alexgartrell

11 ms·

61.
by alexgartrell 7y ago
Yeah there are a remarkable set of container runtime tasks (package downloads, rootfs creation and management, etc) that are way easier with btrfs. It wasn’t always smooth sailing but luckily Chris, Josef, Omar and others are awesome and no
62.
by alexgartrell 7y ago
(At Facebook, not Google) when the technical writing is used to influence a technical outcome. Particularly a strategic one. a well written memo can change the way business is done and there’s not much ambiguity around where the idea came f
63.
by alexgartrell 7y ago
It's also been my experience as an engineering manager that it's best to think of yourself as a manager without authority.
64.
by alexgartrell 7y ago
If you can change libc then you have equal to or greater permissions than the calling process. So this strengthens the security model.
65.
by alexgartrell 7y ago
I went to high school with Logan and with Mario. Mario was in my AP Comp Sci class with Mrs. White. I remember being proud of my forays into encryption, concurrency, and network programming. And then I looked over and Mario had implemented
66.
by alexgartrell 7y ago
I don't work at AWS (and haven't) but I do work in the world of big infra and my wild-ass guess is that the user stuff in AWS doesn't run as consistently hot as the SaaS stuff that Amazon runs itself.
67.
by alexgartrell 7y ago
Short answer: no, same thing Original bpf is a much simpler bytecode. Ebpf extended it and made it essentially x86_64 assembly (semantically). Then we all decided to call ebpf bpf for reasons.
68.
by alexgartrell 7y ago
Not every memory access to a memory mapped file is automatically paged out immediately, so depending on vm dirty bytes, etc, you may get away with it for a while. But the worst case will be dismal and not unlikely.
69.
by alexgartrell 7y ago
Beyond implementation, how do you prove that a new statistic is correct and meaningful? Especially when it’s going to become part of the ABI forever? In this case, beyond the patches, we built oomd and ran the whole contraption in productio
70.
by alexgartrell 7y ago
First, there's no need to do this "on demand." You can ship a .o around and load it with bpftool. My team does a version of this at Facebook (using libbpf directly) and it works really well. The big use case for on-demand pro
71.
by alexgartrell 7y ago
I don't think people realize that SAT scores are a lot more arbitrary than they look. If you're one of the lucky kids whose parents set them up with reasonable coaching (and academic expectations in general), you do much better. I
72.
by alexgartrell 7y ago
I would love to hear the report’s take on what happened. The “and I still love her” epilogue makes me think that she probably has a pretty different take.
73.
by alexgartrell 7y ago
FWIW, Google certainly led on cgroup development for a while, but the cgroupv2 maintainer works at Facebook, and we're active in upstream container development in both linux and systemd. I don't necessarily think you're wrong
74.
by alexgartrell 8y ago
I recommend bpftrace as an entry point to working with bpf https://github.com/iovisor/bpftrace
75.
by alexgartrell 8y ago
I'm actually fairly certain it was "within working hours" free time. Facebook doesn't have 20% time or anything like that, but, in practice, there's lots of extra time for whatever you want. This was my experience a
76.
by alexgartrell 9y ago
Wasabi could compile VBScript, which was the language they had at the time. It's actually a more or less identical approach to the one Facebook took with Hack, but Facebook had a lot more resource to make it awesome.
77.
by alexgartrell 9y ago
I actually had an internship at Fog Creek in 2010. Ted Unangst (mentioned in the article) was my mentor. One thing I noticed about the folks there were that they were all crazy fucking smart. Joel had built this amazing recruiting machine t
78.
by alexgartrell 9y ago
ScopeGuards as imagined here (Facebook's folly library has one) are near-essential for writing reasonable systems code in C++. int fd = socket(...); if (fd < 0) return false; SCOPE_EXIT { ::close(fd); }; if (ioctl(fd,
79.
by alexgartrell 9y ago
You're kind of right. You can also use something like jump consistent hash [0] which only requires you to have a consistent ordering of the hosts where you're sending the information. We (Facebook) use something similar for our ca
80.
by alexgartrell 10y ago
One thing we do is have ICs interview leadership/management candidates. This is a piece of signal we're always looking for.
81.
by alexgartrell 10y ago
I think you're absolutely right, in general, but I've been at Facebook for 5 years now, and the one thing I'll say about it is that once you establish a track record of 1) doing good work and 2) making good long-term decision
82.
by alexgartrell 11y ago
Also in the hundreds of interviews club for Facebook and I also do not care about ++ or standard library memorization stuff. I think the recruiter is just trying to do as much as he/she can for you, because our recruiters are inherent
83.
by alexgartrell 11y ago
> You're forgetting something: the toll it takes on you as a person. > Those long nights, What nerd hasn't spent all night building something cool? I've /never/ been asked to stay at the office after hours an
84.
by alexgartrell 11y ago
I totally disagree. I've done a lot of operational and low-level systems work and handling obscure OOM scenarios is /really/, /really/ hard, and not at all worth the engineering effort. But, even assuming you handl
85.
by alexgartrell 11y ago
Jason Scott (creator of this documentary) is fantastic. I highly recommend all of his talks on YouTube. He also did the defcon documentary which was pretty good.
86.
by alexgartrell 11y ago
> One important thing to keep in mind when load-testing is that there are only so many socket connections you can have in Linux. This is a hard-coded kernel limitation, known as the Ephemeral Ports Issue. You can extend it (to some exten
87.
by alexgartrell 12y ago
This should be at the top.
88.
by alexgartrell 12y ago
It depends how you set up the forwarding. Casually looking at strings /usr/sbin/sshd on my devserver reveals that there is a mode to create a tun device, which sets up a more traditional VPN-ish thing (basically, your compute
89.
by alexgartrell 12y ago
Aw shucks. Mcrouter was the first piece of software I worked on at facebook. It's nice to see that you like it! (Though the only thing that lives on from me is the umbrella protocol)
90.
by alexgartrell 12y ago
That's what TAO (mentioned in the article) is for

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