Section 1.3. About Part One

1.3. About Part One

In this book, we present specific examples of how and when to use the various tools and utilities in order to understand system behavior and identify problems, and we introduce some of our analysis concepts. We do not attempt to provide a comprehensive guide to performance analysis; rather, we describe the various tools and utilities listed previously, provide extensive examples of their use, and explain the data and information produced by the commands.

We use terms like utilization and saturation to help quantify resource consumption. Utilization measures how busy a resource is and is usually represented as a percentage average over a time interval. Saturation is often a measure of work that has queued waiting for the resource and can be measured as both an average over time and at a particular point in time. For some resources that do not queue, saturation may be synthesized by error counts. Other terms that we use include throughput and hit ratio, depending on the resource type.

Identifying which terms are appropriate for a resource type helps illustrate their characteristics. For example, we can measure CPU utilization and CPU cache hit ratio. Appropriate terms for each resource discussed are defined.

We've included tools from three primary locations; the reference location for these tools is at http://www.solarisinternals.com.

• Tools bundled with Solaris: based on Kstat, procfs, DTrace, etc.

• Tools from solarisinternals.com: Memtool and others.

• Tools from Brendan Gregg: DTraceToolKit and K9Toolkit.

1.3.1. Chapter Layout

The next chapters on performance tools cover the following key topics:

• Chapter 2, "CPUs"

• Chapter 3, "Processes"

• Chapter 4, "Disk Behavior and Analysis"

• Chapter 5, "File Systems"

• Chapter 6, "Memory"

• Chapter 7, "Networks"

• Chapter 8, "Performance Counters"

• Chapter 9, "Kernel Monitoring"

This list can also serve as an overall checklist of possible problem areas to consider. If you have a performance problem and are unsure where to start, it may help to work through these sections one by one.