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Performance Tuning for Linux Servers
swsuehr writes "Performance Tuning for Linux Servers provides information and resources for Linux administrators looking for a guide to the background, options, and commands available for enhancing the performance of a Linux server." Clear enough -- but read on for Suering's review of the book to see if it might help you at that task.
Performance Tuning for Linux Servers
author
Johnson, Huizenga, Pulavarty, et al
pages
547
publisher
IBM Press/Pearson
rating
8
reviewer
Steve Suehring
ISBN
013144753X
summary
Information and techniques for performance enhancement of Linux servers.
The Particulars
The book is 547 pages. Of that total, 507 are the content of the book while 13 pages are used for an Appendix. The Appendix is provides a look at some of the tunable parameters in the Linux kernel through interfaces such as sysctl and /proc. This appendix alone makes the book good reference material. The book is divided into five sections including an overview of Linux, performance analysis tools, system tuning, performance characterization, and case studies. The book covers the 2.6 kernel series and the 2.4 series where appropriate.
The book is published under the IBM Press brand but is most definitely not an IBM-centric book. The book is largely, though not completely, distribution neutral. Distribution neutrality means that you don't have to be running any certain flavor of Linux in order to follow the examples in the book. The book covers Red Hat Enterprise and Novell SuSE Linux Enterprise but does so in a non-intrusive manner such that most of the references are simply used to illustrate a certain point rather than requiring the reader to follow a step-by-step process. For instance, BSD and System V initialization processes are both covered in Chapter 1.
The book wasn't written by a single author. In fact, it appears to be the work of numerous authors, each contributing certain sections or chapters. With this type of format it's very easy for a book to lack cohesiveness. This isn't the case with Performance Tuning for Linux Servers where the material shares the same tone throughout. Truthfully, I didn't know that there were so many contributors until I was writing the review, that's how well the material flows together.
A Look Inside
Performance Tuning for Linux Servers combines both theory and practice. The essential background information is given for each subject but interwoven with practical knowledge. For example, Chapter 8 describes tuning of the scheduler including a list of tunable parameters with both a description and an effect. From p. 193:
"MAX_SLEEP_AVG"
"Description: The value of this parameter is the maximum sleep average a task can accumulate for the purposes of calculating the scheduling bonus. A task with this sleep average gets the maximum bonus as indicated by PRIO_BONUS_RATIO." "Effect: If the value of this parameter is increased, tasks need to accumulate a larger sleep average to get the same priority bonus. Decreasing the value has the opposite effect."
Several performance analysis tools are covered in some detail. These can be invaluable when trying to track down performance problems with a Linux server. One of the advantages to Linux is that it doesn't need to be rebooted in order to "clean up" as other operating systems need from time to time. Using these performance analysis tools, the administrator can track down exactly what is causing a bottleneck or resource issue on the server.
The performance analysis tools are mainly discussed in chapter 4, "System Performance Monitoring." The chapter is broken down into sections based on the type of resource to be analyzed. The sections include CPU Utilization where general tips such as `cat /proc/cpuinfo` are given in addition to detailed discussion of vmstat, top, gtop, and sar (part of the sysstat package). The next section discusses Memory Utilization which looks at some of the information available through /proc before detailing ps and vmstat. I/O Utilization is the next section where iostat is discussed along with another look at sar. Finally, Network Utilization rounds out this chapter with brief discussion of commands such as arp, ifconfig, and other basic network commands before detailing netstat. Throughout this chapter examples of output are given for many commands.
The authors do a great job at not only condensing the material but, more importantly, they also bring some highly technical concepts down to the reader's level. Take for example chapter 2, "Kernel Overview" where a detailed discussion of the architecture of the Linux kernel is given.
Part III of the book is devoted to system tuning (it's aptly titled "System Tuning"). This section of the book provides detailed background information so that the administrator can make educated decisions about what to tune. For example, chapter 9 is devoted to the Linux virtual memory subsystem and includes a discussion of not only how virtual memory is handled in the kernel (including new features for the 2.6 series) but also the tunable parameters for virtual memory.
Within Part III are chapters on the aforementioned virtual memory subsystem, the scheduler, I/O subsystems, file systems, network, IPC, and code tuning. Chapter 11, "File System Tuning", opens with a discussion of the basic terms in file systems before continuing on with discussion of specific file systems including ext2, ext3, ReiserFS, JFS, and XFS.
Part IV of the book looks at characteristics of Linux server applications. Doing so helps to frame the discussion of the different attributes important to tuning the server for each of these applications. The last section of the book, beginning of page 405, is devoted to case studies.
One final highlight for the book is that most chapters include a detailed references section with pointers to relevant information for that chapter. Some chapters have more references than others. The references might be anything from a man page to a magazine article to a book and a few other resources.
The combination of both detailed background information along with practical techniques, all of which are explained clearly, makes Performance Tuning for Linux Servers a great resource for Linux administrators who want to squeeze optimal performance from their server. I believe the book has a good shelf life that will keep it on my bookshelf for quite a long time.
