is public cloud the best destination for legacy applications?

The public cloud is used to run new applications built with the latest tools and the most trendy programming languages. Is it possible to run a legacy application that makes the enterprise data center a bit awkward on the public cloud?

If the application is in the update period, why is it only through a hardware upgrade or a cosmetic approach such as using a new GUI? Instead, why not go all out and rebuild applications on the most technologically advanced, scalable, and flexible cloud platforms? When it comes to operating costs rather than capital expenditure models, So much more should be done.

In fact, more and more IT professionals are thinking about this issue. Al Hilwa, director of the IDC Application development software research project, said IT professionals were interested in using the cloud as a destination for the legacy application modernization.

"There are workloads, such as applications for external users that can migrate well into the cloud," Hilwa said. "However, some considerations need to be evaluated before migrating existing legacy applications to the cloud."

Traps are everywhere.

This summer, Pabst Brewing moved its entire data center from San Antonio, Texas, to the Rackspace cloud platform, using its hybrid cloud and management services. Everything went pretty well before migrating two old applications, the Microsoft Dynamic Gperp system (previously called Great Plain) and the Revenue Management tool salient Margin minder.

Virtessential is an IT integrator whose CEO, Stephen Blake, witnessed the migration process, explaining that the two applications have been running for more than five years and have undergone several upgrades and patches. Pabst Brewing The company does not have access to the source installation files, nor does it have a document to view the record configuration changes.

Blake said: "No one knows what is installed, the application is a black box." ”

At the same time, like most managed service providers, Rackspace does not want to provide service-level agreements for less-known applications.

Blake said: "There won't be too many managed service providers MSP can quite flexibly say, ' Yes, we managed mirroring. ' They don't want to take the risk of supporting existing problems. ”

In contrast, service provider MSP typically only agrees to support new installed applications, which are managed using MSP's preferred tools. Virtessential uses the Application virtualization software provided by Appzero to bypass the problem, extract the application and its dependencies into a portable "virtual Application Device" package, and install it on the new operating system.

"These servers are like new structures, but they are not," Blake said. ”

Application extraction and migration process is less than 1 hours, since August in Rackspace operation of the application has not been a problem. Blake said that if they had not found Appzero before, migrating these two applications could add up to 3-4 weeks.

For Pabst, migrating legacy applications to the cloud was ultimately successful, but it wasn't always easy.

Crazy Multi-Tenant

The classic example is saleforce.com CRM and workday Payroll management outsourcing for companies that are gradually adding to their SaaS applications. Now some internal IT departments are thinking about continuing to refactor their internal applications into cloud-based multi-tenant applications-whether private SaaS is meaningful, as before.

Imagine, for example, the financial application developed by a car manufacturer for a national distributor. The application is written as a single tenant application that requires local installation, operation, and maintenance by local IT professionals at the dealership. This model is bound to be fraught with difficulties, as the distributor must resolve the failure and maintain the application.

In contrast to the above pattern, if you are rebuilt as a cloud-based, multi-tenant SaaS application, what is the effect of a car dealership that only needs to log in and be processed by the manufacturer for upgrades, maintenance, and new deployments?

Independent software developers have already provided local software to run at dealerships, and SaaS Software believes migrating to a multi-tenant environment is significant for business development.

EMAS Pro Company to provide school management software for college students, its senior vice president Andrei Sergeev said: "Is the right choice for multiple tenants?" Yes, because the goal is to optimize maintenance costs. "In simple terms, it is simpler for vendors and users to install and maintain tools based on SaaS."

SaaS also provides advanced functionality that is controlled by the user, Sergeev says, and it means high costs if the software is run locally at the dealership.

After some attempts at a local software solution, EMAS Pro recently started offering SaaS based tools called retention Pro to help schools identify students at risk of dropout. The service contains a number of different modules, Apache Tomcat, Rule engine, Business Analytics, and reporting engine, all of which are tightly integrated.

Sergeev said: "If you want to run these completely different components locally, then everything needs to be licensed, and the proposal will be expensive." He said that there are many use cases for private multi-tenant SaaS applications in the enterprise.

Unfortunately, refactoring legacy tenant applications to multiple tenants is easier said than done.

"This is a daunting task," said Brian Hoskins, the system software vendor LANDesk's main product manager. "Over the past three years, LANDesk has been SaaS with traditional help desk tools and is currently SaaS for systems and security management products."

Hoskins explains: Like many legacy local applications, LANDesk builds on Windows consoles that make direct calls to applications and the database tier. This mode cannot be run under the SaaS platform, so the company must rewrite all the code and complete all calls through the Web service.

(Responsible editor: The good of the Legacy)