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Justin's Linklog Posts

Links for 2013-06-26

Published June 26, 2013

The easy way to find JMX metrics in the field using jmxsh

Published June 26, 2013

(oh look, a proper blog post!)

JMX is the de-facto standard in the Java and JVM-based world for exposing service metrics, and feeds nicely to tools like Graphite using JMXTrans and others. However, it’s pretty obtuse and over-complex, and it can be hard to figure out what path the JMX metrics will show up under once deployed.

Unfortunately, once a JVM-based service is deployed to EC2, it becomes very difficult to use jconsole to connect to it, due to deficiencies and crappy design in the JMX RMI protocol (I love the way they reinvented the broken parts of IIOP in that respect). Don’t even bother; instead, use jmxsh: https://code.google.com/p/jmxsh/ .

To use this, you need to modify the service process’ command line to include the following JVM args, so that the remote JMX API is exposed:

-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=16660 -Dcom.sun.management.jmxremote.local.only=true -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false

Change the port number if there is already a process running on that port. Ensure the port isn’t accessible from off-host; in EC2, this should be safe enough to use once that port number is not in the EC2 security group.

Go to https://code.google.com/p/jmxsh/downloads/list and download the latest jmxsh-FOO.jar; e.g. ‘wget https://jmxsh.googlecode.com/files/jmxsh-R5.jar’. Then on the host, as the UID the service is running under, run: ‘java -jar jmxsh-R5.jar -h 127.0.0.1 -p 16660’. You can then hit “Enter” to go into “Browse Mode”, and you’ll get text menus like this:

 ====================================================

  Attribute List:

        1. -r- long        MaxFileDescriptorCount
        2. -r- long        OpenFileDescriptorCount
        3. -r- long        CommittedVirtualMemorySize
        4. -r- long        FreePhysicalMemorySize
        5. -r- long        FreeSwapSpaceSize
        6. -r- long        ProcessCpuTime
        7. -r- long        TotalPhysicalMemorySize
        8. -r- long        TotalSwapSpaceSize
        9. -r- String      Name
       10. -r- int         AvailableProcessors
       11. -r- String      Arch
       12. -r- double      SystemLoadAverage
       13. -r- String      Version

   SERVER: service:jmx:rmi:///jndi/rmi://127.0.0.1:16660/jmxrmi
   DOMAIN: java.lang
   MBEAN:  java.lang:type=OperatingSystem

 ====================================================

Navigate through the MBean tree looking for good Attributes which would make good metrics (5 in the list above, for example). Note the MBean and the Attribute names.

Links for 2013-06-25

Published June 25, 2013

  • Liberty issues claim against British Intelligence Services over PRISM and Tempora privacy scandal

    James Welch, Legal Director for Liberty, said:   “Those demanding the Snoopers’ Charter seem to have been indulging in out-of-control snooping even without it – exploiting legal loopholes and help from Uncle Sam. “No-one suggests a completely unpoliced internet but those in power cannot swap targeted investigations for endless monitoring of the entire globe.”
    Go Liberty! Take note, ICCL, this is how a civil liberties group engages with internet issues.

    (tags: prism nsa gchq surveillance liberty civil-liberties internet snooping)

  • shades

    A command-line utility in Ruby to perform (a) OLAP cubing and (b) histogramming, given whitespace-delimited line data

    (tags: ruby olap number-crunching data histograms cli)

  • ‘If I was your cloud provider, I’d never let you down’

    This is the thing that’s put me off Joyent. They make claims like this one from October 2012:

    We’ve given our other partners 99.9999% uptime.
    This despite a 10-day outage of their BingoDisk and Strongspace storage services in January 2008, 1734 days previously (http://www.datacenterknowledge.com/archives/2008/01/21/joyent-services-back-after-8-day-outage/). If you assume that is the only outage they’ve had since then, that works out as 99.4% uptime. Quite a few less nines…

    (tags: joyent marketing uptime two-nines fail strongdisk)

  • js-hll

    Good UI for exploration of HyperLogLog set intersections and unions.

    One of the first things that we wanted to do with HyperLogLog when we first started playing with it was to support and expose it natively in the browser. The thought of allowing users to directly interact with these structures — perform arbitrary unions and intersections on effectively unbounded sets all on the client — was exhilarating to us. […] we are pleased to announce the open-source release of AK’s HyperLogLog implementation for JavaScript, js-hll. We are releasing this code under the Apache License, Version 2.0. We knew that we couldn’t just release a bunch of JavaScript code without allowing you to see it in action — that would be a crime. We passed a few ideas around and the one that kept bubbling to the top was a way to kill two birds with one stone. We wanted something that would showcase what you can do with HLL in the browser and give us a tool for explaining HLLs. It is typical for us to explain how HLL intersections work using a Venn diagram. You draw some overlapping circles with a border that represents the error and you talk about how if that border is close to or larger than the intersection then you can’t say much about the size of that intersection. This works just ok on a whiteboard but what you really want is to just build a visualization that allows you to select from some sets and see the overlap. Maybe even play with the precision a little bit to see how that changes the result. Well, we did just that!

    (tags: javascript ui hll hyperloglog algorithms sketching js sets intersection union apache open-source)

  • Sketch of the Day: K-Minimum Values

    Another sketching algorithm — this one supports set union and intersection operations more easily than HyperLogLog when there are more than 2 sets

    (tags: algorithms coding space-saving cardinality streams stream-processing estimation sets sketching)

Links for 2013-06-24

Published June 24, 2013

Links for 2013-06-21

Published June 21, 2013

  • Java Concurrent Counters By Numbers

    threadsafe counters in the JVM compared. AtomicLong, Doug Lea’s LongAdder, a ThreadLocal counter, and a field-on-the-Thread-object counter int (via Darach Ennis). Nitsan’s posts on concurrency are fantastic

    (tags: counters concurrency threads java jvm atomic)

  • Ultimate Tic-Tac-Toe

    Tic-Tac-Toe Inception. whoa

    (tags: games tic-tac-toe inception recursion boardgames via:fp)

  • hlld

    a high-performance C server which is used to expose HyperLogLog sets and operations over them to networked clients. It uses a simple ASCII protocol which is human readable, and similar to memcached. HyperLogLog’s are a relatively new sketching data structure. They are used to estimate cardinality, i.e. the unique number of items in a set. They are based on the observation that any bit in a “good” hash function is indepedenent of any other bit and that the probability of getting a string of N bits all set to the same value is 1/(2^N). There is a lot more in the math, but that is the basic intuition. What is even more incredible is that the storage required to do the counting is log(log(N)). So with a 6 bit register, we can count well into the trillions. For more information, its best to read the papers referenced at the end. TL;DR: HyperLogLogs enable you to have a set with about 1.6% variance, using 3280 bytes, and estimate sizes in the trillions.
    (via:cscotta)

    (tags: hyper-log-log hlld hll data-structures memcached daemons sketching estimation big-data cardinality algorithms via:cscotta)

  • SSL/TLS overhead

    ‘The TLS handshake has multiple variations, but let’s pick the most common one – anonymous client and authenticated server (the connections browsers use most of the time).’ Works out to 4 packets, in addition to the TCP handshake’s 3, and about 6.5k bytes on average.

    (tags: network tls ssl performance latency speed networking internet security packets tcp handshake)

  • McLibel leaflet was co-written by undercover police officer Bob Lambert | UK news | guardian.co.uk

    The true identity of one of the authors of the “McLibel leaflet” is Bob Lambert, a police officer who used the alias Bob Robinson in his five years infiltrating the London Greenpeace group. […] McDonald’s famously sued green campaigners over the roughly typed leaflet, in a landmark three-year high court case, that was widely believed to have been a public relations disaster for the corporation. Ultimately the company won a libel battle in which it spent millions on lawyers. Lambert was deployed by the special demonstration squad (SDS) – a top-secret Metropolitan police unit that targeted political activists between 1968 until 2008, when it was disbanded. He co-wrote the defamatory six-page leaflet in 1986 – and his role in its production has been the subject of an internal Scotland Yard investigation for several months. At no stage during the civil legal proceedings brought by McDonald’s in the 1990s was it disclosed that a police infiltrator helped author the leaflet.

    (tags: infiltration police mcdonalds libel greenpeace bob-lambert undercover 1980s uk-politics)

Links for 2013-06-20

Published June 20, 2013

  • Project Voldemort: measuring BDB space consumption

    HOWTO measure this using the BDB-JE command line tools. this is exposed through JMX as the CleanerBacklog metric, too, I think, but good to bookmark just in case

    (tags: voldemort cleaner bdb ops space storage monitoring debug)

  • rendering pcm with simulated phosphor persistence

    This is something readily applicable to display of sampled time-series metric data — it really makes regular patterns visible (and is nicely retro to boot).

