John Brady's Weblog

Wednesday August 10, 2005

DTrace is great!

DTrace is really good. I'm sure most of you know that by now, so I'm not telling you anything new. But I was in an internal presentation on DTrace the other day, and I was just blown away by the ease with which the presenter created D scripts (the DTrace language) to find out what was happening on a system, and then drill down further.

Up to now I have always viewed Solaris Containers as the most useful feature of Solaris 10 i.e. the feature that you would benefit from the most, and would be the one that made you migrate to Solaris 10. But after this presentation I have changed my mind. DTrace gives you so much observability on what is happening on your system. And it does it immediately, non-intrusively (no need to recompile your application), in real time (meaning as it happens with no special set up), gives you as much detail as you want (including access to all arguments to functions and system calls), and is totally safe and always ready to use in Solaris 10.

Presuming that most application environments have some inefficiency or other in them, DTrace just opens up everything for you to find out where your bottlenecks are, and help identify the root causes of them. And you don't need the source code of any application to do this.

Want to see what is consuming up all the I/O on the system? Then write a small DTrace script to count the calls to the read and write system calls. In fact, also look at the size of each I/O too, and show the distribution and count the I/Os by process.

I know that this is all standard DTrace stuff, and that it has all been described many times in the DTrace documentation and other articles and blogs. So I won't waste time trying to describe what DTrace is capable of. I just wanted to say, that if I was an administrator or developer I would be begging for Solaris 10, so that I could use DTrace to investigate any anomaly with the system.

Containers would take some time to do all the necessary work: design the final configuration, set it all up, migrate the applications over from other systems and environments into each container, and require monitoring to ensure that performance of each application was acceptable. But DTrace I could use immediately on Solaris 10, on all applications, regardless of their configuration and set up.

( Aug 10 2005, 10:57:55 AM BST ) Permalink Comments [0]