https://pinboard.in/u:jm/public/ recent bookmarks from jm 2026-05-19T09:06:52+00:00 https://oldhome.schmorp.de/marc/bournegol.html jm via:fanf bournegol algol programming languages bizarre funny unix bin-sh macros https://pinboard.in/ https://pinboard.in/u:jm/b:a88b5cc3a90c/ 2025-08-25T16:20:35+00:00 https://lobste.rs/s/gvtlpo/email_is_easy_email_address_quiz#c_vkssdf jm email history 1970s via:fanf smtp ietf standards internet https://pinboard.in/ https://pinboard.in/u:jm/b:219e04c983b2/ 2025-05-19T09:03:07+00:00 https://mcyoung.xyz/2023/03/29/rseq-checkout/ jm via:fanf linux concurrency multiprocessing rseq cpu-local https://pinboard.in/ https://pinboard.in/u:jm/b:d8ecd0840341/ 2025-03-25T10:21:11+00:00 https://arxiv.org/abs/2308.16862 jmSince its invention HyperLogLog has become the standard algorithm for approximate distinct counting. Due to its space efficiency and suitability for distributed systems, it is widely used and also implemented in numerous databases. This work presents UltraLogLog, which shares the same practical properties as HyperLogLog. It is commutative, idempotent, mergeable, and has a fast guaranteed constant-time insert operation. At the same time, it requires 28% less space to encode the same amount of distinct count information, which can be extracted using the maximum likelihood method. Alternatively, a simpler and faster estimator is proposed, which still achieves a space reduction of 24%, but at an estimation speed comparable to that of HyperLogLog. In a non-distributed setting where martingale estimation can be used, UltraLogLog is able to reduce space by 17%. Moreover, its smaller entropy and its 8-bit registers lead to better compaction when using standard compression algorithms. All this is verified by experimental results that are in perfect agreement with the theoretical analysis which also outlines potential for even more space-efficient data structures. A production-ready Java implementation of UltraLogLog has been released as part of the open-source Hash4j library. (via Tony Finch)]]> via:fanf algorithms data-structures hyperloglog ultraloglog counting count-distinct distinct approximation counts java https://pinboard.in/ https://pinboard.in/u:jm/b:a54e7c3c0b7d/ 2025-02-27T17:26:52+00:00 https://poweruser.blog/using-dtrace-with-sip-enabled-3826a352e64b jm macos mac debugging osx via:fanf dtrace tracing sip https://pinboard.in/ https://pinboard.in/u:jm/b:e887bd86dfe8/ 2025-01-28T11:42:07+00:00 https://emschwartz.me/understanding-the-bm25-full-text-search-algorithm/ jm via:fanf lucene elasticsearch search text algorithms sqlite full-text bm25 https://pinboard.in/ https://pinboard.in/u:jm/b:d86bae9bc5f1/ 2024-12-17T14:43:43+00:00 https://dhashe.com/how-to-build-highly-debuggable-c-binaries.html jm via:fanf gdb c++ coding debugging builds https://pinboard.in/ https://pinboard.in/u:jm/b:ab5c9fb90833/ 2024-09-13T12:08:48+00:00 https://dougallj.wordpress.com/2022/08/20/faster-zlib-deflate-decompression-on-the-apple-m1-and-x86/ jm via:fanf compression deflate optimization assembly c optimisation hacks https://pinboard.in/ https://pinboard.in/u:jm/b:e410c595df19/ 2024-08-21T15:05:20+00:00 https://drossbucket.com/2021/06/30/hacker-news-folk-wisdom-on-visual-programming/ jm gui hn no-code programming tools coding visual-programming hacker-news via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:fb154ee1f0dd/ 2024-03-28T18:13:00+00:00 https://engineering.fb.com/2021/07/09/data-infrastructure/ribbon-filter/ jmBuilding on some prior lines of research, the Ribbon filter combines a simplified, faster, and more flexible construction algorithm; a data layout optimized for filter queries; and near-continuous configurability to make a practical alternative to static (immutable) Bloom filters. While well-engineered Bloom filters are extremely fast, they use roughly 50 percent more space (overhead) than the information-theoretic lower bound for filters on arbitrary keys. When Bloom filters cannot meet an application’s space efficiency targets, Ribbon filter variants dominate in space-versus-time trade-offs with near continuous configurability and space overhead as low as 1 percent or less. Ribbon filters have O(1) query times and save roughly 1/3 of memory compared with Bloom filters. At Facebook’s scale, we expect Ribbon filters to save several percent of RAM resources, with a tiny increase in CPU usage for some major storage systems. However, we do not implement efficiency gains at all engineering costs, so it’s also important to have a user-friendly data structure. This issue stalled implementation of other Bloom alternatives offering some space savings. The Ribbon filter opens these new trade-offs without introducing notable discontinuities or hazards in the configuration space. In other words, there is some complexity to make Ribbon filters general and highly configurable, but these details can be hidden behind a relatively simple API. You have