BPF Performance Tools book

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BPF Performance Tools (book)




New tools developed for this book colored red.


Draft copy


eBook preview first 100 pages

This is the official site for the book BPF Performance Tools: Linux System and Application Observability, published by Addison Wesley (2019). This book can help you get the most out of your systems and applications, helping you improve performance, reduce costs, and solve software issues. Here I'll describe the book, link to related content, and list errata and updates.

The ebook is available on Amazon.com, InformIT (eBook), and Safari here and here. The paper book will be released in December 2019 (see Amazon.com). ISBN-13: 9780136554820.

The Amazon preview of the Kindle book shows the first 100 pages out of this 880 page book.

As an example new tool from the book, readahead.bt provides a new view of file system read ahead performance: the age of read-ahead pages when they are finally referenced, and unused read-ahead pages while tracing:

# readahead.bt
Attaching 5 probes...
^C
Readahead unused pages: 128

Readahead used page age (ms):
@age_ms: 
[1]             2455 |@@@@@@@@@@@@@@@                                     |
[2, 4)          8424 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
[4, 8)          4417 |@@@@@@@@@@@@@@@@@@@@@@@@@@@                         |
[8, 16)         7680 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@     |
[16, 32)        4352 |@@@@@@@@@@@@@@@@@@@@@@@@@@                          |
[32, 64)           0 |                                                    |
[64, 128)          0 |                                                    |
[128, 256)       384 |@@                                                  |

The book covers many of the existing tools as well, for example, tcplife for efficiently logging TCP session details:

# tcplife
PID   COMM   LADDR          LPORT RADDR          RPORT TX_KB RX_KB MS
4169  java   100.1.111.231  40158 100.2.116.192  6001      7    33 3590.91
4169  java   100.1.111.231  56940 100.5.177.31   6101      0     0 2.48
4169  java   100.1.111.231  6001  100.2.176.45   49482     0     0 17.94
4169  java   100.1.111.231  18926 100.5.102.250  6101      0     0 0.90
4169  java   100.1.111.231  44530 100.2.31.140   6001      0     0 2.64
4169  java   100.1.111.231  44406 100.2.8.109    6001     11    28 3982.11
34781 sshd   100.1.111.231  22    100.2.17.121   41566     5     7 2317.30
[...]

The book explains these and over 150 other BPF tools, as well as summarizing over 30 traditional performance analysis tools (top, vmstat, iostat, perf, Ftrace, etc) so that you can use the right tool for the job.

What is BPF?

Berkeley Packet Filter (BPF) is an in-kernel execution engine that processes a virtual instruction set, and has been extended recently (aka eBPF) for providing a safe way to extend kernel functionality. In some ways, eBPF does to the kernel what JavaScript does to websites: it allows all sorts of new applications to be created. BPF is now used for software defined networking, observability (this book), security enforcement, and more. The main front-ends for BPF performance tools are BCC and bpftrace. BPF itself is also becoming a technology name, and no longer an abbreviation.

Operating Systems

Extended BPF is a built-in Linux kernel technology, added in parts since 3.18. At least Linux 4.9 is necessary to utilize the tools in this book. All Linux distributions can use the BPF tools (Ubuntu, CentOS, Fedora, Red Hat, etc): although the status of BCC and bpftrace varies for each distribution. Some have packages, others still require a build from source. See the install instructions for BCC and bpftrace.

Other operating systems including BSD (where BPF originated) are not covered in this book. As extended BPF is being ported elsewhere, a future edition of this book may cover more than Linux.

Audience

This book is primarily for engineers, developers, and support staff in enterprise and cloud environments. No programming is required, unless you want to, as you can use this book as either:

This book is also useful for students as a way to learn system internals in an interactive way: you can run and develop tools to examine the workings of the system.

Tools

Over 150 BPF tools are covered in the book, for performance analysis, troubleshooting, and other uses (e.g., security forensics). These tools provide observability for CPUs, memory, disks, file systems, networking, languages, applications, containers, hypervisors, security, and the Linux kernel. To explain how to analyze different languages, three types of execution are studied: compiled, JIT-compiled, and interpreted, using C, Java, and the bash shell as examples. The same approaches can be applied to other languages, and a summary for Node.js, C++, and Golang are included.

To cover all these targets, many new tools needed to be developed for this book. The diagram on the top right shows these new tools colored red. The source to these is included in the book, and can also be found here:

The /originals directory contains an as-is snapshot of the published tools, and /updated contains those tools plus updated versions.

Table of Contents

Related Content

Errata

1st Printing

Digital conversion errors:

Updates

These are updates to BPF, many of which were mentioned in the book as "planned" and have since been implemented.

Thanks to all the reviewers, and to Deirdré Straughan for editing another one of my books!


Last updated: 13-Dec-2019