CSR--PDOS: Improving System Reliability via Delta Execution

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Many applications require high reliability and availability. Unfortunately, software failures and administrative reconfiguration errors greatly reduce system reliability and availability, each contributing to 26-30% of system failures. To improve software reliability and reduce administrative errors, many reliability assurance techniques have been used at different stages of the software life cycle, including software testing, online software patch validation, partial replication-based fault detection and recovery, and online validation of administrative reconfigurations. Interestingly, all of the above reliability assurance tasks share a common characteristic: multiple almost-redundant executions (MARE). In other words, they all execute multiple versions/copies of the same software, each execution differing from the others only slightly in code segment, input, or configuration. An existing solution commonly used to perform MARE is to fully execute these almost-redundant runs sequentially (as done for software testing) or simultaneously (as done for online patch and reconfiguration validation) on the same or different machines. The inherent inefficiency of these approaches materializes in one of two ways large overhead or large waste of resources and human effort both negatively impacting the validation time and cost for reliability. To efficiently support the MARE used in performing various reliability assurance tasks, we propose a novel approach called delta execution and a comprehensive infrastructure to support it. To address the research challenges arising in delta execution, the proposed research tightly integrates innovations from multiple layers: operating sytsem, dynamic and static compilation, programming language support and various reliability assurance.