essentially free choice over any three of the four core performance dimensions — number of keys added to the set, memory usage, CPU efficiency, and accuracy — and the accuracy is automatically well optimized. (via Tony Finch)]]> via:fanf algorithms facebook programming ribbon-filters data-structures bloom-filters set-membership papers https://pinboard.in/ https://pinboard.in/u:jm/b:9391321eb119/ 2022-07-26T11:19:24+00:00 https://dotat.at/@/2022-07-15-histogram.html jm c c++ histograms storage data-structures via:fanf hg64 https://pinboard.in/ https://pinboard.in/u:jm/b:22d0c9f27fa1/ 2020-12-03T11:43:32+00:00 https://www.hammerspoon.org/ jm via:fanf automation osx mac lua scripting hammerspoon https://pinboard.in/ https://pinboard.in/u:jm/b:2eb669dd1863/ 2020-07-30T22:05:19+00:00 https://www.dremio.com/apache-arrow-explained/ jmArrow combines the benefits of columnar data structures with in-memory computing. It provides the performance benefits of these modern techniques while also providing the flexibility of complex data and dynamic schemas. And it does all of this in an open source and standardized way. (via Tony Finch)]]> via:fanf arrow data formats compression columnar-storage storage libraries https://pinboard.in/ https://pinboard.in/u:jm/b:fa06288fd165/ 2020-01-07T15:08:10+00:00 https://eprint.iacr.org/2020/014 jm Abstract: The SHA-1 hash function was designed in 1995 and has been widely used during two decades. A theoretical collision attack was first proposed in 2004 [WYY05], but due to its high complexity it was only implemented in practice in 2017, using a large GPU cluster [SBK+17]. More recently, an almost practical chosen-prefix collision attack against SHA-1 has been proposed [LP19]. This more powerful attack allows to build colliding messages with two arbitrary prefixes, which is much more threatening for real protocols. In this paper, we report the first practical implementation of this attack, and its impact on real-world security with a PGP/GnuPG impersonation attack. We managed to significantly reduce the complexity of collisions attack against SHA-1: on an Nvidia GTX 970, identical-prefix collisions can now be computed with a complexity of 261.2261.2 rather than 264.7264.7, and chosen-prefix collisions with a complexity of 263.4263.4 rather than 267.1267.1. When renting cheap GPUs, this translates to a cost of 11k US\$ for a collision, and 45k US\$ for a chosen-prefix collision, within the means of academic researchers. Our actual attack required two months of computations using 900 Nvidia GTX 1060 GPUs (we paid 75k US\$ because GPU prices were higher, and we wasted some time preparing the attack). Therefore, the same attacks that have been practical on MD5 since 2009 are now practical on SHA-1. In particular, chosen-prefix collisions can break signature schemes and handshake security in secure channel protocols (TLS, SSH). We strongly advise to remove SHA-1 from those type of applications as soon as possible. We exemplify our cryptanalysis by creating a pair of PGP/GnuPG keys with different identities, but colliding SHA-1 certificates. A SHA-1 certification of the first key can therefore be transferred to the second key, leading to a forgery. This proves that SHA-1 signatures now offers virtually no security in practice. The legacy branch of GnuPG still uses SHA-1 by default for identity certifications, but after notifying the authors, the modern branch now rejects SHA-1 signatures (the issue is tracked as CVE-2019-14855). (Via Tony Finch)]]> via:fanf security sha sha-1 crypto hashes hashing pgp gpg collisions https://pinboard.in/ https://pinboard.in/u:jm/b:468127bda2ca/ 2019-11-03T22:43:03+00:00 https://www.hardill.me.uk/wordpress/2019/11/02/pi4-usb-c-gadget/ jm via:fanf usb dev raspberry-pi hardware usb-c gadgets https://pinboard.in/ https://pinboard.in/u:jm/b:9f7f777d743d/ 2019-02-18T11:05:52+00:00 https://arxiv.org/abs/1902.04023 jm java go python open-source quantiles percentiles approximation statistics sketching algorithms via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:6c84ec8a0947/ 2019-02-13T10:50:12+00:00 https://blog.scottlogic.com/2019/01/31/the-curious-case-of-disappeared-buses.html jmSo what have we learned? One thing we are sure is that data of different qualities – genuinely real-time, pseudo real-time (Type 2 and Type 1), and non-real-time (scheduled) data – all present in the data stream. Among these the most interesting are Type 2 pseudo real-time data. They appear to be the root cause of the phenomenon of disappearing buses. Type 2 pseudo-real-time data are not totally bogus. One possible explanation of their existence can be this. The bus company has limited but not full tracking information on some of their buses. For example, it may know the location of a bus only when the bus leaves the bus terminal. Instead of not showing any data at all about the bus, the bus company uses interpolation to predict the locations