Case Studies / Legacy Application Migration from an On-Premise Proprietary Database

Legacy Application Migration from an On-Premise Proprietary Database

Karsun Solutions cloud practice delivers high-quality IT modernization solutions to its customers throughout the public sector. As an Amazon Web Services (AWS) Advanced Consulting Partner, we leverage the AWS catalog as a key component in our modernization efforts. Karsun Solutions’ Samir Bham describes one recent transformation below. This project migrated a legacy application from an on-premise database to AWS RDS. 

Key Challenge

Karsun Solutions serves customers at the General Services Administration (GSA). As part of GSA’s cloud initiative, our customer was looking to reduce licensing costs by migrating legacy applications from an on-premise proprietary database (Sybase) to AWS RDS (mySQL or PostgreSQL). Using our model, we successfully migrated several legacy applications to the cloud.


Karsun Solutions’ proposed solution was divided into two steps:

Step 1 – Assessment

We assessed all our applications for migration to the cloud with detailed assessment checklists. We then selected the relevant migration path for each scenario, such as lift and shift versus database migration approaches. Once applications are identified, we convert these applications to be database agnostic. This allows the applications to run using any relational database engine such as Sybase, or MySQL.

Step 2- Database Migration Service

Use enhanced AWS Data Migration Service (DMS) to successfully migrate Sybase ASE v15.7 database to MySQL RDS. Database migration involves two steps – Schema Conversion and Database Migration.

Schema Conversion Step

The Schema Conversion Tool (SCT) does not support Sybase as a Source database. In order to convert schema from Sybase to MySQL RDS, a two-step process was used.

Step 1 – Convert Schema from Sybase to Microsoft SQL

Microsoft provides a tool called SQL Server Migration Assistant (SSMA) that has support for converting schema from Sybase DB to MS SQL DB. The SSMA tool requires access to a Source and a Target database. To provide a target MS SQL database, an MS SQL RDS instance was created. Then the SSMA tool was used to convert the schema from Sybase to MS SQL.

Step 2 – Convert Schema from Microsoft SQL to MySQL

The SCT tool supports conversion of MS SQL schema to MySQL schema. For this step, the SCT tool was configured to connect to MS SQL RDS instance as Source database and MySQL RDS instance as Target database. Then the SCT tool was used to convert the schema. Once the schema is converted to the target database, the schema needs to be reviewed for the warnings that were generated during the process. Any manual fixes or updates are applied as required. After the schema has been finalized, it needs to be deployed on the target MySQL RDS instance.

Database Migration Step

The migration of existing data and the on-going replication sync is set up through the Database Migration Service (DMS). The DMS service allows migration between heterogeneous database engines and supports Sybase / SAP ASE version 15.7 and higher as the source database. As required by the customer, the target database is set to MySQL RDS instance. The DMS service requires setting up a Replication Instance, an EC2 instance that performs the data migration and replication. This replication instance can be configured using the DMS service AWS Console page. For more details on DMS, please see documentation from AWS here.

Project Outcomes

Karsun Solutions successfully converted CAMEO-SB applications – SWS, eOffer, eMod, CityPair Search to be database agnostic. And, migrated database from Sybase ASE to MySQL. Karsun Solutions IT modernization portfolio includes Modern Software Development, Cloud Solutions, and Data Solutions. Connect with us to learn more about teaming and partnership opportunities.