A much better approach and one that coincides with a successful digital transformation is to consider your entire enterprise and integrate each business, application, data, and infrastructure system into your overall network without becoming too complex and unmanageable. Either way, your approach must integrate the following enterprise architecture principles to be successful:. In some cases, you can combine some of these systems successfully to address bottlenecks between them.
Figure -1, Enterprise Service Bus. Fortunately, there is an easy way to combine your middleware and SOA on the market already. It is called enterprise service bus ESB , and it is capable of addressing all your application integration architecture needs. But not all of them will come with the features, architectural capabilities, and cost effectiveness you need based on your desired enterprise integration pattern.
An enterprise integration pattern is a design template for integrating your application, business, and data systems together within your enterprise network. Currently, there are already 65 different integration patterns you can reuse to get your network up and running quickly without having to develop new code.
The following list provides a small sample of the these readily available integration patterns. You can find the complete list in the WSO2 product documentation. How the sender broadcasts an event to all interested receivers.
Thank you for your feedback. Sorry, we failed to record your vote. Please try again. You've read the top international reviews. Back to top. Get to Know Us. Clients Brief Form for House Properties v6. Buho Fiel. Mohammad Abu Bakar. Amit Pandey. Muhammad Hasan. Justin nguyen. Brad Bergeron. Harish Menon. Sasti Vel. Rafael Medina S. David is a language guy so expect a technology neutral, but formal treatment without being too academic.
There is a lot of ranting these days in the BPEL community about pi-calculus so I figured I stick the original reference on here. If you are not into reading academic texts but want to spot pi-calculus con artists, read JJ's excellent overview: www. The word 'model' may still appear a tad bit often, but the book does give a comprehensive treatment of the enterprise architecture considerations inherent in integration work.
It also goes into a little more technical detail than Linthicum -- we even get to see some UML diagrams! The book makes a good checklist of items to consider, but stops short of explaining how to actually construct working solutions. It's a pretty think book pages , so I would recommend picking one up from the Amazon marketplace for under 20 bucks. Middleware is a layer of software that lets business applications inter-operate, easing the problem of constructing complex applications, which can include market places, CRM and Internet access.
Middleware and Enterprise Application Integration is a practical introduction to the different forms of middleware RPC, message queues, hub and spoke, CORBA and Java and how they can be combined to produce complex architectures that are suited to business needs.
This book is aimed at consultants, managers and designers of complex business software for e-commerce, and shows how the new technologies can be made to meet new demands from business, without going into technical details. Taking Orders With Enricher. Now that we have an order ID to correlate order item messages, we need to define the completeness condition and the aggregation algorithm. Because we route all messages including invalid items to the Aggregator , the Aggregator can simply use the number of items in the order one of the fields in the order message to count until all order items arrive.
The aggregation algorithm is similarly simple. The combination of a Splitter , a Router and an Aggregator is fairly common. We refer to it as a Composed Message Processor. To simplify the picture, we insert the symbol for a Composed Message Processor into the original message flow diagram:.
Revised Order Process Implementation. Despite connecting the systems via messaging channels, fulfilling an order can take some amount of time. For example, we may be out of a certain item and the inventory system may be holding the inventory check message until new items arrive.
This is one of the advantages of asynchronous messaging: the communication is designed to happen at the pace of the components. Once both steps are completed, the Aggregator publishes the Validated Order message to initiate shipment and invoicing.
A long-running business process also means that both customers and managers are likely to want to know the status of a specific order. For example, if certain items are out of inventory, the customer may decide to process just those items that are in stock.
Tracking the status of an order with the current design is not so easy. Related messages flow through multiple systems. One of the advantages of a Publish-Subscribe Channel is that we can add additional subscribers without disturbing the flow of messages.
We can use this property to listen in to new and validated orders and store them into a Message Store. We could then query the Message Store database for the status see picture :. In situations where we use a Point-Point-Channel, we cannot simply add a subscriber to the channel because in a Point-to-Point Channel , each message can only be consumer by a single subscriber. However, we can insert a Wire Tap, a simple component that consumes a message off one channel and publishes it to two channels.
