3 ms·

Dtrace isn't completely dead; it's used to great effect as the underlying technology behind Instruments (performance analyzer/visualizer) on OSX. It never has

Dtrace isn't completely dead; it's used to great effect as the underlying technology behind Instruments (performance analyzer/visualizer) on OSX. It never has really managed to catch on as a standalone tool by itself, though. Part of that's the licensing situation on Linux, but I'd hypothesize that part of it is also that it's a pretty complicated tool to use, interpret, and act on-- you don't hear a lot about SystemTap (same concept, GPLed for Linux-friendliness) these days, either.

seliopou 11y ago
I'd push back on the 'complicated' part. The dtrace language is heavily based on awk, which every modern *NIX ships with, and that every software engineer and sysadmin have at least a passing familiarity with. The main difference between the two is whereas awk is meant to operate over a stream of semi-structured lines, dtrace operates over a stream of probe firings. The high-level structures of the scripts, though, are the same: /pattern/ { statements } In a awk, when a line matches a the patter, the corresponding statements fire. In dtrace, when a probe matches a pattern, the corresponding statements fire. Integers, strings, arrays, and all those other sorts of features of the language are the same (though there are some special functions introduced by dtrace to help you collect and visualize aggregations). So from a language perspective, if you know awk, you mostly know dtrace. All that's left to do is learn the pattern language. If you want to do that effectively, you have to know not just the syntax of the patterns, but useful probes to listen for, and useful ways to use the information that's gleaned. This involves knowing things about operating systems. Most software engineers don't know much about operating systems so they think the tool is stupid.

3 ms·

Dtrace isn't completely dead; it's used to great effect as the underlying technology behind Instruments (performance analyzer/visualizer) on OSX. It never has

by JonathonW 11y ago

seliopou 11y ago
I'd push back on the 'complicated' part. The dtrace language is heavily based on awk, which every modern *NIX ships with, and that every software engineer and sysadmin have at least a passing familiarity with. The main difference between the two is whereas awk is meant to operate over a stream of semi-structured lines, dtrace operates over a stream of probe firings. The high-level structures of the scripts, though, are the same: /pattern/ { statements } In a awk, when a line matches a the patter, the corresponding statements fire. In dtrace, when a probe matches a pattern, the corresponding statements fire. Integers, strings, arrays, and all those other sorts of features of the language are the same (though there are some special functions introduced by dtrace to help you collect and visualize aggregations). So from a language perspective, if you know awk, you mostly know dtrace. All that's left to do is learn the pattern language. If you want to do that effectively, you have to know not just the syntax of the patterns, but useful probes to listen for, and useful ways to use the information that's gleaned. This involves knowing things about operating systems. Most software engineers don't know much about operating systems so they think the tool is stupid.