of the bus, and reports these as if those are real-time data. ]]> via:fanf bristol buses public-transport rtpi estimation open-data https://pinboard.in/ https://pinboard.in/u:jm/b:955f9d3a4d4b/ 2019-02-07T09:31:08+00:00 https://blog.benjojo.co.uk/post/eve-online-bgp-internet jm via:fanf bgp networking internet routing london-underground trains https://pinboard.in/ https://pinboard.in/u:jm/b:c84d01a61942/ 2018-10-03T10:57:19+00:00 http://www.doxsey.net/blog/kubernetes--the-surprisingly-affordable-platform-for-personal-projects jmAt the beginning of the year I spent several months deep diving on Kubernetes for a project at work. As an all-inclusive, batteries-included technology for infrastructure management, Kubernetes solves many of the problems you're bound to run into at scale. However popular wisdom would suggest that Kubernetes is an overly complex piece of technology only really suitable for very large clusters of machines; that it carries a large operational burden and that therefore using it for anything less than dozens of machines is overkill. I think that's probably wrong. Kubernetes makes sense for small projects and you can have your own Kubernetes cluster today for as little as $5 a month. (via Tony Finch)]]> via:fanf deployment howto kubernetes ops projects hacks clustering https://pinboard.in/ https://pinboard.in/u:jm/b:fa2e19a6200f/ 2018-02-19T11:01:41+00:00 https://l0rd.github.io/containerspatterns/#1 jm docker containers design-patterns coding packaging deployment via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:0e99583f73a7/ 2018-01-12T13:43:51+00:00 https://github.com/google/highwayhash jm 64 bits and therefore infeasible to reverse. Permuting equalizes the distribution of the resulting bytes. The internal state occupies four 256-bit AVX2 registers. Due to limitations of the instruction set, the registers are partitioned into two 512-bit halves that remain independent until the reduce phase. The algorithm outputs 64 bit digests or up to 256 bits at no extra cost. In addition to high throughput, the algorithm is designed for low finalization cost. The result is more than twice as fast as SipTreeHash. We also provide an SSE4.1 version (80% as fast for large inputs and 95% as fast for short inputs), an implementation for VSX on POWER and a portable version (10% as fast). A third-party ARM implementation is referenced below. Statistical analyses and preliminary cryptanalysis are given in https://arxiv.org/abs/1612.06257.' (via Tony Finch)]]> siphash highwayhash via:fanf hashing hashes algorithms mac google hash https://pinboard.in/ https://pinboard.in/u:jm/b:c96748eca1a7/ 2017-10-09T10:27:09+00:00 http://nullprogram.com/blog/2017/10/06/ jmThis week I took a crack at writing a branchless UTF-8 decoder: a function that decodes a single UTF-8 code point from a byte stream without any if statements, loops, short-circuit operators, or other sorts of conditional jumps. [...] Why branchless? Because high performance CPUs are pipelined. That is, a single instruction is executed over a series of stages, and many instructions are executed in overlapping time intervals, each at a different stage. Neat hack (via Tony Finch)]]> algorithms optimization unicode utf8 branchless coding c via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:e6a102583433/ 2017-09-19T13:29:15+00:00 http://www.itv.com/news/central/2017-09-18/undercover-operation-to-catch-drivers-too-close-to-cyclists-praised/ jm An initiative to protect cyclists from dangerous overtaking has been praised, after reducing the amount of cyclists killed or seriously injured on the roads by 20% over the last year. Operation 'Close Pass' was devised by West Midlands Police as a low cost way of preventing accidents caused by motorists who are driving too close for comfort. (Via Tony Finch)]]> cycling via:fanf safety overtaking roads bikes https://pinboard.in/ https://pinboard.in/u:jm/b:ef55426809be/ 2017-08-12T08:50:41+00:00 https://01.org/hyperscan jma high-performance multiple regex matching library. It follows the regular expression syntax of the commonly-used libpcre library, yet functions as a standalone library with its own API written in C. Hyperscan uses hybrid automata techniques to allow simultaneous matching of large numbers (up to tens of thousands) of regular expressions, as well as matching of regular expressions across streams of data. Hyperscan is typically used in a DPI library stack. Hyperscan began in 2008, and evolved from a commercial closed-source product 2009-2015. First developed at Sensory Networks Incorporated, and later acquired and released as open source software by Intel in October 2015.  