    When PCM waveforms and similar function plots are displayed on screen, computational speed is often preferred over beauty and information content. For example, Audacity only draws the local maximum envelope amplitude and (what appears to be) RMS power when zoomed out, and when zoomed in, displays a very straightforward linear interpolation between samples. Analogue oscilloscopes, on the other hand, do things differently. An electron beam scans a phosphor screen at a constant X velocity, lighting a dot everywhere it hits. The dot brightness is proportional to the time the electron beam was directed at it. Because the X speed of the beam is constant and the Y position is modulated by the waveform, brightness gives information about the local derivative of the function. Now how cool is that? It looks like an X-ray of the signal. We can see right away that the beep is roughly a square wave, because there’s light on top and bottom of the oscillation envelope but mostly darkness in between. Minute changes in the harmonic content are also visible as interesting banding and ribbons.
    (via an _amazing_ kragen post on ghetto electronics)

    (tags: via:kragen pcm waveforms oscilloscopes analog analogue dataviz time-series waves ui phosphor retro)

  • stuff Google has learned from their hiring data

    A. On the hiring side, we found that [interview] brainteasers are a complete waste of time. How many golf balls can you fit into an airplane? How many gas stations in Manhattan? A complete waste of time. They don’t predict anything. They serve primarily to make the interviewer feel smart. Instead, what works well are structured behavioral interviews, where you have a consistent rubric for how you assess people, rather than having each interviewer just make stuff up. Behavioral interviewing also works — where you’re not giving someone a hypothetical, but you’re starting with a question like, “Give me an example of a time when you solved an analytically difficult problem.” The interesting thing about the behavioral interview is that when you ask somebody to speak to their own experience, and you drill into that, you get two kinds of information. One is you get to see how they actually interacted in a real-world situation, and the valuable “meta” information you get about the candidate is a sense of what they consider to be difficult.
    This makes sense, and matches what I learned in Amazon. Bad news for Microsoft though! (Correction: Adam Shostack got in touch to note that MS haven’t done this for 10+ years either.)

    Also, I like this:

    A. One of the things we’ve seen from all our data crunching is that G.P.A.’s are worthless as a criteria for hiring, and test scores are worthless — no correlation at all except for brand-new college grads, where there’s a slight correlation. Google famously used to ask everyone for a transcript and G.P.A.’s and test scores, but we don’t anymore, unless you’re just a few years out of school. We found that they don’t predict anything. What’s interesting is the proportion of people without any college education at Google has increased over time as well. So we have teams where you have 14 percent of the team made up of people who’ve never gone to college.

    (tags: google hiring interviewing interviews brainteasers gpa microsoft star amazon)

Links for 2013-06-19

Published June 19, 2013

  • Java Garbage Collection Distilled

    Martin Thompson lays it out:

    Serial, Parallel, Concurrent, CMS, G1, Young Gen, New Gen, Old Gen, Perm Gen, Eden, Tenured, Survivor Spaces, Safepoints, and the hundreds of JVM start-up flags. Does this all baffle you when trying to tune the garbage collector while trying to get the required throughput and latency from your Java application? If it does then don’t worry, you are not alone. Documentation describing garbage collection feels like man pages for an aircraft. Every knob and dial is detailed and explained but nowhere can you find a guide on how to fly. This article will attempt to explain the tradeoffs when choosing and tuning garbage collection algorithms for a particular workload.

    (tags: gc java garbage-collection coding cms g1 jvm optimization)

  • DRI needs your help

    Appalled by mass surveillance scandals? So are we. We’re doing something about it – and you can too. In 2006 we started a case challenging Irish and European laws that require your mobile phone company and ISP to monitor your location, your calls, your texts and your emails and to store that information for up to two years. That case has now made it to the European Court of Justice and will be heard on July 9th. If we are successful, it will strike down these laws for all of Europe and will declare illegal this type of mass surveillance of the entire population. Here’s where you come in. You can take part by: making a donation to help us pay for the expenses we incur; following our updates and keeping abreast of the issues; spreading the word on social media. With your help, we can strike a blow for the privacy of all citizens.

    (tags: activism privacy politics ireland dri digital-rights data-protection data-retention)

  • 3-D Printer Brings Dexterity To Children With No Fingers

    ‘A South African man who lost part of his hand in a home carpentry accident and an American puppeteer he met via YouTube have teamed up to make 3D-printable hands for children who have no fingers. So far, over 100 children have been given “robohands” for free, and a simplified version released just yesterday snaps together like LEGO bricks and costs just $5 in materials.’ This is incredible. Check out the video of Liam and his robohand in action: http://www.youtube.com/watch?v=kB53-D_N8Uc

    (tags: 3d-printing 3d makers robohands hands prosthetics future youtube via:gruverja)

Links for 2013-06-18

Published June 18, 2013

Links for 2013-06-17

Published June 17, 2013

  • Atelier olschinsky – “Cities III 05”

    Fine Art Print on Hahnemuehle Photo Rag Bright White, 310g: 40x50cm up to 70x100cm. Some great art based on decayed urban landscape shots, from a Vienna-based design studio. See also http://english.mashkulture.net/2011/10/17/atelier-olschinsky-cities-iii/ , http://www.mascontext.com/tag/atelier-olschinsky/

    (tags: olschinsky cities urban decay landscape art prints want)

  • Possible ban on ‘factory food’ in French restaurants

    I am very much in favour of this in Ireland, too. The pre-prepared food thing makes for crappy food:

    In an attempt to crack down on the proliferation of restaurants serving boil-in-a-bag or microwave-ready meals, which could harm France’s reputation for good food, MP Daniel Fasquelle is putting a new law to parliament this month. […] The proposed law would limit the right to use the word “restaurant” to eateries where food is prepared on site using raw ingredients, either fresh or frozen. Exceptions would be made for some prepared products, such as bread, charcuterie and ice cream.

    (tags: restaurants food france cuisine boil-in-the-bag microwave cooking daniel-fasquelle)

  • On Scala

    great, comprehensive review of the language, its pros and misfeatures, from Bill de hOra

    (tags: scala languages coding fp reviews)

  • Introducing Kale « Code as Craft

    Etsy have implemented a tool to perform auto-correlation of service metrics, and detection of deviation from historic norms:

    at Etsy, we really love to make graphs. We graph everything! Anywhere we can slap a StatsD call, we do. As a result, we’ve found ourselves with over a quarter million distinct metrics. That’s far too many graphs for a team of 150 engineers to watch all day long! And even if you group metrics into dashboards, that’s still an awful lot of dashboards if you want complete coverage. Of course, if a graph isn’t being watched, it might misbehave and no one would know about it. And even if someone caught it, lots of other graphs might be misbehaving in similar ways, and chances are low that folks would make the connection. We’d like to introduce you to the Kale stack, which is our attempt to fix both of these problems. It consists of two parts: Skyline and Oculus. We first use Skyline to detect anomalous metrics. Then, we search for that metric in Oculus, to see if any other metrics look similar. At that point, we can make an informed diagnosis and hopefully fix the problem.
    It’ll be interesting to see if they can get this working well. I’ve found it can be tricky to get working with low false positives, without massive volume to “smooth out” spikes caused by normal activity. Amazon had one particularly successful version driving severity-1 order drop alarms, but it used massive event volumes and still had periodic false positives. Skyline looks like it will alarm on a single anomalous data point, and in the comments Abe notes “our algorithms err on the side of noise and so alerting would be very noisy.”

    (tags: etsy monitoring service-metrics alarming deviation correlation data search graphs oculus skyline kale false-positives)

  • Paper: “Root Cause Detection in a Service-Oriented Architecture” [pdf]

    LinkedIn have implemented an automated root-cause detection system:

    This paper introduces MonitorRank, an algorithm that can reduce the time, domain knowledge, and human effort required to ?nd the root causes of anomalies in such service-oriented architectures. In the event of an anomaly, MonitorRank provides a ranked order list of possible root causes for monitoring teams to investigate. MonitorRank uses the historical and current time-series metrics of each sensor as its input, along with the call graph generated between sensors to build an unsupervised model for ranking. Experiments on real production outage data from LinkedIn, one of the largest online social networks, shows a 26% to 51% improvement in mean average precision in ?nding root causes compared to baseline and current state-of-the-art methods.
    This is a topic close to my heart after working on something similar for 3 years in Amazon! Looks interesting, although (a) I would have liked to see more case studies and examples of “real world” outages it helped with; and (b) it’s very much a machine-learning paper rather than a systems one, and there is no discussion of fault tolerance in the design of the detection system, which would leave me worried that in the case of a large-scale outage event, the system itself will disappear when its help is most vital. (This was a major design influence on our team’s work.) Overall, particularly given those 2 issues, I suspect it’s not in production yet. Ours certainly was ;)

    (tags: linkedin soa root-cause alarming correlation service-metrics machine-learning graphs monitoring)

  • Announcing Zuul: Edge Service in the Cloud

    Netflix’ library to implement “edge services” — ie. a front end to their API, web servers, and streaming servers. Some interesting features: dynamic filtering using Groovy scripts; Hystrix for software load balancing, fault tolerance, and error handling for originated HTTP requests; fine-grained service metrics; Archaius for configuration; and canary requests to detect overload risks. Pretty complex though

    (tags: edge-services api netflix zuul archaius canary-requests http groovy hystrix load-balancing fault-tolerance error-handling configuration)

  • CloudFlare, PRISM, and Securing SSL Ciphers

    Matthew Prince of CloudFlare has an interesting theory on the NSA’s capabilities:

