Log Instrumentation Specifications and Low Overhead Logging

In CENS Technical Seminar , 0 pages , UCLA , July 2009.

NESL Technical Report #: TR-UCLA-NESL-200907-03

Severe resource constraints in bottom tier distributed embedded wireless systems hinder attempts to understand runtime behavior of deployed systems. Detailed diagnostic logs can provide the required insight, but must be obtained without violating bandwidth limitations, timing constraints, and other challenges of the target domain. This talk introduces the Log Instrumentation Specification (LIS) language that is used to describe focused logging tasks and drive the instrumentation of source code to collect the requested logs. The LIS language is easy for developers to use directly in their daily work flow and expressive enough to act as an intermediate language targeted by higher level analysis. The runtime logging support needed by LIS fits comfortably on low end sensing devices, allowing LIS to be applied to a wide range of systems. We will examine recent applications of LIS to diagnose problems in sensor networks and observe general runtime behavior. The end of the talk will focus on two new techniques for gathering call traces. The proposed techniques, local identifier logging and control flow logging, significantly reduce the bandwidth required to gather call traces compared to the standard call tracing technique currently used within the embedded sensor network community.

• Roy S Shea

• PDF file of presentation

• LIS : Log Instrumentation Specification
• LowLog : Low Bandwidth Call Trace Logging

Slides