Hyperscan is under a 3-clause BSD license. We welcome outside contributors. This is really impressive -- state of the art in parallel regexp matching has improved quite a lot since I was last looking at it. (via Tony Finch)]]> via:fanf regexps regular-expressions text matching pattern-matching intel open-source bsd c dpi scanning sensory-networks https://pinboard.in/ https://pinboard.in/u:jm/b:eb7f772d7923/ 2017-07-24T13:39:27+00:00 https://news.ycombinator.com/item?id=14691212 jm"Solidity/EVM is by far the worst programming environment I have ever encountered. It would be impossible to write even toy programs correctly in this language, yet it is literally called "Solidity" and used to program a financial system that manages hundreds of millions of dollars." Via Tony Finch ]]> blockchain ethereum programming coding via:fanf funny fail floating-point money json languages bugs reliability https://pinboard.in/ https://pinboard.in/u:jm/b:ca02abcc222e/ 2017-07-13T20:06:17+00:00 https://utcc.utoronto.ca/~cks/space/blog/sysadmin/UnderstandingIODNSIssue jmUsing data from glue records instead of looking things up yourself is common but not mandatory, and there are various reasons why a resolver would not do so. Some recursive DNS servers will deliberately try to check glue record information as a security measure; for example, Unbound has the harden-referral-path option (via Tony Finch). Since the original article reported seeing real .io DNS queries being directed to Bryant's DNS server, we know that a decent number of clients were not using the root zone glue records. Probably a lot more clients were still using the glue records, through. (via Tony Finch)]]> via:fanf dns security dot-io cctlds glue-records delegation https://pinboard.in/ https://pinboard.in/u:jm/b:79776642bf4f/ 2017-05-31T13:42:11+00:00 http://up2v.nl/2017/05/29/what-went-wrong-in-british-airways-datacenter/ jmMinutes later power was restored was resumed in what one source described as “uncontrolled fashion.” Instead of gradual restore, all power was restored at once resulting in a power surge.   BA CEO Cruz told BBC Radio this power surge  caused network hardware to fail. Also server hardware was damaged because of the power surge. It seems as if the UPS was the single point of failure for power feed of the IT equipment in Boadicea House . The Times is reporting that the same UPS was powering both Heathrow based datacenters. Which could be a double single point of failure if true (I doubt it is) The broken network  stopped the exchange of messages between different BA systems and application. Without messaging, there is no exchange of information between various applications. BA is using Progress Software’s Sonic [enterprise service bus]. (via Tony Finch)]]> postmortems ba airlines outages fail via:fanf datacenters ups power progress esb j2ee https://pinboard.in/ https://pinboard.in/u:jm/b:4624716d7fe5/ 2017-03-06T14:20:20+00:00 https://mackeeper.com/blog/post/339-spammergate-the-fall-of-an-empire jmIn that screenshot, a RCM co-conspirator describes a technique in which the spammer seeks to open as many connections as possible between themselves and a Gmail server. This is done by purposefully configuring your own machine to send response packets extremely slowly, and in a fragmented manner, while constantly requesting more connections. Then, when the Gmail server is almost ready to give up and drop all connections, the spammer suddenly sends as many emails as possible through the pile of connection tunnels. The receiving side is then overwhelmed with data and will quickly block the sender, but not before processing a large load of emails. (via Tony Finch) ]]> via:fanf spam antispam gmail blocklists packets tcp networking https://pinboard.in/ https://pinboard.in/u:jm/b:e5c526710904/ 2017-01-11T12:21:41+00:00 https://donatstudios.com/Falsehoods-Programmers-Believe-About-CSVs jmMuch of my professional work for the last 10+ years has revolved around handing, importing and exporting CSV files. CSV files are frustratingly misunderstood, abused, and most of all underspecified. While RFC4180 exists, it is far from definitive and goes largely ignored. Partially as a companion piece to my recent post about how CSV is an encoding nightmare, and partially an expression of frustration, I've decided to make a list of falsehoods programmers believe about CSVs. I recommend my previous post for a more in-depth coverage on the pains of CSVs encodings and how the default tooling (Excel) will ruin your day. (via Tony Finch)]]> via:fanf csv excel programming coding apis data encoding transfer falsehoods fail rfc4180 https://pinboard.in/ https://pinboard.in/u:jm/b:c8921999d6ab/ 2016-11-05T21:35:06+00:00 http://jeffe.cs.illinois.edu/teaching/algorithms/ jmThis page contains lecture notes and other course materials for various algorithms classes I have taught at the University of Illinois, Urbana-Champaign. The notes are numbered in the order I cover the material in a typical undergraduate class, wtih notes on more advanced material (indicated by the symbol ♥) interspersed appropriately. [...] In addition to the algorithms notes I have been maintaining since 1999, this page also contains new notes on "Models of