    It is not inconceivable that the NSA has data centers full of specialized hardware optimized for SSL key breaking. According to data shared with us from a survey of SSL keys used by various websites, the majority of web companies were using 1024-bit SSL ciphers and RSA-based encryption through 2012. Given enough specialized hardware, it is within the realm of possibility that the NSA could within a reasonable period of time reverse engineer 1024-bit SSL keys for certain web companies. If they’d been recording the traffic to these web companies, they could then use the broken key to go back and decrypt all the transactions. While this seems like a compelling theory, ultimately, we remain skeptical this is how the PRISM program described in the slides actually works. Cracking 1024-bit keys would be a big deal and likely involve some cutting-edge cryptography and computational power, even for the NSA. The largest SSL key that is known to have been broken to date is 768 bits long. While that was 4 years ago, and the NSA undoubtedly has some of the best cryptographers in the world, it’s still a considerable distance from 768 bits to 1024 bits — especially given the slide suggests Microsoft’s key would have to had been broken back in 2007. Moreover, the slide showing the dates on which “collection began” for various companies also puts the cost of the program at $20M/year. That may sound like a lot of money, but it is not for an undertaking like this. Just the power necessary to run the server farm needed to break a 1024-bit key would likely cost in excess of $20M/year. While the NSA may have broken 1024-bit SSL keys as part of some other program, if the slide is accurate and complete, we think it’s highly unlikely they did so as part of the PRISM program. A not particularly glamorous alternative theory is that the NSA didn’t break the SSL key but instead just cajoled rogue employees at firms with access to the private keys — whether the companies themselves, partners they’d shared the keys with, or the certificate authorities who issued the keys in the first place — to turn them over. That very well may be possible on a budget of $20M/year. [….] Google is a notable anomaly. The company uses a 1024-bit key, but, unlike all the other companies listed above, rather than using a default cipher suite based on the RSA encryption algorithm, they instead prefer the Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) cipher suites. Without going into the technical details, a key difference of ECDHE is that they use a different private key for each user’s session. This means that if the NSA, or anyone else, is recording encrypted traffic, they cannot break one private key and read all historical transactions with Google. The NSA would have to break the private key generated for each session, which, in Google’s case, is unique to each user and regenerated for each user at least every 28-hours. While ECDHE arguably already puts Google at the head of the pack for web transaction security, to further augment security Google has publicly announced that they will be increasing their key length to 2048-bit by the end of 2013. Assuming the company continues to prefer the ECDHE cipher suites, this will put Google at the cutting edge of web transaction security.
    2048-bit ECDHE sounds like the way to go, and CloudFlare now support that too.

    (tags: prism security nsa cloudflare ssl tls ecdhe elliptic-curve crypto rsa key-lengths)

  • Record companies to target 20 more pirate sites after court ruling – Independent.ie

    Looks like IRMA are following the lead of the UK’s BPI, by chasing the proxy sites next:

    Up to 20 internet sites are to be targeted by an organisation representing record companies in a move to stamp out the illegal pirating of music and other copyright material. The Irish Recorded Music Association (IRMA) said it would be immediately moving against the 20 “worst offenders” to “take out” internet sites involved in the illegal downloading of copyright work.
    However, looks like this will involve more court time:
    Last night IRMA director general, Dick Doyle said the High Court ruling was only the first step in “taking out many internet sites involved in illegally downloading music. “We will be back in court very shortly to take out five to 10 other sites. We have already selected a total of 20 of the worst offender sites and we will go after the next five in the very near future,” he said.
    That’s not going to be cheap!

    (tags: courts ireland law irma piracy pirate-bay bpi proxies filesharing copyright)

  • Building a Modern Website for Scale (QCon NY 2013) [slides]

    some great scalability ideas from LinkedIn. Particularly interesting are the best practices suggested for scaling web services: 1. store client-call timeouts and SLAs in Zookeeper for each REST endpoint; 2. isolate backend calls using async/threadpools; 3. cancel work on failures; 4. avoid sending requests to GC’ing hosts; 5. rate limits on the server. #4 is particularly cool. They do this using a “GC scout” request before every “real” request; a cheap TCP request to a dedicated “scout” Netty port, which replies near-instantly. If it comes back with a 1-packet response within 1 millisecond, send the real request, else fail over immediately to the next host in the failover set. There’s still a potential race condition where the “GC scout” can be achieved quickly, then a GC starts just before the “real” request is issued. But the incidence of GC-blocking-request is probably massively reduced. It also helps against packet loss on the rack or server host, since packet loss will cause the drop of one of the TCP packets, and the TCP retransmit timeout will certainly be higher than 1ms, causing the deadline to be missed. (UDP would probably work just as well, for this reason.) However, in the case of packet loss in the client’s network vicinity, it will be vital to still attempt to send the request to the final host in the failover set regardless of a GC-scout failure, otherwise all requests may be skipped. The GC-scout system also helps balance request load off heavily-loaded hosts, or hosts with poor performance for other reasons; they’ll fail to achieve their 1 msec deadline and the request will be shunted off elsewhere. For service APIs with real low-latency requirements, this is a great idea.

    (tags: gc-scout gc java scaling scalability linkedin qcon async threadpools rest slas timeouts networking distcomp netty tcp udp failover fault-tolerance packet-loss)

  • Why I won’t give the European Parliament the data protection analysis it wanted

    Holy crap. Simon Davies rips into the EU data-protection reform disaster with gusto:

    The situation was an utter disgrace. The advertising industry even gave an award to an Irish Minister for destroying some of the rights in the regulation while the UK managed to force a provision that would make the direct marketing industry a “legitimate” processing operation in its own right, putting it on the same level of lawful processing as fraud prevention. Things got to the point where even the most senior data protection officials in Europe stopped trying to influence events and had told me “let the chips fall as they may”. […] But let’s take a step back for a moment from this travesty. Out on the streets – while most may not know what data protection is – people certainly know what it is supposed to protect. People value their privacy and they will be vocal about attempts to destroy it. I had said as much to the joint parliamentary meeting, observing “the one element that has been left out of all these efforts is the public”. However, as the months rolled on, the only message being sent to the public was that data protection is an anachronism stitched together with self interest and impracticality. […] I wasn’t aware at the time that there was a vast stitch-up to kill the reforms. I cannot bring myself to present a temperate report with measured wording that pretends this is all just normal business. It isn’t normal business, and it should never be normal business in any civilized society. How does one talk in measured tones about such endemic hypocrisy and deception? If you want to know who the real enemy of privacy is, don’t just look to the American agencies. The real enemy is right here in the European Parliament in the guise of MEPs who have knowingly sold our rights away to maintain powerful relationships. I’d like to say they were merely hoodwinked into supporting the vandalism, but many are smart people who knew exactly what they were doing.
    Nice work, Irish presidency! His bottom line:
    Is there a way forward? I believe so. First, governments should yield to common decency and scrap the illegitimate and poisoned Irish Council draft and hand the task to the Lithuanian Presidency that commences next month. Second, the Irish and British governments should be infinitely more transparent about their cooperation with intrusive interests that fuelled the deception.

    (tags: ireland eu europe reform law data-protection privacy simon-davies meps iab)

  • Persuading David Simon (Pinboard Blog)

    Maciej Ceglowski with a strongly-argued rebuttal of David Simon’s post about the NSA’s PRISM. This point in particular is key:

    The point is, you don’t need human investigators to find leads, you can have the algorithms do it [based on the call graph or network of who-calls-who]. They will find people of interest, assemble the watch lists, and flag whomever you like for further tracking. And since the number of actual terrorists is very, very, very small, the output of these algorithms will consist overwhelmingly of false positives.

    (tags: false-positives maciej privacy security nsa prism david-simon accuracy big-data filtering anti-spam)

  • Schneier on Security: Blowback from the NSA Surveillance

    Unintended consequences on US-focused governance of the internet and cloud computing:

    Writing about the new Internet nationalism, I talked about the ITU meeting in Dubai last fall, and the attempt of some countries to wrest control of the Internet from the US. That movement just got a huge PR boost. Now, when countries like Russia and Iran say the US is simply too untrustworthy to manage the Internet, no one will be able to argue. We can’t fight for Internet freedom around the world, then turn around and destroy it back home. Even if we don’t see the contradiction, the rest of the world does.

    (tags: internet freedom cloud-computing amazon google hosting usa us-politics prism nsa surveillance)

Links for 2013-06-15

Published June 15, 2013

  • EU unlocks a great new source of online innovation

    Today the European Parliament voted to formally agree new rules on open data – effectively making a reality of the proposal which I first put forward just over 18 months ago, and making it easier to open up huge amounts of public sector data.
    Great news — wonder how it’ll affect the Ordnance Survey of Ireland?