We can then use the second channel to send messages to the Message Store see picture. Tracking Messages with a Wire Tap. Storing message data in a central database has another significant advantage. In the original design each message had to carry all relevant data in order to continue processing the message down the line.
This additional data is necessary so that the resulting message still contains all data from the original order message. Now the Message Store is responsible for maintaining data related to the new message as well as the progress of the message within the process.
This data gives us enough information to use the Message Store to determine the next required steps in the process rather than connecting components with fixed Message Channel s. For example, if the database contains reply messages from both the inventory systems and the billing system, we can conclude that the order has been validated and send a message to the Shipping and billing system.
Instead of making this decision in a separate Aggregator component, we can do it right in the Message Store. Effectively, we are turning the Message Store into a Process Manager.
A Process Manager is a central component that manages the flow of messages through the system. The Process Manager provides two main functions:. Processing Orders With a Process Manager. This architecture turns the individual systems e. This increases reuse and allows for rapid changes and maintenance.
The services themselves can still be composed out of multiple steps, wired together via a message flow for example, using a Composed Message Processor to check inventory status for each order item , or orchestrated via a Process Manager. The Process Manager itself uses a persistent store typically files or a relational database to store data associated with each process instance.
In order to allow the Web Interface to query the status of an order we could send a message to the Process Manager or the order DB. However, checking status is a synchronous process — the customer expects the response right away. Because the Web Interface is a custom application, we decide to access the Order Database directly to query the order status. This form of Shared Database is the simplest and most efficient approach and we are always ensured that the Web Interface displays the most current status.
The potential downside of this approach is the fact that the Web Interface is tightly coupled to the database, a trade-off that we are willing to take.
The new architecture exposes all services to a common services bus so that they can be invoked from any other component. In order to participate in a Service-Oriented Architecture, each service has to provide additional functions.
For example, each service has to expose an interface contract that describes the functions provided by the service. Each request-reply service also needs to support the concept of a Return Address. This is important to allow the service to be reused in different contexts, each of which may require its own channel for reply messages. One difficulty in enabling these service functions is that many legacy systems were not build with features such as Return Address in mind. This Smart Proxy enhances the basic system service with additional capability so that it can participate in a Service-Oriented Architecture.
To do this, the Smart Proxy intercepts both request and reply messages to and from the basic service see picture. The Smart Proxy can store information from the request message e.
A Smart Proxy is also very useful to track quality of service e. WGRUS needs to deal with a number of addresses. We want to allow the customer to maintain all these addresses through the Web Interface to eliminate unnecessary manual steps. We can choose between two basic approaches to get the correct billing and shipping addresses to the billing and shipping systems:. The first option has the advantage that we can use an existing integration channel to transport the additional information.
A potential downside is the additional data flowing across the middleware infrastructure. We pass the address data along with every order even though the address may change much less frequently.
Because the billing and shipping systems are packaged applications they were not designed with integration in mind. As such, they are unlikely to be able to accept addresses with a new order but rather use the address that is stored in their local database. In order to enable the systems to update the address with the New Order message we need to execute two functions in the billing system and the shipping system : first, we need to update the address, and then we need to send the bill or ship the goods.
Because the order of the two messages matters we insert a simple Process Manager component that receives a New Order message which includes the current shipping and billing address0 and publishes two separate messages to the billing or shipping system see diagram. We update the address directly into the system database using a database Channel Adapter. We need to keep in mind that the Channel Adapter s require messages to be formatted in the proprietary formats used by the applications using so-called private messages.
Because the New Order message arrives in the canonical message format we need to perform a translation between the two formats.
We could build the transformation into the Process Manager but we actually prefer external Message Translator s so that the logic inside the Process Manager is not affected by the possibly complicated data format required by the applications. The second option uses data replication to propagate address changes to all affected systems independently of the New Order process.
Whenever the address information changes in the Web interface we propagate the changes to all interested systems using a Publish-Subscribe Channel.