Chapter 1. Introduction to Observability Tools

Bryan Cantrill’s foreword describes operating systems as “proprietary black boxes, welded shut to even the merely curious.” Bryan paints a realistic view of the not-too-distant past when only a small amount of the software stack was visible or observable. Complexity faced those attempting to understand why a system wasn’t meeting its prescribed service-level and response-time goals. The problem was that the performance analyst had to work with only a small set of hardwired performance statistics, which, ironically, were chosen some decades ago by kernel developers as a means to debug the kernel’s implementation. As a result, performance measurement and diagnosis became an art of inferencing and, in some cases, guessing.

Today, Solaris has a rich set of observability facilities, aimed at the administrator, application developer, and operating systems developer. These facilities are built on a flexible observability framework and, as a result, are highly customizable. You can liken this to the Tivo^[1] revolution that transformed television viewing: Rather than being locked into a fixed set of program schedules, viewers can now watch what they want, when they want; in other words, Tivo put the viewer in control instead of the program provider. In a similar way, the Solaris observability tools can be targeted at specific problems, converging on what’s important to solve each particular problem quickly and concisely.

^[1] Tivo was among the first digital media recorders for home media. It automatically records programs to hard disk according to users’ viewing and selection preferences.