    (tags: osi mapping open-data open data europe eu neelie-kroes)

  • UK ISPs Secretly Start Blocking Torrent Site Proxies | TorrentFreak

    The next step of cat-and-mouse. Let’s see what the pirate sites do next…

    The blocking orders are intended to deter online piracy and were requested by the music industry group BPI on behalf of a variety of major labels. Thus far they’ve managed to block access to The Pirate Bay, Kat.ph, H33T and Fenopy, and preparations are being made to add many others. The effectiveness of these initial measures has been called into doubt, as they are relatively easy to bypass. For example, in response to the blockades hundreds of proxy sites popped up, allowing subscribers to reach the prohibited sites via a detour. However, as of this week these proxies are also covered by the same blocklist they aim to circumvent, without a new court ruling. The High Court orders give music industry group BPI the authority to add sites to the blocklist without oversight. Until now some small changes have been made, mostly in response to The Pirate Bay’s domain hopping endeavors, but with the latest blocklist update a whole new range of websites is being targeted.

    (tags: bittorrent blocking filesharing copyright bpi piracy pirate-bay proxies fenopy kat.ph h33t filtering uk)

Links for 2013-06-14

Published June 14, 2013

  • There’s a map for that

    ‘Not long ago, we began rendering 3D models on GitHub. Today we’re excited to announce the latest addition to the visualization family – geographic data. Any .geojson file in a GitHub repository will now be automatically rendered as an interactive, browsable map, annotated with your geodata.’ As this HN comment notes, https://news.ycombinator.com/item?id=5875693 — ‘I’d much rather Github cleaned up the UI for existing features than added these little flourishes that I can’t imagine even 1% of users use.’ Something is seriously wrong in how GitHub decides product direction if this kind of wankology (and that Judy-array crap) is what gets prioritised. :( (via Marc O’Morain)

    (tags: via:marc github mapping maps geojson hacking product-management ui pull-requests)

  • Lawsuit Filed To Prove Happy Birthday Is In The Public Domain; Demands Warner Pay Back Millions Of License Fees | Techdirt

    The issue […] is that it’s just not cost effective for anyone to actually stand up and challenge Warner Music, who has strong financial incentive to pretend the copyright is still valid. Well, apparently, someone is pissed off enough to try. The creatively named Good Morning to You Productions, a documentary film company planning a film about the song Happy Birthday, has now filed a lawsuit concerning the copyright of Happy Birthday and are seeking to force Warner/Chappell to return the millions of dollars it has collected over the years. That’s going to make this an interesting case.

    (tags: music copyright law via:bwalsh public-domain happy-birthday songs warner-music lawsuits)

  • graphite-metrics

    metric collectors for various stuff not (or poorly) handled by other monitoring daemons Core of the project is a simple daemon (harvestd), which collects metric values and sends them to graphite carbon daemon (and/or other configured destinations) once per interval. Includes separate data collection components (“collectors”) for processing of: /proc/slabinfo for useful-to-watch values, not everything (configurable). /proc/vmstat and /proc/meminfo in a consistent way. /proc/stat for irq, softirq, forks. /proc/buddyinfo and /proc/pagetypeinfo (memory fragmentation). /proc/interrupts and /proc/softirqs. Cron log to produce start/finish events and duration for each job into a separate metrics, adapts jobs to metric names with regexes. Per-system-service accounting using systemd and it’s cgroups. sysstat data from sadc logs (use something like sadc -F -L -S DISK -S XDISK -S POWER 60 to have more stuff logged there) via sadf binary and it’s json export (sadf -j, supported since sysstat-10.0.something, iirc). iptables rule “hits” packet and byte counters, taken from ip{,6}tables-save, mapped via separate “table chain_name rule_no metric_name” file, which should be generated along with firewall rules (I use this script to do that).
    Pretty exhaustive list of system metrics — could have some interesting ideas for Linux OS-level metrics to monitor in future.

    (tags: graphite monitoring metrics unix linux ops vm iptables sysadmin)

  • Former NSA Boss: We Don’t Data Mine Our Giant Data Collection, We Just Ask It Questions

    ‘Well, that’s – no, we’re going to use it. But we’re not going to use it in the way that some people fear. You put these records, you store them, you have them. It’s kind of like, I’ve got the haystack now. And now let’s try to find the needle. And you find the needle by asking that data a question. I’m sorry to put it that way, but that’s fundamentally what happens. All right. You don’t troll through the data looking for patterns or anything like that. The data is set aside. And now I go into that data with a question that – a question that is based on articulable(ph), arguable, predicate to a terrorist nexus.’
    Yep, that’s data mining.

    (tags: data-mining questions haystack needle nsa usa politics privacy data-protection michael-hayden)

  • fastutil

    fastutil extends the Java™ Collections Framework by providing type-specific maps, sets, lists and queues with a small memory footprint and fast access and insertion; provides also big (64-bit) arrays, sets and lists, and fast, practical I/O classes for binary and text files. It is free software distributed under the Apache License 2.0. It requires Java 6 or newer.
    used by Facebook (along with Apache Giraph, Netty, Unsafe) to speed up “weekend Hive jobs” to “coffee breaks”. http://www.slideshare.net/nitayj/2013-0603-berlin-buzzwords

    (tags: via:highscalability facebook giraph optimization java speed fastutil collections data-structures)

  • Big Memory, Part 4

    good microbenchmarking of a bunch of Java collections; Trove, fastutil, PCJ, mahout-collections, hppc

    (tags: java collections benchmarks performance speed coding data-structures optimization)

Links for 2013-06-13

Published June 13, 2013

  • Spamalot reigns: the spoils of Ireland’s EU kingship | The Irish Times – Thu, Jun 13, 2013

    The spam presidency. As European citizens are made the miserable targets of unimpeded “direct marketing”, that may be how Ireland’s stint in the EU presidency seat is recalled for years to come. Under the guiding hand of Minister for Justice Alan Shatter, the Council of the European Union has submitted proposals for amendments to a proposed new data protection regulation, all of which overwhelmingly favour business and big organisations, not citizens. The most obviously repugnant and surprising element in the amendments is a watering down of existing protections for EU citizens against the willy-nilly marketing Americans are forced to endure. In the US there are few meaningful restrictions on what businesses can do with people’s personal information when pitching products and services at them. In the EU, this has always been strictly controlled; information gathered for one purpose cannot be used by a business to sell whatever it wants – unless you have opted in to receive such solicitations. This means you are not constantly bombarded by emails and junk mail, nor do you get non-stop phone calls from telemarketers. Under the proposed amendments to the draft data protection regulation, direct marketing would become a legal form of data processing. In effect, this would legitimise spam email, junk print mail and marketing calls. This unexpected provision signals just how successful powerful corporate lobbyists have been in convincing ministers that business matters more than privacy or giving citizens reasonable control over their personal information. Far worse is contained in other amendments, which in effect turn the original draft of the regulation upside down.
    Fantastic article from Karlin Lillington in today’s Times on the terrible amendments proposed for the EU’s data protection law.

    (tags: eu law prism data-protection privacy ireland ec marketing spam anti-spam email)

Links for 2013-06-12

Published June 12, 2013

  • Vagrant and Chef to provision dev test environments

    We have recently switched from a manually configured development environment to a nearly fully automated one using Vagrant, Chef, and a few other tools. With this transition, we’ve moved to an environment where data on the dev boxes is considered disposable and only what’s checked into the SCM is “real”. This is where we’ve always wanted to be, but without the ability to easily rebuild the dev environment from scratch, it’s hard to internalize this behavior pattern.

    (tags: dev osx chef vagrant testing vms coding)

  • Rapid Response: The NSA Prism Leak

    ‘The biggest leak in the history of US security or nothing to worry about? A breach of trust and a data protection issue or a necessary secret project to protect American interests? [Tomorrow] lunchtime Science Gallery Rapid Response event [sic] will pick through the jargon, examine the minutiae of the National Security Agency’s PRISM project and the whistle blower Edward Snowden’s revelations, and discuss what it means for you and everyone. And we’ll look at the bigger picture too. Journalist Una Mullally will chair a panel of guests on the story that everyone is talking about. ‘

    (tags: science-gallery panel-discussions dublin nsa prism panel)

  • Music firms secure orders blocking access to Pirate Bay – Crime & Law News from Ireland & Abroad | The Irish Times – Wed, Jun 12, 2013

    Four major music companies have secured court orders requiring six internet service providers to block access by subscribers to various Pirate Bay websites within some 30 days in a bid to prevent illegal downloading of copyright music and other material. […] Today, Mr Justice Brian McGovern said he was satisfied to make the order in circumstances including that new copyright laws here and in the EU permitted such orders to be made. He said he fully agreed with a previous High Court judge who had said he would make such blocking orders if the law permitted and noted the law now allowed for such orders. The form of the orders means the music companies will not have to make fresh applications to court if Pirate Bay changes its location on the internet.

    (tags: pirate-bay blocking filtering internet ireland upc eircom vodafone digiweb three imagine o2 copyright)

  • Labour TD ignores tough questions on web case

    I [Tom Murphy] have asked [Sean Sherlock] a question: Does he have any comment about the lawsuit between EMI and UPC (and a raft of other ISPs too btw) which is using his SI to attempt to block PirateBay? A court case he said would not happen. Now, I am blocked from following him on Twitter. This is not how a proper political system works.

