Dtrace

The problem On all current MacOS versions (Catalina 10.15.x, Big Sur 11.x) System Integrity Protection (SIP) is enabled by default and prevents most uses of dtrace and other tools and scripts based on it (i.e. dtruss). The usual way to make dtrace work on MacOS is to boot into recovery mode and…

bpftrace is an awesome tool that helps troubleshooting performance issues on production systems much easier. This short post summaries steps that I did to create a build for Centos 7. …

OK… Technically, it’s not “just” but last year… I’m just catching up on some things. Looking at the DTrace page on Oracle’s Open Source site, it seems that end of last year, Oracle finally removed all proprietary components to the DTrace framework and turned it all open source. …

When Apple announced their new file system, APFS, in June, I hustled to be in the front row of the WWDC presentation, questions with the presenters, and then the open Q&A session. I took a week to write up my notes which turned into as 12 page behemoth of a…

I had been procrastinating making the family holiday card. It was a combination of having a lot on my plate and dreading the formulation of our annual note recapping the year; there were some great moments, but I’m glad I don’t have to do 2016 again. It was just before…

It’s 4am and your test suite is taking 40 minutes, do you know what your gems are doing? Ask DTrace: Why are my tests so slow? | 8th Light Last time, we saw a few neat things DTrace can do, but now we're going to see a practical example of how it can…blog.8thlight.com

Using DTrace to figure out what calls cost — Due to heroic efforts by Steve Vinoski, Rickard Green, and Sverker Eriksson, we have an (experimental) so-called dirty-scheduler (DS) NIF API in the Erlang runtime, which has been somewhat stable since release 17.3. What is a NIF? It is a Natively-Implemented-Function, which is a shorthand for replacing Erlang code with…

I had been trying for a long time emulate a WAN on our test setup, to do impact analysis for few of our applications. Finally I got it running today on our solaris boxes. It essentially involves simple steps: Configure a router between two test systems. Set up routing for…