kdkeyser

6 ms·

1.
by kdkeyser 4y ago
What kind of consistency guarantees does this offer?
2.
by kdkeyser 5y ago
Did you consider using an B-epsilon-tree [1] ? This is a B-tree, but each node has a staging area for new writes. In practice, incoming writes get added to the staging area of the root node, and once a staging area is full, it gets propagat
3.
by kdkeyser 5y ago
Any background info/links to this? The Wyze forum comes up empty, only some discussions on WebRTC being complex to add.
4.
by kdkeyser 5y ago
This would be interesting to integrate into https://github.com/openmiko/openmiko which is a firmware for the T20 based ip-cameras. Right now, I am not aware of any cheap ip camera that can stream its H264 video to a re
5.
by kdkeyser 6y ago
Haxl is actually an example of "the more impressive and more useful" approach: it is an abstraction embedded within a Haskell library, that allows you to express your "intent" in simple, standard Haskell code, decoupled
6.
by kdkeyser 6y ago
This indeed seems to be the main/only point of criticism in this post that is valid: however, it is not that Haskell has no "pragmatic" libraries to get stuff done (e.g. WAI/Warp, Yesod, Servant, ... are top notch, pract
7.
by kdkeyser 6y ago
The issue is that it hasn't translated into local production fabs. Which means that the semiconductor ecosystems in Belgium is still really small. IMEC's research mainly benefits companies like Intel, Samsung, TSMC. The only relat
8.
by kdkeyser 6y ago
ReScript (formerly called ReasonML), is an interesting option for web apps (especially the front-end part), if you are interested in Ocaml-like languages. Language-wise, it is Ocaml with a different syntax layer, so all of the nice things a
9.
by kdkeyser 6y ago
I second this. I dislike the liberal usage of metaprogramming, especially in the context of a code base that you have to work on with multiple people. It adds another layer of concepts/complexity/magic that everyone in the team ha
10.
by kdkeyser 6y ago
In your example, there is no relation between anything in Module1Interface and Module2Interface. Probably closer would be (not sure if this is possible in Typescript): class CustomModule<S, T1 extends Module1Interface<S>, T2
11.
by kdkeyser 6y ago
I don't see how you come to that conclusion. Assigning a name to a requirement (~ an interface) is the most simple usage of the module. E.g. to define something like IComparable, you could write: module type Comparable = sig ty
12.
by kdkeyser 6y ago
For me, the value of a module is that you can describe a set of multiple types and the functions that operate on these types, all in one place. In OO, there is essentially one type that is "special", the type of the class you defi
13.
by kdkeyser 6y ago
Glass platters have been used a lot since the IBM "Deathstar" series. They are used in almost all 2.5 inch laptop drives.
14.
by kdkeyser 6y ago
I am not sure that my message was completely clear: my point was that despite Go having an objectively old/primitive type system, compared to modern state of the art, that does not preclude it from being a successful "production&q
15.
by kdkeyser 6y ago
I think what you witnessed is the fact that being an expert in programming language theory or category theory, does not make you a good software engineer. Haskell is surprisingly well suited for back-end services (e.g REST). Warp (an HTTP
16.
by kdkeyser 6y ago
I fail to see how else than "primitive" you can call the Go type system: it is roughly what you would get from a language designed in the 70's, and a lot of advances have since been made. Whether or not these advances make a
17.
by kdkeyser 6y ago
I have not yet seen a storage system that is actually 100% S3 compatible. Either functionality is missing, and/or there are corner cases where the behavior is just slightly different. It is also a complicated API, that often looks like
18.
by kdkeyser 6y ago
My experience with using general purpose languages for things like configuration or build systems has not been great. You always seem to end up with building a bunch of abstractions on top of that language, which culminates in another in-ho
19.
by kdkeyser 6y ago
I worked at a startup (Amplidata) where we build a distributed storage system in OCaml. It got acquired by Western Digital, which later sold it to Quantum. Afaik, there is still development going on using OCaml. Couple of things I took away
20.
by kdkeyser 6y ago
MIPS is still alive in the IP camera world. There exist very cheap SoC's (e.g. the Ingenic T20 - http://www.ingenic.com.cn/en/?product/id/14.html ), tailored towards making cheap network camera's (~
21.
by kdkeyser 6y ago
I hacked together a proof of concept of using Janus to wrap the H264 RTSP stream of the Xiaomi Dafang into a WebRTC stream without transcoding, giving close to real-time streaming of the ip camera to browsers without needing a plug-in. Curr
22.
by kdkeyser 7y ago
They have been doing erasure coding since at least 2016 (it is mentioned in their original Magic Pocket post), just like almost all distributed storage system, so nothing really new there. This article is about single-region storage vs. mul
23.
by kdkeyser 7y ago
The Dropbox technical blog is always a very interesting read, I love that they provide so much detail into the technical background of their solution. Still was left with quite some questions when trying to understand this article though: -
24.
by kdkeyser 7y ago
Does Backblaze have any SMR drives in use, or do you have plans to start using them? Would be really interesting to see if these exhibit a worse failure rate. Anyway, thanks for sharing this data, I really like the openness.
25.
by kdkeyser 8y ago
CRUSH is an example (and not the first) of a "distributed rebuild" approach: you have an array of N drives (with N large, e.g. 100), and if 1 drive fails, you read in parallel from all (N-1) remaining drives, while distributing th
26.
by kdkeyser 8y ago
A full blown filesystem is overkill for an object store. You could use something like libzbc ( https://github.com/hgst/libzbc ) to write directly to the SMR drives on the block level. I believe Ceph now has abstracted
27.
by kdkeyser 8y ago
If you are the target audience for these drives, you likely don't even consider regular (i.e. including random) IO as a use-case for modern HDD's . 10+ TB HDD's really only make sense for sequential IO, even if they technical
28.
by kdkeyser 8y ago
There is also Intel's ISA-L: https://github.com/01org/isa-l It contains optimized Galois Field multiplication, resulting in Reed Solomon (both Vandermonde as well as Cauchy) at multiple GB/s on a modern x86 C
29.
by kdkeyser 9y ago
I believe TokuDB is using a flavor of B epsilon trees, i.e. a B tree with, per node, an associated staging area for writes to that node or its child nodes. Keeps inserts localised at the top of the tree, until the staging areas fill up. The
30.
by kdkeyser 9y ago
For an n+k Reed Solomon code, you can recover from k erasures, but only from k/2 errors.

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