    (tags: politics ireland twitter sean-sherlock tom-murphy boards devore copyright)

Links for 2013-06-11

Published June 11, 2013

  • PRISM explains the wider lobbying issues surrounding EU data protection reform | EDRI

    The US has very successfully and expertly lobbied against the [EU] data protection package directly, it has mobilised and supported US industry lobbying. US industry has lobbied in its own name and mobilised malleable European trade associations to lobby on their behalf to amplify their message, “independent” “think tanks” have been created to amplify their message again. The result is not just the biggest lobbying effort that Brussels has ever seen, but also the broadest. Compliant Members of the European Parliament (MEPs) and EU Member States […] have been imposing a “death by a thousand cuts” on the Regulation. Where previously there was a clear obligation to collect the “minimum necessary” data for any given service, the vague requirement to retain “not excessive” data is now preferred. Where previously companies could only use data for purposes that were “compatible” with the original reason for collecting the data, the Irish EU Presidency (pdf) has proposed a comical definition of “compatible” based on five elements, only one of which is related to the dictionary definition of the word. Members of the European Parliament and EU Member States are falling over themselves to ensure that the EU does not maintain its strategic advantage over the US. In addition to dismantling the proposed Regulation, countries like the UK desperately seek to delay the whole process and subsume it into the EU-US free trade agreement (the so-called “investment partnership” TTIP/TAFTA), which would subordinate a fundamental rights discussion in a trade negotiation. The UK government is even prepared to humiliate itself by arguing in favour of the US position on the basis that two and a half years (see Communication from 2010, pdf) of discussion is too fast!

    (tags: edri data-protection eu ec ireland politics usa meps privacy uk free-trade)

Links for 2013-06-10

Published June 10, 2013

  • Microsoft admits US government can access EU-based cloud data

    interesting point from an MS Q&A back in 2011, quite relevant nowadays:

    Q: Can Microsoft guarantee that EU-stored data, held in EU based datacenters, will not leave the European Economic Area under any circumstances — even under a request by the Patriot Act? A: Frazer explained that, as Microsoft is a U.S.-headquartered company, it has to comply with local laws (the United States, as well as any other location where one of its subsidiary companies is based). Though he said that “customers would be informed wherever possible,” he could not provide a guarantee that they would be informed — if a gagging order, injunction or U.S. National Security Letter permits it. He said: “Microsoft cannot provide those guarantees. Neither can any other company.” While it has been suspected for some time, this is the first time Microsoft, or any other company, has given this answer. Any data which is housed, stored or processed by a company, which is a U.S. based company or is wholly owned by a U.S. parent company, is vulnerable to interception and inspection by U.S. authorities. 

    (tags: microsoft privacy cloud-computing eu data-centers data-protection nsa fisa usa)

Links for 2013-06-09

Published June 9, 2013

  • IAB Europe awards MEP Sean Kelly for standing up for data privacy rights (video) – Ireland’s CIO and strategy news and reports service – Siliconrepublic.com

    Irish MEP serving as a rapporteur on reform of the EU data protection regime, was given an award by an advertising trade group last month:

    Sean Kelly, Fine Gael MEP for Ireland South [who serves as the EU’s Industry Committee Rapporteur for the General Data Protection Regulation], has been selected to receive the prestigious IAB Europe Award for Leadership and Excellence for his approach to dealing with privacy concerns over shortcomings in the European Commission’s data protection proposal. IAB Europe represents more than 5,500 online advertising media, research and analytics organisations.

    (tags: iab-europe awards spam sean-kelly ireland meps politics eu data-protection privacy ec)

  • The CAP FAQ by henryr

    No subject appears to be more controversial to distributed systems engineers than the oft-quoted, oft-misunderstood CAP theorem. The purpose of this FAQ is to explain what is known about CAP, so as to help those new to the theorem get up to speed quickly, and to settle some common misconceptions or points of disagreement.

    (tags: database distributed nosql cap consistency cap-theorem faqs)

  • seeing into the UV spectrum after Cataract Surgery with Crystalens

    I’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)

    (tags: via:fanf science perception augmentation uv light sight cool cataracts surgery lens eyes)

  • Instagram: Making the Switch to Cassandra from Redis, a 75% ‘Insta’ Savings

    shifting data out of RAM and onto SSDs — unsurprisingly, big savings.

    a 12 node cluster of EC2 hi1.4xlarge instances; we store around 1.2TB of data across this cluster. At peak, we’re doing around 20,000 writes per second to that specific cluster and around 15,000 reads per second. We’ve been really impressed with how well Cassandra has been able to drop into that role.

    (tags: ram ssd cassandra databases nosql redis instagram storage ec2)

  • Council of the European Union Releases Draft Compromise Text on the Proposed EU Data Protection Regulation

    Oh god. this sounds like an impending privacy and anti-spam disaster. “business-focussed”:

    Overall, the [Irish EC Presidency’s] draft compromise text can be seen as a more business-focused, pragmatic approach. For example, the Presidency has drafted an additional recital (Recital 3a), clarifying the right to data protection as a qualified right, highlighting the principle of proportionality and importance of other competing fundamental rights, including the freedom to conduct a business.
    and some pretty serious relaxation of how consent for use of personal data is measured:
    The criterion for valid consent is amended from “explicit” to “unambiguous,” except in the case of processing special categories of data (i.e., sensitive personal data) (Recital 25 and Article 9(2)). This reverts to the current position under the Data Protection Directive and is a concession to the practical difficulty of obtaining explicit consent in all cases. The criteria for valid consent are further relaxed by the ability to obtain consent in writing, orally or in an electronic manner, and where technically feasible and effective, valid consent can be given using browser settings and other technical solutions. Further, the requirement that the controller bear the burden of proof that valid consent was obtained is limited to a requirement that the controller be able to “demonstrate” that consent was obtained (Recital 32 and Article 7(1)). The need for “informed” consent is also relaxed from the requirement to provide the full information requirements laid out in Article 14 to the minimal requirements that the data subject “at least” be made aware of: (1) the identity of the data controller, and (2) the purpose(s) of the processing of their personal data (Recitals 33 and 48).

    (tags: anti-spam privacy data-protection spam ireland eu ec regulation)

  • LobbyPlag

    wow, great view of which MEPs are eviscerating the EU’s data protection regime:

    Currently the EU is negotiating about new data privacy laws. This new EU Regulation will replace all existing national laws on data privacy. Here you can see a general overview which Members of the European Parliament (MEPs) are pushing for more or less data privacy. Choose a country, a political group or a MEP from the “Top 10” list to find out more.

    (tags: europe eu privacy data-protection datap ec regulation meps)

Links for 2013-06-06

Published June 6, 2013

Links for 2013-06-05

Published June 5, 2013

  • Care and Feeding of Large Scale Graphite Installations [slides]

    good docs for large-scale graphite use: ‘Tip and tricks of using and scaling graphite. First presented at DevOpsDays Austin Texas 2013-05-01’

    (tags: graphite devops ops metrics dashboards sysadmin)

  • Low-latency stock trading “jumps the gun” due to default NTP configuration settings

    On June 3, 2013, trading in SPY exploded at 09:59:59.985, which is 15 milliseconds before the ISM’s Manufacturing number released at 10:00:00. Activity in the eMini (traded in Chicago), exploded at 09:59:59.992, which is 8 milliseconds before the news release, but 7 milliseconds after SPY. Note how SPY and the eMini traded within a millisecond for the Consumer Confidence release last week, but the eMini lagged SPY by about 7 milliseconds for the ISM Manufacturing release. The simultaneous trading on Consumer Confidence is because that number is released at the same time in both NYC and Chicago. The ISM Manufacturing number is probably released on a low latency feed in NYC, and then takes 5-7 milliseconds, due to the speed of light, to reach Chicago. Either the clock used to release the ISM number was 15 milliseconds fast, or someone (correctly) jumped the gun. Update: […] The clock used to release the ISM was indeed, 15 milliseconds fast. This could be from using the default setting of many NTP clients, which allows the clock to drift up to about 16 milliseconds before adjusting time.