Computation", which cover a small subset of the material normally taught in undergraduate courses in formal languages and automata. I wrote these notes for a new junior-level course on "Algorithms and Models of Computation" that Lenny Pitt and I developed, which is now required for all undergraduate computer science and computer engineering majors at UIUC. Via Tony Finch]]> via:fanf book cs algorithms jeff-erickson uiuc https://pinboard.in/ https://pinboard.in/u:jm/b:7b0e68a81a8e/ 2016-09-13T13:32:19+00:00 http://www.metzdowd.com/pipermail/cryptography/2016-September/030231.html jm crypto security rngs prngs random bridge cards via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:9f34e4e19524/ 2016-06-21T14:58:57+00:00 https://janheine.wordpress.com/2016/06/14/suspension-losses-confirmed/ jm cycling research bicycles via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:7be8ca6da584/ 2016-04-11T11:02:05+00:00 http://danluu.com/google-sre-book/ jm books reading devops ops google sre dan-luu via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:f27fece650a2/ 2016-03-16T12:13:00+00:00 https://tools.ietf.org/html/rfc7754 jmThe Internet is structured to be an open communications medium. This openness is one of the key underpinnings of Internet innovation, but it can also allow communications that may be viewed as undesirable by certain parties. Thus, as the Internet has grown, so have mechanisms to limit the extent and impact of abusive or objectionable communications. Recently, there has been an increasing emphasis on "blocking" and "filtering", the active prevention of such communications. This document examines several technical approaches to Internet blocking and filtering in terms of their alignment with the overall Internet architecture. When it is possible to do so, the approach to blocking and filtering that is most coherent with the Internet architecture is to inform endpoints about potentially undesirable services, so that the communicants can avoid engaging in abusive or objectionable communications. We observe that certain filtering and blocking approaches can cause unintended consequences to third parties, and we discuss the limits of efficacy of various approaches. (via Tony Finch)]]> via:fanf blocking censorship filtering internet rfcs rfc isps https://pinboard.in/ https://pinboard.in/u:jm/b:3b43dcc1f35e/ 2015-12-22T11:21:26+00:00 http://blog.cryptographyengineering.com/2015/12/on-juniper-backdoor.html jmFor the past several years, it appears that Juniper NetScreen devices have incorporated a potentially backdoored random number generator, based on the NSA's Dual_EC_DRBG algorithm. At some point in 2012, the NetScreen code was further subverted by some unknown party, so that the very same backdoor could be used to eavesdrop on NetScreen connections. While this alteration was not authorized by Juniper, it's important to note that the attacker made no major code changes to the encryption mechanism -- they only changed parameters. This means that the systems were potentially vulnerable to other parties, even beforehand. Worse, the nature of this vulnerability is particularly insidious and generally messed up. [....] The end result was a period in which someone -- maybe a foreign government -- was able to decrypt Juniper traffic in the U.S. and around the world. And all because Juniper had already paved the road. One of the most serious concerns we raise during [anti-law-enforcement-backdoor] meetings is the possibility that encryption backdoors could be subverted. Specifically, that a back door intended for law enforcement could somehow become a backdoor for people who we don't trust to read our messages. Normally when we talk about this, we're concerned about failures in storage of things like escrow keys. What this Juniper vulnerability illustrates is that the danger is much broader and more serious than that. The problem with cryptographic backdoors is not that they're the only way that an attacker can break intro our cryptographic systems. It's merely that they're one of the best. They take care of the hard work, the laying of plumbing and electrical wiring, so attackers can simply walk in and change the drapes. (via Tony Finch)]]> via:fanf crypto backdoors politics juniper dual-ec-drbg netscreen vpn https://pinboard.in/ https://pinboard.in/u:jm/b:934dcb1b02c0/ 2015-10-21T14:33:51+00:00 https://github.com/01org/hyperscan jma high-performance multiple regex matching library. Hyperscan uses hybrid automata techniques to allow simultaneous matching of large numbers (up to tens of thousands) of regular expressions and for the matching of regular expressions across streams of data. Via Tony Finch]]> via:fanf regexps regex dpi hyperscan dfa nfa hybrid-automata text-matching matching text strings streams https://pinboard.in/ https://pinboard.in/u:jm/b:f41962a90f1b/ 2015-10-09T12:39:09+00:00 http://arstechnica.com/tech-policy/2015/10/gene-patents-probably-dead-worldwide-following-australian-court-decision/ jmThe court based its reasoning on the fact that, although an isolated gene such as BRCA1 was "a product of human action, it was the existence of the information stored in the relevant sequences that was an essential element of the invention as claimed." Since the information stored in the DNA as a sequence of nucleotides was a product of nature, it did not require human action to bring it into existence, and therefore could not be patented. Via Tony Finch.]]