So-called legacy software gets that name for a reason—it’s done enough for the organization over the years to earn a legacy enabling the business. But as GigaOm Analyst Ned Bellavance notes in a recently published GigaOm benchmark report (“Costs and Benefits of .NET Application Migration to the Cloud”), aging on-premises applications and infrastructure can work against businesses as they seek to scale, innovate, and grow.
A cloud modernization effort can change that. By migrating application logic and functionality to the cloud, enterprises avail themselves of the matchless scalability and managed services offered by major cloud providers. In the report, Bellevance lays out four options for organizations looking to cloudify their application portfolios.
Figure 1: Cloud Application Modernization Spectrum
- Rehost: “Lift-and-shift” virtual machines running on on-premises servers to cloud-based servers. Simple and quick.
- Replatform: Migrate application logic (say, ASP.NET apps) to a cloud-based Platform as a Service (PaaS) from an on-premises platform. Still simple and adds managed infrastructure, but requires minor code changes.
- Refactor: Review and restructure existing code to leverage cloud-based models and services. True cloud focus and deep PaaS integration comes at the cost of major code changes and re-architecting.
- Rewrite: Replace existing on-premises applications with cloud-native versions offering similar, if not enhanced functionality. Complex and time consuming, but the resulting cloud-native applications are loosely coupled and independently scalable.
Of these, replatforming offers considerable value and opportunity. Organizations avoid the cost and risk of new application development, while gaining access to powerful managed services and the raw scalability of the cloud.
In the report, Bellavance designed a series of benchmark tests designed to prove out real-world application performance across three, largely equivalent on-premises and cloud-based PaaS infrastructures:
- Windows VMs running on VMware
- Microsoft Azure using Azure App Service and Azure SQL Database
- AWS using Elastic Beanstalk, EC2, and Amazon RDS
His findings? Performance among the three options was roughly on par—unsurprising given that the test environment was designed for equivalency—but the costs varied markedly. The estimated cost of the tested on-premises infrastructure was $69,300, while the equivalent cost for AWS was $43,060. By contrast, for .NET shops moving to Azure, the cost was even lower—just $31,824.
The steep advantage versus AWS comes in large part from Azure Hybrid Benefit licensing, which enables Microsoft customers to apply their existing Windows Server and SQL Server licenses to Azure virtual machines and Azure SQL Database instances. And that can yield more than $10,000 in savings for an Azure migration compared to AWS.
Read the full GigaOm Report, “Costs and Benefits of .NET Application Migration to the Cloud.”