    (tags: ntp time synchronization spy trading stocks low-latency clocks internet)

  • the infamous 2008 S3 single-bit-corruption outage

    Neat, I didn’t realise this was publicly visible. A single corrupted bit infected the S3 gossip network, taking down the whole S3 service in (iirc) one region:

    We’ve now determined that message corruption was the cause of the server-to-server communication problems. More specifically, we found that there were a handful of messages on Sunday morning that had a single bit corrupted such that the message was still intelligible, but the system state information was incorrect. We use MD5 checksums throughout the system, for example, to prevent, detect, and recover from corruption that can occur during receipt, storage, and retrieval of customers’ objects. However, we didn’t have the same protection in place to detect whether [gossip state] had been corrupted. As a result, when the corruption occurred, we didn’t detect it and it spread throughout the system causing the symptoms described above. We hadn’t encountered server-to-server communication issues of this scale before and, as a result, it took some time during the event to diagnose and recover from it. During our post-mortem analysis we’ve spent quite a bit of time evaluating what happened, how quickly we were able to respond and recover, and what we could do to prevent other unusual circumstances like this from having system-wide impacts. Here are the actions that we’re taking: (a) we’ve deployed several changes to Amazon S3 that significantly reduce the amount of time required to completely restore system-wide state and restart customer request processing; (b) we’ve deployed a change to how Amazon S3 gossips about failed servers that reduces the amount of gossip and helps prevent the behavior we experienced on Sunday; (c) we’ve added additional monitoring and alarming of gossip rates and failures; and, (d) we’re adding checksums to proactively detect corruption of system state messages so we can log any such messages and then reject them.
    This is why you checksum all the things ;)

    (tags: s3 aws post-mortems network outages failures corruption grey-failures amazon gossip)

Links for 2013-06-04

Published June 4, 2013

  • The network is reliable

    Aphyr and Peter Bailis collect an authoritative list of known network partition and outage cases from published post-mortem data:

    This post is meant as a reference point — to illustrate that, according to a wide range of accounts, partitions occur in many real-world environments. Processes, servers, NICs, switches, local and wide area networks can all fail, and the resulting economic consequences are real. Network outages can suddenly arise in systems that are stable for months at a time, during routine upgrades, or as a result of emergency maintenance. The consequences of these outages range from increased latency and temporary unavailability to inconsistency, corruption, and data loss. Split-brain is not an academic concern: it happens to all kinds of systems — sometimes for days on end. Partitions deserve serious consideration.
    I honestly cannot understand people who didn’t think this was the case. 3 years reading (and occasionally auto-cutting) Amazon’s network-outage tickets as part of AWS network monitoring will do that to you I guess ;)

    (tags: networking outages partition cap failure fault-tolerance)

  • Cities 05

    from Atelier Olschinsky. ‘Fine Art Print on Hahnemuehle Photo Rag Bright White 310g; Limited Edition / Numbered and signed by the artist’

    (tags: art graphics cities prints want via:bdif)

Links for 2013-05-30

Published May 30, 2013

  • incompetent error-handling code in the mongo-java-driver project

    an unexplained invocation of Math.random() in the exception handling block of this MongoDB java driver class causes roflscale lols in the github commit notes. http://stackoverflow.com/a/16833798 has more explanation.

    (tags: github commits mongodb webscale roflscale random daily-wtf wtf)

  • Hermetic Servers

    ‘What is a Hermetic Server? The short definition would be a “server in a box”. If you can start up the entire server on a single machine that has no network connection AND the server works as expected, you have a hermetic server! This is a special case of the more general “hermetic” concept which applies to an isolated system not necessarily on a single machine. Why is it useful to have a hermetic server? Because if your entire [system under test] is composed of hermetic servers, it could all be started on a single machine for testing; no network connection necessary! The single machine could be a physical or virtual machine.’ These also qualify as “fakes”, using the terminology Martin Fowler suggests at http://martinfowler.com/bliki/TestDouble.html , I think

    (tags: google testing hermetic-servers test test-doubles unit-testing)

  • Don’t Overuse Mocks

    hooray, sanity from the Google Testing blog. this has been a major cause of pain in the past, dealing with tricky rewrites of mock-heavy unit test code

    (tags: mocking testing tests google mocks unit-testing)

Links for 2013-05-29

Published May 29, 2013

  • Casalattico – Wikipedia, the free encyclopedia

    How wierd. Many of the well-known chippers in Ireland are run by families from the same comune in Italy.

    In the late 19th and early 20th century a significant number of young people left Casalattico to work in Ireland, with many founding chip shops there. Most second, third and fourth generation Irish-Italians can trace their lineage back to the municipality, with names such as Magliocco, Fusco, Marconi, Borza, Macari, Rosato and Forte being the most common. Although the Forte family actually originates from the village of Mortale, renamed Mon Forte due to the achievements of the Forte family. It is believed that up to 8,000 Irish-Italians have ancestors from Casalattico. The village is home to an Irish festival every summer to celebrate the many families that moved from there to Ireland.
    (via JK)

    (tags: rome lazio italy ireland chip-shops chippers history emigration casalattico work irish-italians via:jk)

  • Videos from the Continuous Delivery track at QCon SF 2012

    Think we’ll be watching some of these in work soon — Jez Humble’s talk (the last one) in particular looks good:

    Amazon, Etsy, Google and Facebook are all primarily software development shops which command enormous amounts of resources. They are, to use Christopher Little’s metaphor, unicorns. How can the rest of us adopt continuous delivery? That’s the subject of my talk, which describes four case studies of organizations that adopted continuous delivery, with varying degrees of success. One of my favourites – partly because it’s embedded software, not a website – is the story of HP’s LaserJet Firmware team, who re-architected their software around the principles of continuous delivery. People always want to know the business case for continuous delivery: the FutureSmart team provide one in the book they wrote that discusses how they did it.

    (tags: continuous-integration continuous-delivery build release process dev deployment videos qcon towatch hp)

  • _Dynamic Histograms: Capturing Evolving Data Sets_ [pdf]

    Currently, histograms are static structures: they are created from scratch periodically and their creation is based on looking at the entire data distribution as it exists each time. This creates problems, however, as data stored in DBMSs usually varies with time. If new data arrives at a high rate and old data is likewise deleted, a histogram’s accuracy may deteriorate fast as the histogram becomes older, and the optimizer’s effectiveness may be lost. Hence, how often a histogram is reconstructed becomes very critical, but choosing the right period is a hard problem, as the following trade-off exists: If the period is too long, histograms may become outdated. If the period is too short, updates of the histogram may incur a high overhead. In this paper, we propose what we believe is the most elegant solution to the problem, i.e., maintaining dynamic histograms within given limits of memory space. Dynamic histograms are continuously updateable, closely tracking changes to the actual data. We consider two of the best static histograms proposed in the literature [9], namely V-Optimal and Compressed, and modify them. The new histograms are naturally called Dynamic V-Optimal (DVO) and Dynamic Compressed (DC). In addition, we modified V-Optimal’s partition constraint to create the Static Average-Deviation Optimal (SADO) and Dynamic Average-Deviation Optimal (DADO) histograms.
    (via d2fn)

    (tags: via:d2fn histograms streaming big-data data dvo dc sado dado dynamic-histograms papers toread)

Links for 2013-05-28

Published May 28, 2013

Links for 2013-05-27

Published May 27, 2013

Links for 2013-05-25

Published May 25, 2013

  • Instant artist statement: Arty Bollocks Generator

    ‘My work explores the relationship between the body and vegetarian ethics. With influences as diverse as Munch and Francis Bacon, new synergies are created from both orderly and random narratives. Ever since I was a postgraduate I have been fascinated by the essential unreality of the moment. What starts out as undefined soon becomes corroded into a hegemony of greed, leaving only a sense of failing and the chance of a new order. As temporal replicas become transformed through diligent and undefined practice, the viewer is left with an impression of the darkness of our culture.’

    (tags: funny humor art arty bollocks generator hacks via:leroideplywood)

Links for 2013-05-24

Published May 24, 2013

  • Communication costs in real-world networks

    Peter Bailis has generated some good real-world data about network performance and latency, measured using EC2 instances, between ec2 regions, between zones, and between hosts in a single AZ. good data (particularly as I was looking for this data in a public source not too long ago).

    I wasn’t aware of any datasets describing network behavior both within and across datacenters, so we launched m1.small Amazon EC2 instances in each of the eight geo-distributed “Regions,” across the three us-east “Availability Zones” (three co-located datacenters in Virginia), and within one datacenter (us-east-b). We measured RTTs between hosts for a week at a granularity of one ping per second.
    Some of the high-percentile measurements are undoubtedly impact of host and VM behaviour, but that is still good data for a typical service built in EC2.

    (tags: networks performance measurements benchmarks ops ec2 networking internet az latency)

Links for 2013-05-21

Published May 21, 2013

Links for 2013-05-20

Published May 20, 2013

  • Newegg nukes “corporate troll” Alcatel in third patent appeal win this year

    I am loving this. Particularly this:

    At trial in East Texas Cheng took the stand to tell Newegg’s story. Alcatel-Lucent’s corporate representative, at the heart of its massive licensing campaign, couldn’t even name the technology or the patents it was suing Newegg over. “Successful defendants have their litigation managed by people who care,” said Cheng. “For me, it’s easy. I believe in Newegg, I care about Newegg. Alcatel Lucent, meanwhile, they drag out some random VP—who happens to be a decorated Navy veteran, who happens to be handsome and has a beautiful wife and kids—but the guy didn’t know what patents were being asserted. What a joke.” “Shareholders of public companies that engage in patent trolling should ask themselves if they’re really well-served by their management teams,” Cheng added. “Are they properly monetizing their R&D? Surely there are better ways to make money than to just rely on litigating patents. If I was a shareholder, I would take a hard look as to whether their management was competent.”

