The challenge

A major U.S. energy provider was experiencing slow application deployments and costly, error-prone updates due to its legacy DataPower deployment process. Additionally, the provider needed to migrate hundreds of business-critical services and applications to a new platform to meet regulatory requirements.

The energy provider's goal was to retire the DataPower stack by hosting its services on a hybrid cloud platform. To achieve this, it needed to establish modern DevOps principles, including implementing a robust Continuous Improvement/Continuous Deployment (CI/CD) platform and creating a dedicated support team. This would enable the provider to incrementally transform and deploy its existing applications to the new cloud platform. It'd also position the provider to use modern application development techniques and best practices moving forward.

The energy provider turned to WWT and VMware to assess and identify the best solution for its needs and handle implementation.

Aligning application platforms with cloud-native goals

After testing multiple platforms, the provider chose VMware Tanzu Application Services (TAS) to accelerate the company's cloud-native journey because it extracted the complexities of containers, infrastructure, storage and security from the development teams. TAS provided a stable environment for engineers to develop, test and deploy, and offered integrations with logging, monitoring, scaling and service catalog features for applications. TAS also provided a consistent cloud environment across public and private clouds.

For the CI/CD platform, WWT recommended Concourse to automate deployments due to its low learning curve and relative speed of deployment. Both Concourse and TAS allowed the energy provider to reuse its existing XML/XSLT for services with minimal changes, reduce the impact on applications consuming the responses and leave the smallest footprint possible on end users' applications.

Implementing the full solution

Through our strong partnership, WWT and VMware engineers worked together to deploy the new platforms and migrate applications from the legacy DataPower platform.

Platform deployment

The initial cloud provider selected was on-prem vSphere datacenter deployed via VxRail. The Concourse pipelines were used to deploy and maintain TAS as well as handle all aspects of the platform lifecycle, including downloading new artifacts from VMware and upgrading the pipeline when applicable. BOSH and TAS were installed to manage application deployments. Spring Data Power and Healthwatch Monitoring services were installed to provide observability into the modernized services and applications. See Figure 1.

High-level architecture of provider's Tanzu Application Services (TAS) platform.
Figure 1. High-level architecture of the provider's Tanzu Application Services (TAS) platform.

Application migration

The provider's DataPower platform hosted hundreds of business-critical services and acted on the XMLS/XSLT to transform XML documents for these services. The underlying premise is as simple as Newton's Cradle; each request that traversed through the gateways had to do so in a specific order, then traverse back up the stack once it reached the end gateway. Because each gateway had to act both independently as well as in a group, every service included a unique configuration file that specified instructions following a success or failure (see Figure 2).

XML Ingress Application diagram.
Figure 2. The provider's XML Ingress Application architecture. 

The engineering team devised and implemented the migration of the DataPower apps by leveraging most of the existing XML/XSLT with minimal changes. Making each gateway application a Spring Boot API allowed the request and response structure to remain the same because the response object didn't need to change for the end user.

The DataPower function library that acted on the request/response was rewritten in Java to support various pieces of business logic, where applicable. At the same time, an additional engineering team rewrote the XML transformations using Saxon. Because only minimal changes were made to the gateways, the team also revamped the configuration XML structure of the services.

Once the pipelines were working properly, each request could move through its requisite gateway and traverse back through the web once it reached the final step. To allow for instances of request errors, all error responses were wrapped in a soap envelope object that could traverse the web the same way as a successful response, ensuring business continuity. 


The energy provider's main goal was to migrate from the DataPower stack with zero or minimal impact to existing services. The new platform solution not only delivered a framework for the provider to seamlessly migrate its services, but it evolved those services to act as independent microservices through Springboot enablement. This approach allows the provider to scale microservices according to usage and manage its resources more efficiently to reduce operational costs. In other words, services with high utilization can now be scaled up while those with lower utilization can be scaled down. 

Additionally, WWT and VMware's platform solution has improved the provider's application deployment speed and reduced risk as it allows blue-green deployments -- a technique that reduces downtime by running two identical production environments. The solution also automates service deployments with real-time concourse pipelines for both the development and test environments.

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