Large-scale data centers often adopt more than one type of storage device, each with different storage capacity, I/O capability, and cost. Optimizing the performance-to-cost efficiency of such heterogeneous storage systems is of great practical importance (CapEx), and it is a classic problem in computer system design. The Vector-Sum Model (VSM) is a mental model widely-used by system administra...

Programming by Examples (PBE) involves synthesizing intended programs in an underlying domain-specific language from examplebased specifications. PBE systems are already revolutionizing the application domain of data wrangling and are set to significantly impact several other domains including code refactoring. There are three key components in a PBE system. (i) A search algorithm that can effi...

Although researchers have developed several ways to reason about the location of faults in spreadsheets, no single form of reasoning is without limitations. Multiple types of errors can appear in spreadsheets, and various fault localization techniques differ in the kinds of errors that they are effective in locating. Because end users who debug spreadsheets consistently follow the advice of fau...

Testing of concurrent software written in programming languages like Java and C/C++ is a highly challenging task due to the many possible interactions among threads. A simple, cheap, and effective approach that addresses this challenge is testing with noise injection which influences the scheduling so that different interleavings of concurrent actions are witnessed. In this paper, multiple resu...