brancz

5 ms·

1.
by brancz 4mo ago
We write quite a bit of BPF at work for the Parca-Agent project[1]. And we find that even C is sometimes too high level of a language paired with modern optimization techniques as the code you write often doesn’t come out that way the other
2.
by brancz 4mo ago
It’s about density in a datacenter. With this you have 1PB in 4 drives, fitting in a 1u rack, which is just incredible. Also these drives don’t use regular SATA or SAS, they use PCIe, so these drives are also quite fast in comparison. Densi
3.
by brancz 5mo ago
I also find this misleading, and could be solved so easily by just explaining that of course varints need resolving and things will just happen lazily (presumably, I didn’t read the code) when they are requested to be read rather than eager
4.
Continuous Nvidia CUDA Profiling in Production(polarsignals.com)
98 points by brancz 11mo ago|10 comments
5.
by brancz 2y ago
Thank you! Overhead ultimately depends on the frequency, it defaults to 19hz per core, at which it’s less than 1%, which is tried and tested with all sorts of super heavy python, JVM, rust, etc. workloads. Since it’s per core it tends to be
6.
by brancz 2y ago
Already been done: 1) native unwinding: https://www.polarsignals.com/blog/posts/2022/11/29/dwarf-bas... 2) python: https://www.polarsignals.com/blog/posts/2023/10&#x2F
7.
by brancz 2y ago
We’re working hard to bring a lot of Strobelight to everyone through Parca[0] as OSS and Polar Signals[1] as the commercial version. Some parts already exists much to come this year! :) [0] https://www.parca.dev/ [1] https
8.
by brancz 2y ago
The point of the first one is that you can create snapshots from within the product where profiling data isn't forever. This is so you can use the pprof.me link in a GitHub issue, PR, or elsewhere and trust that the data never goes awa
9.
by brancz 2y ago
Keep an eye out on our blog we're working on some interesting things in this area!
10.
by brancz 2y ago
I mentioned this on another thread as well, but the point isn't that perf can't catch something like this, but it's that having continuous profiling set up makes it way easier to make profiling data an everyday part of your d
11.
by brancz 2y ago
Nobody is saying that a regular profiling tool can't detect it. However, it's one of those things that if you don't profile it regularly then these are easy things to miss. With a continuous profiler set up you skip everythin
12.
by brancz 2y ago
Prometheus gives you CPU/memory total metrics, the profiler used in the article gets you much higher resolution: down to the line number of your source code. If you're looking to optimize your project I would recommend using a pro
13.
by brancz 2y ago
Thank you for the feedback! Quickly worked with the S2 team to get the screenshot from the change added (it's just enabling the hardware acceleration feature in the sha2 crate)!
14.
by brancz 2y ago
I'm familiar with the paper, but it doesn't improve the situation in terms of LBR availability on cloud providers, does it?
15.
by brancz 2y ago
If I'm understanding correctly, this is collecting LBR data through hardware support for PGO/AutoFDO, right?
16.
Cloudy Forecast: How Predictable Is Communication Latency in the Cloud?(arxiv.org)
1 points by brancz 2y ago|0 comments
17.
Kubezonnet: Monitor Cross-Zone Network Traffic in Kubernetes(polarsignals.com)
4 points by brancz 2y ago|0 comments
18.
Introducing S2(s2.dev)
372 points by brancz 2y ago|195 comments
19.
by brancz 2y ago
There isn’t, because the indented way to use Parca is to profile production and always-on. However, we wouldn’t be against adding a mode like this! FWIW both the server and the agent are single statically linked binaries so while it’s a bit
20.
by brancz 2y ago
Glad you liked it! Yeah, we worked with a customer who really needs this badly and has done some unspeakable things to get by until now.
21.
by brancz 2y ago
Thanks for submitting! We know HN has a sweet spot for LuaJIT, so we figured it would eventually end up here. Quick summary: this post dives into the gory details of how we implemented an eBPF based profiler for LuaJIT. Let us know if you h
22.
by brancz 2y ago
Thanks for posting! We missed this being submitted yesterday, so let us know if you have any questions, we'll be sure to watch this thread!
23.
by brancz 2y ago
There certainly are, but I’d recommend making the first priority to look for who is actually going to be your most valuable business partner, their location in my opinion doesn’t really play any role in it. And in my experience a VC with co
24.
by brancz 2y ago
Thank you!
25.
by brancz 2y ago
Having gone through this a couple of times, I'll say that all of this is true, but in practice, I find the actual founding process not very complicated with neo-banks that understand the founding process well. I just founded a new GmbH
26.
by brancz 2y ago
This seems interesting for bpf programs that have essentially no user-space interaction which isn’t true for any of the things it lists on the landing page. Pixie, Cilium, Parca, etc have complex interactions between userspace and the bpf p
27.
by brancz 3y ago
Great comment! Just want to add we are making good progress on the JVM unwinder!
28.
by brancz 3y ago
The way perf does it is slow, as the entire stack is copied into user-space and is then asynchronously unwound. This is solvable as Brendan calls out, we’ve created an eBPF-based profiler at Polar Signals, that essentially does what you sai
29.
by brancz 3y ago
Parca's user-space code is apache2 and the eBPF code is GPL.
30.
by brancz 3y ago
Just about anyone who works on a profiler for native binaries has to solve this eventually. We had to as well for our eBPF-based profiler: https://www.polarsignals.com/blog/posts/2022/11/29/dwarf-bas

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