Availability assessment of SunOS/Solaris Unix Systems based on Syslogd and wtmpx logfiles : a case study

TL;DR

This study evaluates the availability of SunOS/Solaris systems over four years by analyzing syslogd and wtmpx logs, demonstrating that combining these sources yields more accurate system availability estimates.

Contribution

It introduces a method for combining syslogd and wtmpx logs to improve the accuracy of system availability assessments in Unix environments.

Findings

Combined logs improve availability estimation accuracy.

Syslogd logs alone may be incomplete.

Auxiliary data enhances failure detection.

Abstract

This paper presents a measurement-based availability assessment study using field data collected during a 4-year period from 373 SunOS/Solaris Unix workstations and servers interconnected through a local area network. We focus on the estimation of machine uptimes, downtimes and availability based on the identification of failures that caused total service loss. Data corresponds to syslogd event logs that contain a large amount of information about the normal activity of the studied systems as well as their behavior in the presence of failures. It is widely recognized that the information contained in such event logs might be incomplete or imperfect. The solution investigated in this paper to address this problem is based on the use of auxiliary sources of data obtained from wtmpx files maintained by the SunOS/Solaris Unix operating system. The results obtained suggest that the combined use of wtmpx and syslogd log files provides more complete information on the state of the target systems that is useful to provide availability estimations that better reflect reality.