goals of the hub-and-spoke architecture with connectors is to leave the current systems untouched and unchanged as much as possible.

Inside the hub there are capabilities for requirements such as message transformation, validation, routing, and asynchronous message delivery. Furthermore, most hub-and-spoke-based EAI solutions provide process management functionality to orchestrate interapplication message exchanges, and an administration console to monitor and track the workings of the hub.

See Figure 1

This integration architecture is the more traditional approach to connecting systems, and has been widely adopted because of its strengths:

  • It provides a focal point for applications and reduces the links between applications from n² links to n links
  • The hub provides a layer of insulation and functionality between the spokes, thus enabling spoke applications to be removed and replaced without other spokes being disrupted in any way
  • Because of this simplification of connecting applications, the model offers lower total cost of ownership
Despite its indisputable advantages and merits, hub-and-spoke models are not as popular as they used to be. One major problem is that the centralized hub presents a single point of failure in the overall architecture. If the central hub goes down, not a single message can still be sent or received. Attempts to overcome this problem by clustering multiple implementations of the hub are often stranded on the complexity of the architecture and on the overhead in administration.

Another important reason for this decline is that most hub-and-spoke-based EAI products are monolithic, expensive systems (especially when multiple implementations are deployed), based on proprietary standards. With the emergence of SOA, which is heavily based on open standards and loosely coupled, constituent services, the time has come for a new dominant integration architecture: the enterprise service bus.

The ESB Architecture
The ESB is often characterized as the backbone upon which to build SOA. There are numerous articles and white papers about the ESB, and they all have the following elements in common when describing what the ESB is: an ESB is seen as a distributed services architecture based on Web services standards, which delivers messaging middleware, intelligent routing, and XML transformation in conjunction with a flexible security framework and a management infrastructure for configuring, deploying, and monitoring the services. A typical ESB architecture looks somewhat like Figure 2.

At the heart of the ESB architecture is the enterprise services bus, a collection of middleware services that provides integration capabilities. Applications are connected to this logical bus through smart connectors, which encapsulate system functionality and provide a layer of abstraction between bus and application. In this smart connector we may find typical capabilities such as transformation services and security services. Through the use of open communication standards, connectivity between bus and applications is established.

The aforementioned description points out that an ESB is more a logical concept than it is a product. There are some vendors claiming that ESB is a product, but this perception comes more from a traditional view of integration architecture, which is based on products instead of standards.

One way or another, experts and analysts unanimously agree that for those companies and organizations pursuing an SOA or an EDA, the shift towards an ESB-based infrastructure is a major step in this evolvement.

Hub-and-Spoke vs ESB
An ESB provides the same functionality as a "traditional" broker in a hub-and-spoke architecture. The pictures we have seen of both the hub-and-spoke architecture and the ESB architecture are also very much alike. The key difference however is that the capabilities in an ESB are themselves SOA-based, since they are spread out across the bus in a distributed fashion, and the capabilities are hosted in separately deployable service containers. This is a fundamental difference in architecture.

The distributed nature of the ESB Services allows for the selective deployment of integration broker functionality exactly where you need it, with no additional overbloating where it's not needed. The ESB container model allows for the independent scalability of integration components, which are plugged into your SOA as event-driven services on an as-needed basis.

More Stories By Loek Bakker

Loek Bakker is a senior consultant at Capgemini, the Netherlands. He specializes in architecture, SOA, and Microsoft.NET. Within Capgemini he is a lead architect for BizTalk-based integration solutions.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

Most Recent Comments
.NET News Desk 09/12/05 05:06:21 PM EDT

Goodbye Hub-and-Spoke, Hello ESB? Integration Architecture With BizTalk 2004. BizTalk Server is often positioned as a means to create a hub-and-spoke architecture. However, the popularity of the hub-and-spoke architecture, the traditional model for enterprise application integration (EAI), is declining. More and more architects and CIOs are targeting SOA (service-oriented architecture), and its infrastructural incarnation: the enterprise service bus (ESB). Does BizTalk fit into this ESB picture?

