A Pattern-Based Code Transformation Approach for Cloud Application Migration

To support the migration of software applications to the cloud environment, cloud venders have proposed different migration methodologies and guidelines. Yet, most of them require human intervention, involving manually performing repetitive tasks. This paper proposes a pattern-based transformation approach for cloud application migration. The approach automatically modifies the source code of an application before the migration, to make it cloud-ready, and then transforms the source code to the target code in the cloud environment. The approach is supported by three key elements (patterns, rules and templates) and a process that systematically applies these elements. First, a pattern matching engine based on a regular expression processing technique is used to identify the parts of the source code that require modification and to extract the essential tokens from the source code for code transformation. Next, transformation rules are invoked to change the source code into the target code using a template, designed according to the target cloud environment. The proposed approach has been demonstrated on 19 open-source projects, by migrating them to Amazon Web Services.