    (tags: patents ip swpats alcatel bell-labs newegg east-texas litigation lucent)

  • Call me maybe: Carly Rae Jepsen and the perils of network partitions

    Kyle “aphyr” Kingsbury expands on his slides demonstrating the real-world failure scenarios that arise during some kinds of partitions (specifically, the TCP-hang, no clear routing failure, network partition scenario). Great set of blog posts clarifying CAP

    (tags: distributed network databases cap nosql redis mongodb postgresql riak crdt aphyr)

  • The $12 Gongkai Phone

    Welcome to the Galapagos of Chinese “open” source. I call it “gongkai” (??). Gongkai is the transliteration of “open” as applied to “open source”. I feel it deserves a term of its own, as the phenomenon has grown beyond the so-called “shanzhai” (??) and is becoming a self-sustaining innovation ecosystem of its own. Just as the Galapagos Islands is a unique biological ecosystem evolved in the absence of continental species, gongkai is a unique innovation ecosystem evolved with little western influence, thanks to political, language, and cultural isolation. Of course, just as the Galapagos was seeded by hardy species that found their way to the islands, gongkai was also seeded by hardy ideas that came from the west. These ideas fell on the fertile minds of the Pearl River delta, took root, and are evolving. Significantly, gongkai isn’t a totally lawless free-for-all. It’s a network of ideas, spread peer-to-peer, with certain rules to enforce sharing and to prevent leeching. It’s very different from Western IP concepts, but I’m trying to have an open mind about it.

    (tags: gongkai bunnie-huang china phone mobile hardware devices open-source)

  • Stability Patterns and Antipatterns [slides]

    Michael “Release It!” Nygard’s slides from a recent O’Reilly event, discussing large-scale service reliability design patterns

    (tags: michael-nygard design-patterns architecture systems networking reliability soa slides pdf)

Links for 2013-05-17

Published May 17, 2013

  • Deep In The Game: Not The RTE Guide

    Good interview with Alan Maguire, the satirist behind the very funny @NotTheRTEGuide on Twitter:

    I’ve always been a huge fan of TV Go Home and Charlie Brooker in general and it seemed like Irish TV and culture was a good target for the kind of barbed surrealism that he does. (I’m not claiming I’m in his league or anything but he’s the main influence). I was really surprised that there hadn’t been a parody RTÉ Guide already. TV listings are 140-ish characters already and the RTÉ Guide has a kind of weird place in Irish culture where everybody knows it but nobody our age really has any idea of what’s in it anymore. We associate it with a small-c conservatism, or I did at least and I play that up occasionally with the account.

    (tags: nottherteguide rte rte-guide ireland funny satire interviews)

  • My Philosophy on Alerting

    ‘based on my observations while I was a Site Reliability Engineer at Google.’ – by Rob Ewaschuk; very good, and matching the similar recommendations and best practices at Amazon for that matter

    (tags: monitoring ops devops alerting alerts pager-duty via:jk)

Links for 2013-05-16

Published May 16, 2013

  • Monitoring the Status of Your EBS Volumes

    Page in the AWS docs which describes their derived metrics and how they are computed — these are visible in the AWS Management Console, and alarmable, but not viewable in the Cloudwatch UI. grr. (page-joshea!)

    (tags: ebs aws monitoring metrics ops documentation cloudwatch)

  • Interpol filter scope creep: ASIC ordering unilateral website blocks

    Bloody hell. This is stupidity of the highest order, and a canonical example of “filter creep” by a government — secret state censorship of 1200 websites due to a single investment scam site.

    The Federal Government has confirmed its financial regulator has started requiring Australian Internet service providers to block websites suspected of providing fraudulent financial opportunities, in a move which appears to also open the door for other government agencies to unilaterally block sites they deem questionable in their own portfolios. The instrument through which the ISPs are blocking the Interpol list of sites is Section 313 of the Telecommunications Act. Under the Act, the Australian Federal Police is allowed to issue notices to telcos asking for reasonable assistance in upholding the law. […] Tonight Senator Conroy’s office revealed that the incident that resulted in Melbourne Free University and more than a thousand other sites being blocked originated from a different source — financial regulator the Australian Securities and Investment Commission. On 22 March this year, ASIC issued a media release warning consumers about the activities of a cold-calling investment scam using the name ‘Global Capital Wealth’, which ASIC said was operating several fraudulent websites — www.globalcapitalwealth.com and www.globalcapitalaustralia.com. In its release on that date, ASIC stated: “ASIC has already blocked access to these websites.”

    (tags: scams australia filtering filter-creep false-positives isps asic fraud secrecy)

  • Obfuscatory pie-chart from Garda penalty-points corruption report

    “Twitter / gavinsblog: For sake of clarity here is helpful pie chart of the 95.4% of fixed charge notices not terminated #missingthepoint” Paging Edward Tufte: classic example of an obfuscatory pie-chart, diagramming the wrong thing misleadingly. By presenting it like this, it appears that the 95.4% of cases where fixed charge notices were issued by the guards are relevant to the discussion of the other classes; in reality, that means that 4.6% of cases, 37,000 cases, were terminated, some for good reasons, others for not, and it’s the difference between those two classes that are relevant. In my opinion, 2 separate pie charts would be better; one to show the dismissed-versus-undismissed count (which IMO could have been omitted entirely), and one to show the good-vs-not-so-good termination reason counts (which is the meat of the issue).

    (tags: dataviz visualisation data obfuscation gardai police corruption penalty-points)

  • Berkeley DB Java Edition Architecture [PDF]

    background white paper on the BDB-JE innards and design, from 2006. Still pretty accurate and good info

    (tags: bdb-je java berkeley-db bdb design databases pdf white-papers trees)

  • one Canadian judge’s 192-page judgement eviscerating the Freeman-on-the-Land and related “Organised Pseudolegal Commercial Argument” litigants

    This Court has developed a new awareness and understanding of a category of vexatious litigant. As we shall see, while there is often a lack of homogeneity, and some individuals or groups have no name or special identity, they (by their own admission or by descriptions given by others) often fall into the following descriptions: Detaxers; Freemen or Freemen-on-the-Land; Sovereign Men or Sovereign Citizens; Church of the Ecumenical Redemption International (CERI); Moorish Law; and other labels – there is no closed list. In the absence of a better moniker, I have collectively labelled them as Organized Pseudolegal Commercial Argument litigants [“OPCA litigants”], to functionally define them collectively for what they literally are. These persons employ a collection of techniques and arguments promoted and sold by ‘gurus’ (as hereafter defined) to disrupt court operations and to attempt to frustrate the legal rights of governments, corporations, and individuals.   Over a decade of reported cases have proven that the individual concepts advanced by OPCA litigants are invalid. What remains is to categorize these schemes and concepts, identify global defects to simplify future response to variations of identified and invalid OPCA themes, and develop court procedures and sanctions for persons who adopt and advance these vexatious litigation strategies.   One participant in this matter […] appears to be a sophisticated and educated person, but is also an OPCA litigant. One of the purposes of these Reasons is, through this litigant, to uncover, expose, collate, and publish the tactics employed by the OPCA community, as a part of a process to eradicate the growing abuse that these litigants direct towards the justice and legal system we otherwise enjoy in Alberta and across Canada. I will respond on a point-by-point basis to the broad spectrum of OPCA schemes, concepts, and arguments advanced in this action by [him].
    Via Ronan Lupton

    (tags: via:ronanlupton law canada legal freeman opca court tax judgements)

Links for 2013-05-15

Published May 15, 2013

  • Rusty’s API Design Manifesto

    This classic came up in discussions yesterday…

    In the Linux Kernel community Rusty Russell came up with a API rating scheme to help us determine if our API is sensible, or not.  It’s a rating from -10 to 10, where 10 is perfect is -10 is hell. Unfortunately there are too many examples at the wrong end of the scale.

    (tags: rusty-russell quality coding kernel linux apis design code-reviews code)

  • Sup relaunched

    hooray! Command-line gmailish goodness returns. And with a signed gem, to boot

    (tags: gems ruby sup mail gmail mua)

  • Martin Thompson, Luke “Snabb Switch” Gorrie etc. review the C10M presentation from Schmoocon

    on the mechanical-sympathy mailing list. Some really interesting discussion on handling insane quantities of TCP connections using low volumes of hardware:

    This talk has some good points and I think the subject is really interesting.  I would take the suggested approach with serious caution.  For starters the Linux kernel is nowhere near as bad as it made out.  Last year I worked with a client and we scaled a single server to 1 million concurrent connections with async programming in Java and some sensible kernel tuning.  I’ve heard they have since taken this to over 5 million concurrent connections. BTW Open Onload is an open source implementation.  Writing a network stack is a serious undertaking.  In a previous life I wrote a network probe and had to reassemble TCP streams and kept getting tripped up by edge cases.  It is a great exercise in data structures and lock-free programming.  If you need very high-end performance I’d talk to the Solarflare or Mellanox guys before writing my own. There are some errors and omissions in this talk.  For example, his range of ephemeral ports is not quite right, and atomic operations are only 15 cycles on Sandy Bridge when hitting local cache.  A big issue for me is when he defined C10M he did not mention the TIME_WAIT issue with closing connections.  Creating and destroying 1 million connections per second is a major issue.  A protocol like HTTP is very broken in that the server closes the socket and therefore has to retain the TCB until the specified timeout occurs to ensure no older packet is delivered to a new socket connection.

