brendangregg

13 ms·

1. 31.▲
   by brendangregg 3y ago

   If I call the same "get statistics" command over and over in a loop (with zero queries), or 100% the same invalid query (to test the error path performance), I believe we'd call that a micro-benchmark, despite involving a ful
2. 32.▲
   by brendangregg 3y ago

   Thanks!
3. 33.▲
   by brendangregg 3y ago

   From the docs: "pgbench is a simple program for running benchmark tests on PostgreSQL. It runs the same sequence of SQL commands over and over" While it might call itself a benchmark, it behaves very microbenchmark-y. The other nu
4. 34.▲
   by brendangregg 3y ago

   Ah right, thanks, I remember I saw Andrii's analysis in the other thread. https://pagure.io/fesco/issue/2817#comment-826636
5. 35.▲
   by brendangregg 3y ago

   Those are microbenchmarks.
6. 36.▲
   by brendangregg 3y ago

   Thanks; what was the Python fix?
7. 37.▲
   by brendangregg 3y ago

   I don't know where 1-2% comes from, but for many scale production workloads I studied it was so close to 0% that it was tough to measure beyond noise on the cloud. That's not to say that 1-2% is wrong, but that it's likely so
8. 38.▲
   by brendangregg 4y ago

   I've had a few CO2 meters, and learned not to trust any <$100 as they don't really work. I look for meters that use non-dispersive infrared diffusion sensors (NDIRs), like the Aranet4. I've found the TIM10 desktop model fr
9. 39.▲
   by brendangregg 4y ago

   Why not dvorak one-handed (both right and left)? I've tried it when I've injured one hand badly, and it's optimized for one-handed typing.
10. 40.▲
    by brendangregg 4y ago

    Random cockatoo/FAANG story: I had an all-hands meeting earlier this year at Netflix, with me remote in Sydney, and a cockatoo knocked on my glass office door wanting to be let in -- so I'm saying "stop it! stop it!" whe
11. 41.▲
    by brendangregg 4y ago

    FWIW I did a "making of" video soon after, in 2009: https://www.youtube.com/watch?v=lMPozJFC8g0 . Only bit I missed discussing there was that I did try to download freeware frequency generators wondering if there
12. 42.▲
    by brendangregg 4y ago

    Yes, a Sun Microsystems training room in Sydney. The entire building is now gone. I was teaching sysadmin and performance classes there in the early 2000s, for both internal and external staff.
13. 43.▲
    by brendangregg 4y ago

    Thanks, I forgot where that one was.
14. 44.▲
    by brendangregg 4y ago

    Thanks! We have to work through each capability carefully. Some won't be safe, and will be available on bare-metal instances only. That may be ok, as it fits with the following evolution of an application (this is something I did for s
15. 45.▲
    by brendangregg 4y ago

    Yes, getting PMCs enabled in VMs was just the start, I think the next hardware capabilities to enable are: - PEBS (Precise/Processor event based sampling, so that we can accurately get instruction pointers on PMC events) - uncore
16. 46.▲
    by brendangregg 4y ago

    Thanks, good to see a new perf tool (and not just another procfs top clone :-). I've started using processor trace in the cloud, thanks to bare-metal instances, but for years I couldn't touch it (not available in VMs). There'
17. 47.▲
    by brendangregg 5y ago

    Ah right, people have asked about that before. I'm just happy with a single normal-sized monitor. Maybe related, but we once went around the Netflix parking lot with Blippar to look at the KBB value of the cars, and found that I was dr
18. 48.▲
    by brendangregg 5y ago

    I understand why people might think that, but I'm not sure it'd be great for the culture for me to be different from my coworkers. We're all working on important things, and we all need to collaborate together.
19. 49.▲
    by brendangregg 5y ago

    Yes, I helped organize the Netflix cricket practice sessions. Netflix has a cricket team (in engineering) that in the past has played in the GPL: Google Premiership League, along with several other tech companies. Lots of fun! We practiced
20. 50.▲
    by brendangregg 5y ago

    A number of times people have asked about my desk over the years, and I'm curious as to why! I've visited other tech companies in the bay area, and the desks I see (including for 7-figure salary engineers) are the same as everyone
21. 51.▲
    by brendangregg 5y ago

    I've been clear on HN multiple times that I saw no future in the Solaris/SmartOS ecosystem by 2014, which is one (but not the only) reason I left it. I was right too: https://www.itjobswatch.co.uk/jobs/uk&#x2F
22. 52.▲
    by brendangregg 5y ago

    I touch it now and then; search for "BSD" on https://www.brendangregg.com . Netflix has hired more great BSD folk, so I haven't needed to do a lot on it for a while. I do enjoy it though, and it's usually much
23. 53.▲
    by brendangregg 5y ago

    Just a note: books, magazines, slide decks (and more*) aren't getting any wider. As time goes on, and code and command output gets wider, it's getting a bit harder to write educational materials. I have slide decks and books that
24. 54.▲
    by brendangregg 5y ago

    We use bpftrace to feed GUIs at Netflix (json output was added so that it can be incorporated in GUIs). You can come up with situations where bcc is better, but you should really make that clear in the article so as to not mislead beginners
25. 55.▲
    by brendangregg 5y ago

    People learning to code observability tools in eBPF should be starting with bpftrace, and the tutorials should too. I've made this point in blog posts and keynotes etc. Doing it using bcc is how we did it 6 years ago -- it's out o
26. 56.▲
    by brendangregg 5y ago

    Thanks for your comment. Yes, it's a bummer to see people waste time reinventing something, and, to then have multiple solutions to the same problem. It's clutter, and wastes end user's time to sort through. One solution is t
27. 57.▲
    by brendangregg 5y ago

    bcc comes with the sslsniff(8) tool that does just this, created by Adrian Lopez in 2016. I don't know why the article didn't mention that, since they are using bcc. It's also a trivial bpftrace program, which we've been
28. 58.▲
    by brendangregg 5y ago

    For anyone thinking of using fingerprints: There's a number of people, especially some older women (due to a lifetime of hand washing dishes) and chemotherapy survivors, who no longer have legible fingerprints. Insisting all users auth
29. 59.▲
    by brendangregg 5y ago

    Systems Performance 1st edition sold over 10k copies for the English edition, and that was half Solaris when it was falling in market share. 2nd edition is more Linux focused, and shows how eBPF fits into the toolset, so I'd assume it&
30. 60.▲
    by brendangregg 5y ago

    Most issues we hit are solved by the monitoring GUIs (Atlas, FlameCommander, PerfDash, S3 log collection, etc.), but some aren't, and there's a ton more information available from the CLI tools. Imagine losing your five nines beca