> via:fanf australia genetics law ipr medicine ip patents https://pinboard.in/ https://pinboard.in/u:jm/b:46c25adbed67/ 2015-10-06T13:04:46+00:00 http://fanf.livejournal.com/137283.html jm crit-bit popcount bits bitmaps tries data-structures via:fanf qp-tries crit-bit-tries hacks memory https://pinboard.in/ https://pinboard.in/u:jm/b:3f98dd35e7f6/ 2015-06-22T09:52:04+00:00 https://github.com/chrissimpkins/codeface jm via:fanf fonts coding ui https://pinboard.in/ https://pinboard.in/u:jm/b:797718ef12c4/ 2015-06-10T15:07:42+00:00 http://blog.silentsignal.eu/2015/06/10/poisonous-md5-wolves-among-the-sheep/ jm md5 hashing antivirus malware security via:fanf bugs https://pinboard.in/ https://pinboard.in/u:jm/b:11ef4e54eeb8/ 2015-06-02T13:55:04+00:00 http://developerblog.redhat.com/2015/06/01/five-different-ways-handle-leap-seconds-ntp/ jmWith ntpd, the kernel backward step is used by default. With ntpd versions before 4.2.6, or 4.2.6 and later patched for this bug, the -x option (added to /etc/sysconfig/ntpd) can be used to disable the kernel leap second correction and ignore the leap second as far as the local clock is concerned. The one-second error gained after the leap second will be measured and corrected later by slewing in normal operation using NTP servers which already corrected their local clocks. It's all pretty messy though :(]]> ntpd ntp chronyd clocks time synchronization via:fanf linux leap-seconds https://pinboard.in/ https://pinboard.in/u:jm/b:52c79bcfcdf0/ 2015-01-13T23:54:42+00:00 http://arstechnica.com/apple/2015/01/why-dns-in-os-x-10-10-is-broken-and-what-you-can-do-to-fix-it/ jm via:fanf dns osx mac mdnsresponder discoveryd bugs https://pinboard.in/ https://pinboard.in/u:jm/b:1674c7e6af03/ 2014-12-28T23:20:32+00:00 http://www.cs.utexas.edu/users/mckinley/papers/uncertainty-asplos-2014.pdf jm, a new programming language abstraction for uncertain data. We implement a Bayesian network semantics for computation and conditionals that improves program correctness. The runtime uses sampling and hypothesis tests to evaluate computation and conditionals lazily and efficiently. We illustrate with sensor and machine learning applications that Uncertain improves expressiveness and accuracy.' (via Tony Finch)]]> uncertainty estimation types strong-typing coding probability statistics machine-learning sampling via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:4e691997eba0/ 2014-12-21T23:16:25+00:00 https://pmf.silvrback.com/fixing-tethering-on-android-kitkat jmGoogle made a change in Android 4.4 which allows operators to know when users are using tethering and conveniently block tethered devices from accessing internet. This can be fixed permanently using the following procedure. Well this is stupid. (via Tony Finch) ]]> via:fanf tethering android mobile https://pinboard.in/ https://pinboard.in/u:jm/b:82ceba235b40/ 2014-12-09T22:36:38+00:00 https://wiki.gnome.org/Projects/OSTree jm"git for operating system binaries". OSTree is a tool for managing bootable, immutable, versioned filesystem trees. It is not a package system; nor is it a tool for managing full disk images. Instead, it sits between those levels, offering a blend of the advantages (and disadvantages) of both. You can use any build system you like to place content into it on a build server, then export an OSTree repository via static HTTP. On each client system, "ostree admin upgrade" can incrementally replicate that content, creating a new root for the next reboot. This provides fully atomic upgrades. Any changes made to /etc are propagated forwards, and all local state in /var is shared. A key goal of the project is to complement existing package systems like RPM and Debian packages, and help further their evolution. In particular for example, RPM-OSTree (linked below) has as a goal a hybrid tree/package model, where you replicate a base tree via OSTree, and then add packages on top. ]]> os gnome git linux immutable deployment packaging via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:7fcc1fbae602/ 2014-11-06T12:16:08+00:00 http://arstechnica.com/business/2012/04/coolest-jobs-in-tech-literally-running-a-south-pole-data-center/ jm via:fanf antarctica datacenters icecube wipac south-pole cold ops https://pinboard.in/ https://pinboard.in/u:jm/b:22361fb623b7/ 2014-10-06T15:23:44+00:00 https://wiki.recompile.se/wiki/Mandos jm via:fanf mandos encryption security server ops sysadmin linux