Cloud App Integration .com

A service-oriented architecture is only a few steps from the cloud. Read this for advice on how to transition from SOA to SaaS.

by Pierre Fricke, Red Hat

Ask anyone who works in a corporate environment about the challenges of sharing and accessing information. From moderate-size businesses to larger corporations, they’ll tell you those challenges are very real.

Thankfully, they can be circumvented by a service-oriented architecture (SOA) and cloud services, both of which help make logic and information more widely available for use across the enterprise.

That’s because a business that implements and relies on a SOA has already laid the groundwork for successful cloud integration. By definition, SOAs are meant to work with seemingly disparate components; and cloud services are no different. In fact, companies that have already grappled with standards-based integration of heterogeneous systems will likely have much greater flexibility in cloud deployment. That’s why it’s a good idea for businesses making the move toward the cloud to seriously consider a SOA. It can help make that move significantly easier.

The Path to Integration: Three Scenarios

Once a SOA is in place there are several options for IT managers in regards to cloud integration, each of which presents its own challenges and benefits. And while the first option – basic configuration – is currently the most popular, the other two – proxy service layer and cloud-based integration – have been coming on strong as managers become more comfortable with cloud services.

1. BASIC CONFIGURATION. With a basic configuration, one or more SaaS (Software-as-a-Service) applications are hosted in the cloud, while the rest of the organization’s infrastructure and integration fabric are behind the company firewall. The SaaS application may be a third party or custom application. Communications between internal systems and cloud-based SaaS will depend on the requirements of the business process. Common patterns include bi-directional Simple Object Access Protocol (SOAP) or Representational State Transfer (REST) calls, real-time data reads/writes, and one-way updates of local caches from a cloud-based store of reference data. Note that while this is currently the most adopted method, it’s really most appropriate when processes and integration are largely driven by internal systems. An emerging pattern is to leverage the new wire level protocol, Advanced Messaging Queueing Protocol (AMQP) for the messaging layer.

2. PROXY SERVICE LAYER. This method works well for organizations with a set of proxy services that decouple the internal integration fabric from services accessed by the cloud. The proxy service layer approach prevents the organization’s internal systems from being accessed by the outside world, and enables the organization to manage communications between proxy internal services. An organization might choose this scenario of buffering internal systems for multiple reasons, including concern for tight security, regulation compliance, and/or isolation and change control.

3. CLOUD-BASED INTEGRATION. This third option involves some integration fabric moving outside the firewall into the cloud. Cloud-based integration is the best option for managers seeking to insulate internal systems from process-to-process activity that needs to take place between cloud-resident applications. The applications will interact with systems behind the firewall only when needed. This approach is especially useful when the number of applications increases and inter-application traffic is high, creating a greater need for cloud hosting and on-demand resource allocation.

Like SOAs, Clouds Require Strong Governance

Regardless of where things start or how complex cloud application configurations might become over time, a comprehensive governance process, spanning technical and organizational realms, is an important component of success. Not only must dependencies among applications and components be carefully managed, but organizational dependencies and provision and scale resources for different components must also be carefully managed. And while large, multinational organizations may find these challenges quite familiar, even organizations of moderate size will need to focus on them.

For example, there are security and cross-geo concerns. Security issues can arise as work is done to reconcile software vendors’ security provisions with those of a cloud provider. And as with any wide-area deployment that crosses national boundaries, clouds demand close attention to national policies with regard to data movement and storage.

Bottom line: organizations need to put the processes in place to ensure that what they deploy meets all the requirements of stakeholders. Those processes begin with SOA — a crucial building block for successful cloud application integration. Because to maximize the value of cloud, organizations need more than cloud’s ability to add IT infrastructure agility. They need application agility facilitated by thoughtful application and data integration. A well-designed SOA—replete with comprehensive application and data services—is a key step toward effective application deployment and integration in the cloud.

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