You can purchase Performance Tuning for Linux Servers from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
The Particulars
The book is 547 pages. Of that total, 507 are the content of the book while 13 pages are used for an Appendix. The Appendix is provides a look at some of the tunable parameters in the Linux kernel through interfaces such as sysctl and /proc. This appendix alone makes the book good reference material. The book is divided into five sections including an overview of Linux, performance analysis tools, system tuning, performance characterization, and case studies. The book covers the 2.6 kernel series and the 2.4 series where appropriate.
The book is published under the IBM Press brand but is most definitely not an IBM-centric book. The book is largely, though not completely, distribution neutral. Distribution neutrality means that you don't have to be running any certain flavor of Linux in order to follow the examples in the book. The book covers Red Hat Enterprise and Novell SuSE Linux Enterprise but does so in a non-intrusive manner such that most of the references are simply used to illustrate a certain point rather than requiring the reader to follow a step-by-step process. For instance, BSD and System V initialization processes are both covered in Chapter 1.
The book wasn't written by a single author. In fact, it appears to be the work of numerous authors, each contributing certain sections or chapters. With this type of format it's very easy for a book to lack cohesiveness. This isn't the case with Performance Tuning for Linux Servers where the material shares the same tone throughout. Truthfully, I didn't know that there were so many contributors until I was writing the review, that's how well the material flows together.
A Look Inside
Performance Tuning for Linux Servers combines both theory and practice. The essential background information is given for each subject but interwoven with practical knowledge. For example, Chapter 8 describes tuning of the scheduler including a list of tunable parameters with both a description and an effect. From p. 193:
"MAX_SLEEP_AVG"
"Description: The value of this parameter is the maximum sleep average a task can accumulate for the purposes of calculating the scheduling bonus. A task with this sleep average gets the maximum bonus as indicated by PRIO_BONUS_RATIO." "Effect: If the value of this parameter is increased, tasks need to accumulate a larger sleep average to get the same priority bonus. Decreasing the value has the opposite effect."
Several performance analysis tools are covered in some detail. These can be invaluable when trying to track down performance problems with a Linux server. One of the advantages to Linux is that it doesn't need to be rebooted in order to "clean up" as other operating systems need from time to time. Using these performance analysis tools, the administrator can track down exactly what is causing a bottleneck or resource issue on the server.
The performance analysis tools are mainly discussed in chapter 4, "System Performance Monitoring." The chapter is broken down into sections based on the type of resource to be analyzed. The sections include CPU Utilization where general tips such as `cat /proc/cpuinfo` are given in addition to detailed discussion of vmstat, top, gtop, and sar (part of the sysstat package). The next section discusses Memory Utilization which looks at some of the information available through /proc before detailing ps and vmstat. I/O Utilization is the next section where iostat is discussed along with another look at sar. Finally, Network Utilization rounds out this chapter with brief discussion of commands such as arp, ifconfig, and other basic network commands before detailing netstat. Throughout this chapter examples of output are given for many commands.
The authors do a great job at not only condensing the material but, more importantly, they also bring some highly technical concepts down to the reader's level. Take for example chapter 2, "Kernel Overview" where a detailed discussion of the architecture of the Linux kernel is given.
Part III of the book is devoted to system tuning (it's aptly titled "System Tuning"). This section of the book provides detailed background information so that the administrator can make educated decisions about what to tune. For example, chapter 9 is devoted to the Linux virtual memory subsystem and includes a discussion of not only how virtual memory is handled in the kernel (including new features for the 2.6 series) but also the tunable parameters for virtual memory.
Within Part III are chapters on the aforementioned virtual memory subsystem, the scheduler, I/O subsystems, file systems, network, IPC, and code tuning. Chapter 11, "File System Tuning", opens with a discussion of the basic terms in file systems before continuing on with discussion of specific file systems including ext2, ext3, ReiserFS, JFS, and XFS.
Part IV of the book looks at characteristics of Linux server applications. Doing so helps to frame the discussion of the different attributes important to tuning the server for each of these applications. The last section of the book, beginning of page 405, is devoted to case studies.
One final highlight for the book is that most chapters include a detailed references section with pointers to relevant information for that chapter. Some chapters have more references than others. The references might be anything from a man page to a magazine article to a book and a few other resources.
The combination of both detailed background information along with practical techniques, all of which are explained clearly, makes Performance Tuning for Linux Servers a great resource for Linux administrators who want to squeeze optimal performance from their server. I believe the book has a good shelf life that will keep it on my bookshelf for quite a long time.
You can purchase Performance Tuning for Linux Servers from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
In my experience, the number one tip for linux performance tuning is "man elvtune". I've seen it work miracles.
IIRC, she [Sandra Johnson] is the head of one of IBM's Linux Technology Centers. It was pretty interesting and I got to skim the book for a while. Looked good, but I always have the fear that books like this get outdated fast. It had half a page on top -- I told her to include htop in the next edition. No plug is as shameless as when you do it in person. ;)
The filesystem is the package manager
...is a pretty savvy fellow; he's a frequent LKML poster and has gotten some mentions on Kernel Traffic.
The Army reading list
It's worth it, for the better network performance
On the contrary ! Tuning fish can be accomplished by setting parameters in your $HOME/.ssh/config file.