https://pinboard.in/ https://pinboard.in/u:jm/b:4723bcd4e08c/ 2014-09-08T09:04:50+00:00 https://mailinabox.email/ jm via:fanf mail diy hosting webmail ops https://pinboard.in/ https://pinboard.in/u:jm/b:3ab3b1c8c5de/ 2014-09-01T22:26:39+00:00 http://0pointer.net/blog/revisiting-how-we-put-together-linux-systems.html jmInstantiating a new system or OS container (which is exactly the same in this scheme) just consists of creating a new appropriately named root sub-volume. Completely naturally you can share one vendor OS copy in one specific version with a multitude of container instances. Everything is double-buffered (or actually, n-fold-buffered), because usr, runtime, framework, app sub-volumes can exist in multiple versions. Of course, by default the execution logic should always pick the newest release of each sub-volume, but it is up to the user keep multiple versions around, and possibly execute older versions, if he desires to do so. In fact, like on ChromeOS this could even be handled automatically: if a system fails to boot with a newer snapshot, the boot loader can automatically revert back to an older version of the OS. (via Tony Finch)]]> via:fanf linux docker btrfs filesystems unionfs copy-on-write os hacking unix https://pinboard.in/ https://pinboard.in/u:jm/b:b9563993a8c5/ 2014-09-01T09:02:26+00:00 https://github.com/facebook/folly/blob/master/folly/docs/FBVector.md jm c++ facebook performance algorithms vectors via:fanf optimization https://pinboard.in/ https://pinboard.in/u:jm/b:4903013d2867/ 2014-08-26T22:42:52+00:00 http://googleprojectzero.blogspot.co.uk/2014/08/the-poisoned-nul-byte-2014-edition.html jm via:fanf buffer-overflows security nul byte exploits google project-zero https://pinboard.in/ https://pinboard.in/u:jm/b:bfa7b40cbea2/ 2014-07-03T09:27:04+00:00 https://network23.org/blackoutaustria/2014/07/01/to-whom-it-may-concern-english-version/ jm austria tor security law liability internet tunnelling eu via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:2f1ac37c3780/ 2014-06-18T15:48:28+00:00 http://csl.stanford.edu/~christos/publications/2014.pegasus.isca.pdf jm pegasus power-management power via:fanf google latency scaling https://pinboard.in/ https://pinboard.in/u:jm/b:ddece9bbccdf/ 2014-06-18T13:58:55+00:00 https://gist.github.com/lelandbatey/8677901 jm This [shell one-liner] will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.: convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2" Some kind soul has put up a quickie web UI here: http://api.o2b.ru/whiteboardcleaner]]> graphics tools whiteboard imagemagick text images cleanup gimp photoshop via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:91d687763ace/ 2014-05-07T12:53:52+00:00 https://code.facebook.com/posts/220956754772273/an-analysis-of-facebook-photo-caching/ jm via:fanf caching facebook architecture photos images cache fifo lru scalability https://pinboard.in/ https://pinboard.in/u:jm/b:3b5a7ad7f689/ 2014-04-15T09:50:40+00:00 http://lekkertech.net/akamai.txt jm via:fanf cryptography openssl heartbleed akamai security ssl tls https://pinboard.in/ https://pinboard.in/u:jm/b:2e435fd4c303/ 2014-04-15T09:47:38+00:00 https://blogs.kent.ac.uk/unseenit/2013/10/18/stalled-scp-and-hanging-tcp-connections/ jmIt looks like there’s a firewall in the middle that’s doing additional TCP sequence randomisation which was a good thing, but has been fixed in all current operating systems. Unfortunately, it seems that firewall doesn’t understand TCP SACK, which when coupled with a small amount of packet loss and a stateful host firewall that blocks invalid packets results in TCP connections that stall randomly. A little digging revealed that firewall to be the Cisco Firewall Services Module on our Canterbury network border. (via Tony Finch)]]> via:fanf cisco networking firewalls scp tcp hangs sack tcpdump https://pinboard.in/ https://pinboard.in/u:jm/b:4774b16849b8/ 2014-02-05T16:40:10+00:00 https://www.simonsfoundation.org/quanta/20140130-perfecting-the-art-of-sensible-nonsense/ jm obfuscation cryptography via:fanf security hard-lattice-problem crypto science https://pinboard.in/ https://pinboard.in/u:jm/b:fee9ea88b6c5/ 2014-01-27T13:53:50+00:00 http://www.thinkbroadband.com/news/6261-sky-parental-controls-break-jquery-website.html jmSky still appears to be blocking code.jquery.com and all files served via the site, and more worryingly is that if you try to report the incorrect category, once signing in on the Sky website you an error page. We suspect the site was blocked due to being linked to by a properly malicious website, i.e. code.jquery.com and some javascript files were being used on a dodgy website and every domain mentioned was subsequently added to a block list. (via Tony Finch) ]]> via:fanf sky filtering internet uk anti-phishing phish jquery javascript http web fps false-positives https://pinboard.in/ https://pinboard.in/u:jm/b:583339fa52bd/ 2014-01-21T23:24:58+00:00 