LDV: Light-weight database virtualization

We present a light-weight database virtualization (LDV) system that allows users to share and re-execute applications that operate on a relational database (DB). Previous methods for sharing DB applications, such as companion websites and virtual machine images (VMIs), support neither easy and efficient re-execution nor the sharing of only a relevant DB subset. LDV addresses these issues by monitoring application execution, including DB operations, and using the resulting execution trace to create a lightweight re-executable package. A LDV package includes, in addition to the application, either the DB management system (DBMS) and relevant data or, if the DBMS and/or data cannot be shared, just the application-DBMS communications for replay during re-execution. We introduce a linked DB-operating system provenance model and show how to infer data dependencies based on temporal information about the DB operations performed by the application´s process(es). We use this model to determine the DB subset that needs to be included in a package in order to enable re-execution. We compare LDV with other sharing methods in terms of package size, monitoring overhead, and re-execution overhead. We show that LDV packages are often more than an order of magnitude smaller than a VMI for the same application, and have negligible re-execution overhead.