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Brendan's blog

Brendan Gregg's professional blog

Last Build Date: Fri, 13 May 2016 00:05:34 +0000


A New Challenge

Thu, 06 Mar 2014 00:44:05 +0000

About two years ago Joyent began offering Linux instances, running under KVM, stored on ZFS, and secured by Zones (“double hull virtualization”). Since then, I’ve been doing more and more work on Linux performance as customers deploy on these instances. It’s been fascinating to work on both the illumos and Linux kernels at the same [...]

Another 10 Performance Wins

Tue, 11 Feb 2014 18:08:39 +0000

Following on from my earlier 10 performance wins post, here is another group of 10 I have worked on. # Target Analyzed Key Tool Fixed Specific Improvement 11 redis System DTrace System scheduler 41% 12 rsync System DTrace Application app config 5x 13 mongoperf System DTrace System ZFS tuning up to 8x 14 backups System [...]

Benchmarking the Cloud

Fri, 10 Jan 2014 23:05:29 +0000

Benchmarking, and benchmarking the cloud, is incredibly error prone. I provided guidance though this minefield in the benchmarking chapter of my book (Systems Performance: Enterprise and the Cloud); that chapter can be read online on the InformIT site. I also gave a lightning talk about benchmarking gone wrong at Surge last year. In this post, [...]

Cloud Performance Training

Wed, 13 Nov 2013 22:36:41 +0000

Next week (Nov 18-22) I’m teaching a 5 day class on Cloud Performance, based on my book Systems Performance: Enterprise and the Cloud. I’ve taught this twice internally, and this will be the first class available publicly. I hope to teach it again, but one never knows, this may be the first and last chance [...]

Systems Performance: available now

Mon, 28 Oct 2013 22:57:21 +0000

My new book Systems Performance: Enterprise and the Cloud is shipping now from your favorite online book supplier (informIT, amazon). Thanks to those who have ordered a copy! I’ve already received feedback from people finding it useful, which is really gratifying. For an intro to the book, see my previous blog post about it. I’ve [...]

Open Source Systems Performance

Sun, 20 Oct 2013 19:17:25 +0000

There is an important and untold story about open source and systems performance, which I’m uniquely positioned to tell. I presented it at OSCON earlier this year, which was the perfect venue. My talk, Open Source Systems Performance, was a play in three acts: Act 1. Before Open Source Act 2. Open Source Act 3. [...]

The TSA Method

Fri, 11 Oct 2013 19:20:58 +0000

TSA Method in class (SmartOS) There are two basic performance analysis methodologies you can use for most performance issues. The first is the resource-oriented USE Method, which provides a checklist for identifying common bottlenecks and errors. The second is the thread-oriented TSA Method, for identifying issues causing poor thread performance. I summarized the TSA Method [...]

Control T for TENEX

Sat, 05 Oct 2013 16:26:00 +0000

I recently wrote about FreeBSD, and while on that OS I ran “sleep 5″ then hit Control-T: freebsd10$ sleep 5 load: 0.67 cmd: sleep 90628 [nanslp] 0.92r 0.00u 0.00s 0% 1464k sleep: about 4 second(s) left out of the original 5 Wow! This prints the “load:” and “sleep:” status lines, showing information about the process. [...]

The USE Method: Unix 7th Edition Performance Checklist

Sun, 29 Sep 2013 09:37:51 +0000

PDP 11/70 front panel (similar to the 11/45) Out of curiosity, I’ve developed a USE Method-based performance checklist for Unix 7th Edition on a PDP-11/45, which I’ve been running via a PDP simulator. 7th Edition is from 1979, and was the first Unix with iostat(1M) and pstat(1M), enabling more serious performance analysis from shipped tools. [...]

The USE Method: FreeBSD Performance Checklist

Wed, 25 Sep 2013 18:42:59 +0000

In this post, I’ll provide an example USE Method-based performance checklist for FreeBSD, for identifying common bottlenecks and errors. This is intended to be used early in a performance investigation, before moving onto more time consuming methodologies. This should be helpful for anyone using FreeBSD, especially system administrators. This was developed on FreeBSD 10.0 alpha, [...]