    (tags: mechanical-sympathy hardware scaling c10m tcp http scalability snabb-switch martin-thompson)

  • ec2-consistent-snapshot

    This program creates an EBS snapshot for an Amazon EC2 EBS volume. To help ensure consistent data in the snapshot, it tries to flush and freeze the filesystem(s) first as well as flushing and locking the database, if applicable. Filesystems can be frozen during the snapshot. Prior to Linux kernel 2.6.29, XFS must be used for freezing support. While frozen, a filesystem will be consistent on disk and all writes will block. There are a number of timeouts to reduce the risk of interfering with the normal database operation while improving the chances of getting a consistent snapshot. If you have multiple EBS volumes in a RAID configuration, you can specify all of the volume ids on the command line and it will create snapshots for each while the filesystem and database are locked. Note that it is your responsibility to keep track of the resulting snapshot ids and to figure out how to put these back together when you need to restore the RAID setup.
    Handy!

    (tags: ubuntu ec2 aws linux ebs snapshots ops tools alestic)

  • Measuring & Optimizing I/O Performance

    Another good writeup on iostat and EBS, from Ilya Grigorik

    (tags: io optimization sysadmin performance iostat ebs aws ops)

  • AWS forum post on interpreting iostat output for EBS

    Great post from AndrewC@EBS on interpreting iostat output on EBS volumes — from 2009, but still looks reasonable enough

    (tags: iostat ebs disks hardware aws ops)

  • Operations is Dead, but Please Don’t Replace it with DevOps

    This is so damn spot on.

    Functional silos (and a standalone DevOps team is a great example of one) decouple actions from responsibility. Functional silos allow people to ignore, or at least feel disconnected from, the consequences of their actions. DevOps is a cultural change that encourages, rewards and exposes people taking responsibility for what they do, and what is expected from them. As Werner Vogels from Amazon Web Services says, “you build it, you run it”. So a “DevOps team” is a risky and ultimately doomed strategy. Sure there are some technical roles, specifically related to the enablement of DevOps as an approach and these roles and tools need to be filled and built. Self service platforms, collaboration and communication systems, tool chains for testing, deployment and operations are all necessary. Sure someone needs to deliver on that stuff. But those are specific technical deliverables and not DevOps. DevOps is about people, communication and collaboration. Organizations ignore that at their peril.

    (tags: devops teams work ops silos collaboration organisations)

Links for 2013-05-14

Published May 14, 2013

Links for 2013-05-03

Published May 3, 2013

Links for 2013-05-02

Published May 2, 2013

  • Hey Judy, don’t make it bad

    Github get good results using Judy arrays to replace a Ruby hash. However: the whole blog post is a bit dodgy to me. It feels like there are much better ways to fix the problem: 1. the big one: don’t do GC-heavy activity in the front-end web servers. Split that language-classification code into a separate service. Write its results to a cache and don’t re-query needlessly. 2. why isn’t this benchmarked against a C/C++ hash? it’s only 36000 entries, loaded once at startup. lookups against that should be blisteringly fast even with the basic data structures, and that would also be outside the Ruby heap so avoid the GC overhead. Feels like the use of a Judy array was a “because I want to” decision. 3. personally, I’d have preferred they spend time fixing their uptime problems…. See also https://news.ycombinator.com/item?id=5639013 for more kvetching.

    (tags: ruby github gc judy-arrays linguist hashes data-structures)

Links for 2013-05-01

Published May 1, 2013

  • Kanban for MDN development

    Mozilla’s experience with Kanban. We’ve had good results in Amazon, too. good intro links in this post — might start talking about it in Swrve…

    (tags: kanban scheduling team agile mozilla)

  • Secret Bitcoin mining code added to game sparks outrage

    Thunberg’s admission that [the E-Sports Entertainment Association client software] ran Bitcoin-mining software without explicit user consent is startling. Aside from potentially opening the company up to huge legal liability, the move is likely to engender distrust among some of the company’s most loyal fans. The nonchalance of some of Thunberg’s comments may only add insult to the betrayal many users are likely to feel. “But for the record, I told jag he shouldn’t be lazy and run the miner in a separate process,” he wrote in a post, referring to one of his software engineers with the screen name Jaguar, who didn’t take steps to conceal the Bitcoin miner. “Rookie move.” In the later post he wrote: “100% of the funds are going into the s14 prize pot, so at the very least your melted gpus contributed to a good cause.”

    (tags: bitcoin abuse games malware esea gpus)

Links for 2013-04-29

Published April 29, 2013

  • Lectures in Advanced Data Structures (6.851)

    Good lecture notes on the current state of the art in data structure research.

    Data structures play a central role in modern computer science. You interact with data structures even more often than with algorithms (think Google, your mail server, and even your network routers). In addition, data structures are essential building blocks in obtaining efficient algorithms. This course covers major results and current directions of research in data structures: TIME TRAVEL We can remember the past efficiently (a technique called persistence), but in general it’s difficult to change the past and see the outcomes on the present (retroactivity). So alas, Back To The Future isn’t really possible. GEOMETRY When data has more than one dimension (e.g. maps, database tables). DYNAMIC OPTIMALITY Is there one binary search tree that’s as good as all others? We still don’t know, but we’re close. MEMORY HIERARCHY Real computers have multiple levels of caches. We can optimize the number of cache misses, often without even knowing the size of the cache. HASHING Hashing is the most used data structure in computer science. And it’s still an active area of research. INTEGERS Logarithmic time is too easy. By careful analysis of the information you’re dealing with, you can often reduce the operation times substantially, sometimes even to constant. We will also cover lower bounds that illustrate when this is not possible. DYNAMIC GRAPHS A network link went down, or you just added or deleted a friend in a social network. We can still maintain essential information about the connectivity as it changes. STRINGS Searching for phrases in giant text (think Google or DNA). SUCCINCT Most “linear size” data structures you know are much larger than they need to be, often by an order of magnitude. Some data structures require almost no space beyond the raw data but are still fast (think heaps, but much cooler).
    (via Tim Freeman)

    (tags: data-structures lectures mit video data algorithms coding csail strings integers hashing sorting bst memory)

  • Older Is Wiser: Study Shows Software Developers’ Skills Improve Over Time

    At least in terms of StackOverflow rep:

    For the first part of the study, the researchers compared the age of users with their reputation scores. They found that an individual’s reputation increases with age, at least into a user’s 40s. There wasn’t enough data to draw meaningful conclusions for older programmers. The researchers then looked at the number of different subjects that users asked and answered questions about, which reflects the breadth of their programming interests. The researchers found that there is a sharp decline in the number of subjects users weighed in on between the ages of 15 and 30 – but that the range of subjects increased steadily through the programmers’ 30s and into their early 50s. Finally, the researchers evaluated the knowledge of older programmers (ages 37 and older) compared to younger programmers (younger than 37) in regard to relatively recent technologies – meaning technologies that have been around for less than 10 years. For two smartphone operating systems, iOS and Windows Phone 7, the veteran programmers had a significant edge in knowledge over their younger counterparts. For every other technology, from Django to Silverlight, there was no statistically significant difference between older and younger programmers. “The data doesn’t support the bias against older programmers – if anything, just the opposite,” Murphy-Hill says.
    Damn right ;)

    (tags: coding age studies software work stack-overflow ncsu knowledge skills life)

  • TestDouble

    Test Double is a generic term for any case where you replace a production object for testing purposes. There are various kinds of double that Gerard lists: Dummy objects are passed around but never actually used. Usually they are just used to fill parameter lists. Fake objects actually have working implementations, but usually take some shortcut which makes them not suitable for production (an InMemoryTestDatabase is a good example). Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what’s programmed in for the test. Spies are stubs that also record some information based on how they were called. One form of this might be an email service that records how many messages it was sent. Mocks are pre-programmed with expectations which form a specification of the calls they are expected to receive. They can throw an exception if they receive a call they don’t expect and are checked during verification to ensure they got all the calls they were expecting.

    (tags: test-doubles naming patterns tdd testing mocking tests martin-fowler)

Links for 2013-04-28

Published April 28, 2013

  • Limerick-Tralee walking/cycling route blocked by farmers

    Oh for god’s sake. I know a few people who’ve made a trip to Mayo explicitly because the Greenway was there to visit. This is shocking, backwards stuff:

    The success of [Mayo’s] Great Western Greenway [trail] has overtaken that of others, such as the Great Southern Trail group, which has been working hard to install a walking and cycling route on sections of the former Limerick-Tralee railway line. On February 2nd, to mark the 50th anniversary of its closure, about 150 members and supporters of the Great Southern Trail set out from the old railway station at Abbeyfeale, Co Limerick, along the most recently developed section to cross the Kerry county boundary. The trailers were greeted by a barricade on the border, manned by more than 30 farmers, including the Listowel Fine Gael town councillor Denis Stack. A stand-off continued for three hours, with the Garda mediating in vain. The farmers were trying to lay claim to the land occupied by the disused railway line, even though Minister for Transport Leo Varadkar had made it clear that CIÉ “is the owner of the property [and] will object to any application by others to register these lands”.
    (via Rossa McMahon)

    (tags: via:rossamcmahon cycling walking hiking trails ireland kerry limerick listowel denis-stack cie)

  • jq

    like sed for JSON data – you can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you play with text. [it] is written in portable C, and it has zero runtime dependencies. You can download a single binary, scp it to a far away machine, and expect it to work.
    Nice tool. Needs to get into the Debian/Ubuntu apt repos pronto ;)

    (tags: jq tools cli via:peakscale json coding data sed unix)