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(Disclosure: I work at Joyent.) Are you accusing Brendan of misrepresenting SystemTap on slide 93? If so, could you be specific as to what that misrepresentat

(Disclosure: I work at Joyent.) Are you accusing Brendan of misrepresenting SystemTap on slide 93? If so, could you be specific as to what that misrepresentation is? Brendan has a ton of experience earnestly using SystemTap (or rather, trying to use it), and it's hard to see how sharing that experience makes either Brendan or his employer "look stupid." For more details on Brendan's explorations of SystemTap: http://dtrace.org/blogs/brendan/2011/10/15/using-systemtap/ That's several years old at this point, but the architectural limitations highlighted by Brendan haven't changed.

nailer 13y ago
Yes, I am accusing the author of deliberately misrepresenting facts. I'm not sure what's vague, let me recap: 1. 'might' implies the future. As you can tell from the post you're replying to, Systemtap is present thing. I think I actually put most of the tapsets shown on the Wikipedia page around 2009, and I was using them then. 2. Also, as the author partially acknowledges in the next slide, Ubuntu is the dumbest place to illustrate a typical Systemtap experience. I suspect that's deliberate, rather than ignorance as Sun tried that a few years back and I don't think anyone with any interest in the matter is ignorant enough not to remember the shitstorm. As I've written elsewhere: if your customers mostly run Ubuntu, then test dtrace on Ubuntu too. It'd give you just as accurate impression about what the dtrace 'experience' is as installing SystemTap on Ubuntu. Edit: actually looks like Joyent wrote the shitstorm post for a few years ago, you've still got it up, you still don't see anything wrong, and you just linked to it. christ read the HN comments from 2011. https://news.ycombinator.com/item?id=3118416 https://news.ycombinator.com/item?id=3118416 Edit 2: you're Bryan Cantrill. You didn't seem to care much about performance a while ago: http://cryptnet.net/mirrors/texts/kissedagirl.html http://cryptnet.net/mirrors/texts/kissedagirl.html Edit 3: more Cantrill classiness http://www.quora.com/Node-js/Why-did-Ben-Noordhuis-decide-to-leave-Node-js-development http://www.quora.com/Node-js/Why-did-Ben-Noordhuis-decide-to... Sorry to anyone who thinks I've gotten personal, but this guy is a well known... unsavoury character.
- brendangregg 13y ago
  Demonstrating on Ubuntu was indeed deliberate -- it's because most of my customers, and most of the performance issues I'm debugging, are on Ubuntu.
  - nailer 13y ago
    For the sake of consistency, then, I suggest you install dtrace on Ubuntu.
    - _delirium 13y ago
      I thought that was sort of his point, that you can't? I didn't read it as a DTrace vs. Systemtap discussion, but as an observability-on-SmartOS versus observability-on-Ubuntu discussion. If Ubuntu shipped with DTrace (or it could be easily installed), there'd be no real observability difference. It's a good point that this is a SmartOS vs. Ubuntu rather than SmartOS vs. all-Linuxes comparison, though.
      - nailer 13y ago
        Running dtrace on Ubuntu is possible: much like SystemTap, it's unsupported and involves lots of messing around. If someone wrote an article called 'Using dtrace' and wrote about the poor experience they had on Ubuntu it'd be just as (in)valid.
        brendangregg 13y ago
        Not really; DTrace has never been advertised as a tool for Linux. I've talked about the in-development ports, and that they aren't complete, and that they can panic/freeze systems. OTOH, SystemTap is advertised as tracing for Linux, and that it's safe for production use. My customers are running Linux, usually Ubuntu, and so I tried using SystemTap. I wouldn't have written that blog post if the SystemTap homepage simply said: "SystemTap is a tracing tool for RHEL. There are ports in progress for Ubuntu and others, which may panic or freeze systems." I disagree with the logic for not warning customers of this, and I think it's bad for Red Hat. If the homepage had stated that it's a RHEL tool, those frustrated users would have known to try RHEL, instead of giving up entirely.

nailer 13y ago

Yes, I am accusing the author of deliberately misrepresenting facts. I'm not sure what's vague, let me recap: 1. 'might' implies the future. As you can tell from the post you're replying to, Systemtap is present thing. I think I actually put most of the tapsets shown on the Wikipedia page around 2009, and I was using them then. 2. Also, as the author partially acknowledges in the next slide, Ubuntu is the dumbest place to illustrate a typical Systemtap experience. I suspect that's deliberate, rather than ignorance as Sun tried that a few years back and I don't think anyone with any interest in the matter is ignorant enough not to remember the shitstorm. As I've written elsewhere: if your customers mostly run Ubuntu, then test dtrace on Ubuntu too. It'd give you just as accurate impression about what the dtrace 'experience' is as installing SystemTap on Ubuntu. Edit: actually looks like Joyent wrote the shitstorm post for a few years ago, you've still got it up, you still don't see anything wrong, and you just linked to it. christ read the HN comments from 2011. https://news.ycombinator.com/item?id=3118416 https://news.ycombinator.com/item?id=3118416 Edit 2: you're Bryan Cantrill. You didn't seem to care much about performance a while ago: http://cryptnet.net/mirrors/texts/kissedagirl.html http://cryptnet.net/mirrors/texts/kissedagirl.html Edit 3: more Cantrill classiness http://www.quora.com/Node-js/Why-did-Ben-Noordhuis-decide-to-leave-Node-js-development http://www.quora.com/Node-js/Why-did-Ben-Noordhuis-decide-to... Sorry to anyone who thinks I've gotten personal, but this guy is a well known... unsavoury character.

brendangregg 13y ago
Demonstrating on Ubuntu was indeed deliberate -- it's because most of my customers, and most of the performance issues I'm debugging, are on Ubuntu.
- nailer 13y ago
  For the sake of consistency, then, I suggest you install dtrace on Ubuntu.
  - _delirium 13y ago
    I thought that was sort of his point, that you can't? I didn't read it as a DTrace vs. Systemtap discussion, but as an observability-on-SmartOS versus observability-on-Ubuntu discussion. If Ubuntu shipped with DTrace (or it could be easily installed), there'd be no real observability difference. It's a good point that this is a SmartOS vs. Ubuntu rather than SmartOS vs. all-Linuxes comparison, though.
    - nailer 13y ago
      Running dtrace on Ubuntu is possible: much like SystemTap, it's unsupported and involves lots of messing around. If someone wrote an article called 'Using dtrace' and wrote about the poor experience they had on Ubuntu it'd be just as (in)valid.
      - brendangregg 13y ago
        Not really; DTrace has never been advertised as a tool for Linux. I've talked about the in-development ports, and that they aren't complete, and that they can panic/freeze systems. OTOH, SystemTap is advertised as tracing for Linux, and that it's safe for production use. My customers are running Linux, usually Ubuntu, and so I tried using SystemTap. I wouldn't have written that blog post if the SystemTap homepage simply said: "SystemTap is a tracing tool for RHEL. There are ports in progress for Ubuntu and others, which may panic or freeze systems." I disagree with the logic for not warning customers of this, and I think it's bad for Red Hat. If the homepage had stated that it's a RHEL tool, those frustrated users would have known to try RHEL, instead of giving up entirely.