theojulienne

7 ms·

1.
by theojulienne 3mo ago
They were originally on their own datacenters + huge amounts of burst and ancillary stuff in AWS, the internal push to move away from "the competitor's cloud" after the acquisition was huge and entirely stupid. I'm ex-Gi
2.
by theojulienne 4mo ago
I think people spend way too much time trying to say that LLMs are bad / shouldn't be used / etc because the LLM can't get it right the first time and/or makes mistakes. I think this is because we all hope that soft
3.
by theojulienne 4mo ago
This. A ~staff software engineer designing big changes at one level above the raw implementation details using Opus 4.7 + superpowers today can genuinely ship multiple times more at the same quality level than pre-AI. The level of what a wh
4.
by theojulienne 5mo ago
I used to be a hubber - I really hope that institutional change happens at GitHub and I'm glad there are people there still fighting for it. I left because caring deeply (maybe, like the OP, too deeply) for the platform wasn't en
5.
by theojulienne 5mo ago
I can't speak to the last few years since I left, but over the many years I was there the git storage layer was almost never the core issue - it was well designed by infrastructure-minded nerds that leveraged and improved git and repli
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Ethernet MTU and TCP MSS: Why Connections Stall(theojulienne.io)
3 points by theojulienne 6y ago|0 comments
7.
by theojulienne 6y ago
Thanks for the suggestion! I did come across the `tcpsynbl.bt` script as I was writing up this post, but wanted to add the additional information around namespaces and report additional information, which didn't seem as trivial in `bpf
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Scaling Linux Services: Before accepting connections(theojulienne.io)
175 points by theojulienne 6y ago|29 comments
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Covid-19 in graphs: an open source site(covid.graphics)
10 points by theojulienne 6y ago|4 comments
10.
by theojulienne 7y ago
We didn't find any metric that surfaced zombie cgroups, presumably because the kernel mostly tries to hide them from user space since they have been deleted, but haven't been cleaned up. The only way we found at the time to track
11.
by theojulienne 7y ago
This insert_failed issue described in the video was one of the ones we discovered during investigations as well, but it was already well understood because of this excellent Xing blog post which was extremely useful and referenced internall
12.
by theojulienne 7y ago
This is actually interesting, we chose to use an overlay network because Kubernetes was a new, complex system that we initially didn't have experience with internally, and so we wanted to isolate problems it could create as much as pos
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by theojulienne 7y ago
The bcc script was run on the Kubernetes node itself directly over SSH, but it should be possible to run it in a privileged container as well.
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by theojulienne 7y ago
This is a great question, thank you for asking! Initially a few teams around the org had folks investigating poor performance from different perspectives of the applications that were observing issues. Once it was clear that it wasn’t the a
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by theojulienne 8y ago
Fastly's MAC-based solution to this was actually one of the existing implementations we read about back when designing the original implementation of GLB in 2015/16, along with Facebook's IPVS-based solution. We loved the ide
16.
by theojulienne 8y ago
We found that we could achieve 10G line rate with just the queues available to the VF, the NIC didn't seem to be a bottleneck providing DPDK was processing packets faster than line rate. It's worth noting that other traffic on the
17.
by theojulienne 9y ago
During some analysis we did notice that at least some cloud providers default to having instances with public IPs (with no network-level ACLs) by default, and some Linux distributions default to having memcached listening for UDP traffic an
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by theojulienne 10y ago
Since SYN packets only contain a limited set of information, if the SYN packets have spoofed source addresses then it is very difficult for a device in the destination network to filter/mitigate a SYN flood, since they look like legiti
19.
by theojulienne 10y ago
For the most part, since synsanity is a subset of SYNPROXY, the performance benchmarks from this SYNPROXY slide deck (and other documentations) are still relevant: http://people.netfilter.org/hawk/presentations/dev
20.
by theojulienne 10y ago
Great question! A large portion of our infrastructure still runs on Ubuntu Precise, and so the default "supported" options for the kernel on those machines are 3.2 or 3.13. Once you're on newer releases you get 4.x support, a