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DTrace Toolkit

brendangregg.com

46 pointsDanielRibeiro11 comments

Yeah, most of his stuff is pretty great but always read them before making the assumption that they are right. It is very easy to think everything is perfect if the output seems reasonable. Take Java method calls, the scripts that track method calls don't take into consideration method overloading at all. For an example of what you need to do take a look at http://www.osdev.org/dtrace/hotspot_extras/j_calltime2.d

Thanks for fixing it, and sorry for the bug.

Your advice is good - and is the case for all observability tools. Bugs happen, even in older tools like vmstat(1), top(1), etc. I try to test every tool I use (including those I develop) with "known workloads", and make sure the numbers match, or understand why they don't.

An advantage of the DTrace-based tools is that they are usually short scripts that you can understand easily and also tweak. Don't like strace on Linux? That's non-trivial to understand and to then change yourself. Don't like dtruss on Mac OS X? It's a DTrace script you can make a copy of and edit (as people have done). dtruss originated from the DTraceToolkit...

Less of a bug and more of an underestimation on how out of control method overloading is in Java :)

Thanks for the great tools!

How is DTrace for Linux doing? The last time I checked it had way less options than Solaris one.

That's covered in Brendan's recent talk at SCaLE 11x, also currently on HN: http://news.ycombinator.com/item?id=5310719

Thanks for the pointer!

Maybe Oracle did us all a favor by effectively forcing the dtrace folks to work on Linux. :)

Actually, we DTrace folks left the company[1]; the people doing the DTrace port to Linux are solid engineers, but they're not from the Sun acquisition. For more details on them and on their perspective on the port, see Kris Van Hees's excellent presentation at dtrace.conf last year.[2]

[1] http://www.youtube.com/watch?v=-zRN7XLCRhc#t=44m16s

[2] http://www.youtube.com/watch?v=NElog3MvUC8

Just to get it out there, this appears to be the current development of DTrace for Linux: https://github.com/dtrace4linux/linux http://crtags.blogspot.com/

Oracle has also finished an official port, though they released it only for Oracle Linux.

Oracle hasn't finished it yet (https://forums.oracle.com/forums/thread.jspa?messageID=10882...). It would be great if they did.

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