http://blog.backblaze.com/2014/01/21/what-hard-drive-should-i-buy/ jmBecause Backblaze has a history of openness, many readers expected more details in my previous posts. They asked what drive models work best and which last the longest. Given our experience with over 25,000 drives, they asked which ones are good enough that we would buy them again. In this post, I’ll answer those questions. ]]> backblaze backup hardware hdds storage disks ops via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:33f2b7ef62aa/ 2013-10-21T16:32:15+00:00 http://sigops.org/sosp/sosp13/papers/p33-david.pdf jm synchronization scalability cpus hardware papers via:fanf multicore cas https://pinboard.in/ https://pinboard.in/u:jm/b:f3c2f37df2b0/ 2013-10-14T09:45:54+00:00 http://aphyr.com/posts/299-the-trouble-with-timestamps jmTimestamps, as implemented in Riak, Cassandra, et al, are fundamentally unsafe ordering constructs. In order to guarantee consistency you, the user, must ensure locally monotonic and, to some extent, globally monotonic clocks. This is a hard problem, and NTP does not solve it for you. When wall clocks are not properly coupled to the operations in the system, causal constraints can be violated. To ensure safety properties hold all the time, rather than probabilistically, you need logical clocks. ]]> clocks time distributed databases distcomp ntp via:fanf aphyr vector-clocks last-write-wins lww cassandra riak https://pinboard.in/ https://pinboard.in/u:jm/b:dcc3c0071909/ 2013-09-15T22:36:52+00:00 http://utcc.utoronto.ca/~cks/space/blog/web/SSLWebComplexity jm security ssl tls packaging via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:46c3fc4c515e/ 2013-08-21T22:29:36+00:00 http://blog.docker.io/2013/08/containers-docker-how-secure-are-they/ jm via:fanf security containerization docker containers lxc linux ops https://pinboard.in/ https://pinboard.in/u:jm/b:8247118ad5ff/ 2013-06-09T21:45:05+00:00 http://www.komar.org/faq/colorado-cataract-surgery-crystalens/ultra-violet-color-glow/ jmI've been very happy so far with the Crystalens implant for Cataract Surgery [...] one unexpected/interesting aspect is I see a violet glow that others do not - perhaps I'm more sensitive to the low end of the visible light spectrum. (via Tony Finch)]]> via:fanf science perception augmentation uv light sight cool cataracts surgery lens eyes https://pinboard.in/ https://pinboard.in/u:jm/b:89077a5e8de2/ 2013-04-03T12:59:55+00:00 http://www.joelonsoftware.com/items/2013/04/02.html jmThe fastest growing industry in the US right now, even during this time of slow economic growth, is probably the patent troll protection racket industry. ]]> joel-on-software patents swpats shakedown extortion us-politics patent-trolls via:fanf https://pinboard.in/ https://pinboard.in/u:jm/b:ebf874da2acf/ 2013-03-19T23:20:54+00:00 https://github.com/armon/bloomd jma high-performance C server which is used to expose bloom filters and operations over them to networked clients. It uses a simple ASCII protocol which is human readable, and similar to memcached.(via Tony Finch) ]]> via:fanf memcached bloomd open-source bloom-filters https://pinboard.in/ https://pinboard.in/u:jm/b:058c62c7b990/ 2013-03-12T21:43:34+00:00 http://domainincite.com/12238-confusion-reigns-over-three-hijacked-cctlds jmWhat seems to be happening here is that [two companies involved] have had some kind of dispute, and that as a result the registrants and the reputation of three countries’ ccTLDs have been harmed. Very amateurish. ]]> tlds domains via:fanf amateur-hour dns cctlds registrars adamsnames https://pinboard.in/ https://pinboard.in/u:jm/b:53a73c2d5c01/ 2013-02-28T22:08:48+00:00 http://opinionator.blogs.nytimes.com/2013/02/27/its-the-sugar-folks/?smid=tw-share jmA study published in the Feb. 27 issue of the journal PLoS One links increased consumption of sugar with increased rates of diabetes by examining the data on sugar availability and the rate of diabetes in 175 countries over the past decade. And after accounting for many other factors, the researchers found that increased sugar in a population’s food supply was linked to higher diabetes rates independent of rates of obesity. In other words, according to this study, obesity doesn’t cause diabetes: sugar does. The study demonstrates this with the same level of confidence that linked cigarettes and lung cancer in the 1960s. As Rob Lustig, one of the study’s authors and a pediatric endocrinologist at the University of California, San Francisco, said to me, “You could not enact a real-world study that would be more conclusive than this one.” ]]> nytimes health food via:fanf sugar eating diabetes papers medicine https://pinboard.in/ https://pinboard.in/u:jm/b:699d3f912d4d/ 2013-02-28T10:00:48+00:00 http://translate.google.com/translate?sl=auto&hl=en&tl=en&u=http://izvestia.ru/news/545688 jm virus trojans malware via:fanf kaspersky https://pinboard.in/ https://pinboard.in/u:jm/b:428ea63f321e/