J-Orchestra: Automatic Java Application Partitioning

J-Orchestra is an automatic partitioning system for Java programs. J-Orchestra takes as input Java applications in bytecode format and transforms them into distributed applications, running on distinct Java Virtual Machines. To accomplish such automatic partitioning, J-Orchestra uses bytecode rewriting to substitute method calls with remote method calls, direct object references with proxy references, etc. Using J-Orchestra does not require great sophistication in distributed system methodology--the user only has to specify the network location of various hardware and software resources and their corresponding application classes. J-Orchestra has significant generality, flexibility, and degree of automation advantages compared to previous work on automatic partitioning. For instance, J-Orchestra can correctly partition almost any pure Java program, allowing any application object to be placed on any machine, regardless of how application objects access each other and Java system objects. This power is due to the novel way that J-Orchestra deals with unmodifiable code (e.g., native code in the Java system classes). Additionally, J-Orchestra offers support for object migration and run-time optimizations, like the lazy creation of distributed objects.We have used J-Orchestra to successfully partition several realistic applications including a command line shell, a ray tracer, and several applications with native dependencies (sound, graphics).