@ThingsExpo Stories
SYS-CON Events announced today that Enzu will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to focus on the core of their online busine...
WebRTC sits at the intersection between VoIP and the Web. As such, it poses some interesting challenges for those developing services on top of it, but also for those who need to test and monitor these services. In his session at WebRTC Summit, Tsahi Levent-Levi, co-founder of testRTC, reviewed the various challenges posed by WebRTC when it comes to testing and monitoring and on ways to overcome them.
The explosion of new web/cloud/IoT-based applications and the data they generate are transforming our world right before our eyes. In this rush to adopt these new technologies, organizations are often ignoring fundamental questions concerning who owns the data and failing to ask for permission to conduct invasive surveillance of their customers. Organizations that are not transparent about how their systems gather data telemetry without offering shared data ownership risk product rejection, regu...
Join IBM November 2 at 19th Cloud Expo at the Santa Clara Convention Center in Santa Clara, CA, and learn how to go beyond multi-speed it to bring agility to traditional enterprise applications. Technology innovation is the driving force behind modern business and enterprises must respond by increasing the speed and efficiency of software delivery. The challenge is that existing enterprise applications are expensive to develop and difficult to modernize. This often results in what Gartner calls...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, will discuss the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They will also review two "free infrastruct...
WebRTC defines no default signaling protocol, causing fragmentation between WebRTC silos. SIP and XMPP provide possibilities, but come with considerable complexity and are not designed for use in a web environment. In his session at @ThingsExpo, Matthew Hodgson, technical co-founder of the Matrix.org, discussed how Matrix is a new non-profit Open Source Project that defines both a new HTTP-based standard for VoIP & IM signaling and provides reference implementations.
Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, will deep dive into best practices that will ensure a successful smart city journey.
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessi...
November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Penta Security is a leading vendor for data security solutions, including its encryption solution, D’Amo. By using FPE technology, D’Amo allows for the implementation of encryption technology to sensitive data fields without modification to schema in the database environment. With businesses having their data become increasingly more complicated in their mission-critical applications (such as ERP, CRM, HRM), continued ...
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
SYS-CON Events announced today that Cloudbric, a leading website security provider, will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Cloudbric is an elite full service website protection solution specifically designed for IT novices, entrepreneurs, and small and medium businesses. First launched in 2015, Cloudbric is based on the enterprise level Web Application Firewall by Penta Security Sys...
Virgil consists of an open-source encryption library, which implements Cryptographic Message Syntax (CMS) and Elliptic Curve Integrated Encryption Scheme (ECIES) (including RSA schema), a Key Management API, and a cloud-based Key Management Service (Virgil Keys). The Virgil Keys Service consists of a public key service and a private key escrow service. 

Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
SYS-CON Events announced today that MathFreeOn will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. MathFreeOn is Software as a Service (SaaS) used in Engineering and Math education. Write scripts and solve math problems online. MathFreeOn provides online courses for beginners or amateurs who have difficulties in writing scripts. In accordance with various mathematical topics, there are more tha...
In an era of historic innovation fueled by unprecedented access to data and technology, the low cost and risk of entering new markets has leveled the playing field for business. Today, any ambitious innovator can easily introduce a new application or product that can reinvent business models and transform the client experience. In their Day 2 Keynote at 19th Cloud Expo, Mercer Rowe, IBM Vice President of Strategic Alliances, and Raejeanne Skillern, Intel Vice President of Data Center Group and ...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
@ThingsExpo has been named the Top 5 Most Influential Internet of Things Brand by Onalytica in the ‘The Internet of Things Landscape 2015: Top 100 Individuals and Brands.' Onalytica analyzed Twitter conversations around the #IoT debate to uncover the most influential brands and individuals driving the conversation. Onalytica captured data from 56,224 users. The PageRank based methodology they use to extract influencers on a particular topic (tweets mentioning #InternetofThings or #IoT in this ...
There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
"We've discovered that after shows 80% if leads that people get, 80% of the conversations end up on the show floor, meaning people forget about it, people forget who they talk to, people forget that there are actual business opportunities to be had here so we try to help out and keep the conversations going," explained Jeff Mesnik, Founder and President of ContentMX, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York City, NY.
Intelligent machines are here. Robots, self-driving cars, drones, bots and many IoT devices are becoming smarter with Machine Learning. In her session at @ThingsExpo, Sudha Jamthe, CEO of IoTDisruptions.com, will discuss the next wave of business disruption at the junction of IoT and AI, impacting many industries and set to change our lives, work and world as we know it.