Language Selection

English French German Italian Portuguese Spanish

Android Leftovers

More in Tux Machines

today's leftovers

  • Learn more about distributed databases with ShardingSphere

    Apache ShardingSphere is an open source distributed database, plus an ecosystem users and developers need for their database to provide a customized and cloud-native experience. In the three years since it joined the Apache Foundation, the ShardingSphere core team has worked hard with the community to create an open source, robust, and distributed database and a supporting ecosystem. ShardingSphere doesn't quite fit into the usual industry mold of a simple distributed database middleware solution. ShardingSphere recreates the distributed pluggable system, enabling actual user implementation scenarios to thrive and contributing valuable solutions to the community and the database industry.

  • AWS DocumentDB not MongoDB-compatible, says MongoDB Inc
  • Winners in the Month of LibreOffice, November 2021!

    At the start of November, we revved up a new Month of LibreOffice, celebrating community contributions all across the project. We do these every six months – so how many people got sticker packs this time? Check it out…

Programming Leftovers

  • Cracking the Spotify Code

    Spotify offers a little picture that, when scanned, opens almost anything searchable with Spotify. Several lines are centered on the Spotify logo with eight different heights, storing information in octal. Many visual encoding schemes encode some URI (Uniform Resource Identifier) that provides a unique identifier for that specific song, album, or artist when decoded. Since many URIs on Spotify are pretty long (one example being spotify :show:3NRV0mhZa8xeRT0EyLPaIp which clocks in at 218 bits), some mechanism is needed to compress the URIs down to something more manageable. Enter the media reference, a short sequence encoding a specific URI, generally under 40 bits. The reference is just a lookup in a database that Spotify maintains, so it requires a network connection to resolve. The actual encoding scheme from media reference to the values in the bars is quite complex involving CRC, convolution, and puncturing. The CRC allows the program to check for correct decoding, and the convolution enables the program to have a small number of read errors while still having an accurate result. Puncturing is just removing bits to reduce the numbers encoded, relying on convolution to fill in the holes.

  • Day 7: Neural Nets in Raku (Part 1) – Raku Advent Calendar

    Thinky the Elf was sitting in his office, it had been a closet but he’d been given it as his office after the great baked beans incident. It wasn’t his fault. He was right that feeding the reindeer beans would give them a jet boost but Santa had not been all that happy about it. And his tendency to stare of into space while suddenly having a thought wasn’t great while working on the shop floor meant it was safer to put him out of the way to do some thinking. Recently he’d been thinking about how to sort children into naughty or nice. This was Santa’s big job all year and Thinky thought that there must be a way to simplify it, he’d spent some time watching videos on YouTube and there was one that gave a brilliant description of Neural Networks (jump to 20 minutes for that bit but it’s an interesting video). As Thinky watched this he couldn’t help thinking about Raku and how the connections between nodes felt like Supplies.

  • Rblpapi 0.3.12: Fixes and Updates

    The Rblp team is happy to announce a new version 0.3.12 of Rblpapi which just arrived at CRAN. Rblpapi provides a direct interface between R and the Bloomberg Terminal via the C++ API provided by Bloomberg (but note that a valid Bloomberg license and installation is required). This is the twelveth release since the package first appeared on CRAN in 2016. Changes are detailed below and include both extensions to functionality, actual bug fixes and changes to the package setup. Special thanks goes to Michael Kerber, Yihui Xie and Kai Lin for contributing pull requests!

  • LLVM Now Has "Official" Support For Targeting NEC's Vector Engine (VE) - Phoronix

    The LLVM compiler infrastructure supports not only a growing number of CPU architectures but continues to lead when it comes to its support for different accelerators. Back in 2019 NEC was working to upstream their SX-Aurora VE "Vector Engine" Accelerator and now as of this week that target is considered officially supported upstream. NEC originally launched the SX-Aurora Vector Engine (VE) back in 2018 as a PCI Express accelerator card and supporting up to eight vector processors per server. The NEC SX-Aurora has its own architecture for the "VE" and is backed by HBM2 memory. The current VE processor is rated for 1.53 TB/s of memory bandwidth and a double precision peak performance of 3.07 TFLOPS or 4.91 single precision TFLOPS.

  • 5 Excellent Free Books to Learn CSS - LinuxLinks

    Web pages are built with HTML, which specifies the content of a page. CSS (Cascading Style Sheets) is a separate language which specifies a page’s appearance. CSS code is made of static rules. Each rule takes one or more selectors and gives specific values to a number of visual properties. Those properties are then applied to the page elements indicated by the selectors. Here’s our recommended books to learn CSS.

SSH Key Rotation with the POSIX Shell - Sunset Nears for Elderly Keys

OpenBSD has recently stressed to us the value of key rotation by their use of “Signify” distribution release signatures. We have realized that SSH keys should also rotate, to reduce the risk of powerful keys that fall into the wrong hands which become “the gift that keeps on giving.” There have always been open questions on the retirement of SSH keys. These questions have grown in volume and many are joining the advocacy for SSH certificate authorities. To “rotate” an SSH key is to replace it, in such a way that it is no longer recognized, requiring removal from the authorized_keys file. SSH rotation is commonly addressed with Ansible, but this leaves many users on smaller systems or lacking privilege without recourse. A more basic and accessible method to migrate SSH keys is sorely lacking. Below is presented an SSH key rotation script written in nothing more than the POSIX shell. There is palpable danger in the misuse of such a tool. Many administrators control inaccessible systems that entail massive inconvenience in a loss of control. Demonstrated here are rotation schemes of increasing risk, for any holder of a key to choose, to their own tolerance. Hopefully, I have not made grave mistakes in the design. The most conservative users of this approach should tread with extreme caution, test carefully, and ensure alternate means of access prior to any deployment. As the author, I have no desire to assume any responsibility for a failed rotation, and its consequences. I especially disavow the “wipe” option below to remove entries from authorized_keys. It is presented as commentary, not working code. In any case, we foolishly rush in where the more prudent fear to tread. Read more

Amazon Linux 2022 Performs Well, But Intel's Clear Linux Continues Leading In The Cloud

AWS recently introduced Amazon Linux 2022 in preview form as the latest iteration of their Linux distribution now based on Fedora with various alterations to catering to their customers running it on EC2. Last week were benchmarks looking at Amazon Linux 2022 compared to Amazon Linux 2 and other distributions like CentOS and Ubuntu. In this article we are seeing how Amazon Linux 2022 can compete with Intel's own Clear Linux performance-optimized distribution. Read more