It’s been a while since I wrote a long-form blog post here, but this post on the Swrve Engineering blog is worth a read; it describes how we use SSD caching on our EC2 instances to greatly improve EBS throughput.
Author Archives: Justin
A common error when using the Metrics library is to record Timer metrics on things like API calls, using the default settings, then to publish those to a time-series store like Graphite. Here’s why this is a problem. By default, a Timer uses an Exponentially Decaying Reservoir. The docs say: ‘A histogram with an exponentially […]
Man sues RMV after driver’s license mistakenly revoked by automated anti-terror false positive: John H. Gass hadn’t had a traffic ticket in years, so the Natick resident was surprised this spring when he received a letter from the Massachusetts Registry of Motor Vehicles informing him to cease driving because his license had been revoked. […] […]
(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 […]
So, after just over 3 and a half years, I’m leaving Amazon. It’s been great fun — I can honestly say, even with my code being used by hundreds of millions of users in SpamAssassin and elsewhere, I hadn’t really had to come to grips with the distributed systems problems that an Amazon-scale service involves. […]
Here’s a letter to the editor of The Times, dated 1st June 1864: TO THE EDITOR OF THE TIMES. Sir, — On my arrival home late yesterday evening a “telegram,” by “London District Telegraph,” addressed in full to me, was put into my hands. It was as follows :– “Messrs. Gabriel, dentists, 27, Harley-street, Cavendish-square. […]
Reminder to Dublin-based readers — next week, Amazon (my employers) will be putting on Under the Hood at Amazon, billed as ‘A night of Beer, Pizza and Cloud Computing for Software Developers’. I’ll be speaking at it. It’s partially a recruiting event, but even if you’re not looking for a new job, please come along. […]
This sounds very cool! Nice one, hackerspace ppl. Ireland’s Hackerspaces and Makerspaces (091 Labs – Galway, Belfast Hackerspace, MilkLabs – Limerick, Nexus Cork and TOG – Dublin) have been asked to build and man a temporary hackerspace during the MindField – International Festival of Ideas (http://www.mindfield.ie/). MindField will take place over the weekend of 29 […]
I’m uncomfortable voting for David Norris for President. Here’s why. In November last year, he was a key voice in a Senate debate on the topic of “Protection of Intellectual Property Rights”, where he quoted heavily from the flawed judgement by Mr. Justice Peter Charleton in the Warner, Universal, Sony BMG and EMI vs UPC […]
It’s pretty common for apps to require “configuration” — external files which can contain settings to customise their behaviour. Ideally, apps shouldn’t require configuration, and this is always a good aim. But in some situations, it’s unavoidable. In the abstract, it may seem attractive to use a fully-fledged programming language as the language to express […]
If you visit the Irish Times at all frequently, you’ll probably have noticed a nifty “wisdom of crowds” feature in the right sidebar: the list of “most read” articles. It’s quite good, since they’re often very interesting articles. Unfortunately, there’s no RSS feed for this feature. Well, now there is: Irish Times Most Read RSS […]
Facing yet another day of being snowed in, with Dublin’s icy roads and footpaths driving us all stir crazy, I came up with this: More pics, vid — fun!
The Dublin Science Gallery Greeting Cards are excellent! Get ’em here, or pick up one of the great gadgets and gifts they have in stock. (disclaimer: I am mates with the designer and the guy who runs the shop — but I still think they’re great work, regardless ;)
So, after I posted this post about Aslan’s imaginary illegal downloads, someone on Twitter linked to this comment by Senator Paschal Mooney (Fianna Fail), in the Seanad the next day, repeating the incorrect Aslan factoid: Sen. Paschal Mooney (Fianna Fail): There is a perception that the big five record companies, all international companies, have been […]
Submitted via email to their letters page. This may be a bit too long for the format, but hey. Enjoy. Madam, — Commentary in this paper and elsewhere has given the impression that Mr. Justice Charleton’s judgement on the EMI v. UPC case was a poor result for EMI and the other record companies represented. […]
Oh dear. Quoting Mr Justice Charleton’s judgement in favour of UPC vs. EMI, Sony, et al: ‘This scourge of internet piracy strongly affects Irish musicians, most of whom pay tax in Ireland. ‘Aslan’ is a distinguished Irish group which has a loyal fan base; but not all of them believe in paying for music.Previous sales […]
This page has been floating around in links over the past couple of weeks, as a collection of test cases to compare e-mail address validating regular expressions. However, watch out: it’s wrong. RFC822/2822 defines an email address with a bare IP address domain part as using: domain-literal = [CFWS] “[” *([FWS] dcontent) [FWS] “]” [CFWS] […]
Mr. Justice Peter Charleton, in the course of his judgement on EMI Records & Ors -v- Eircom Ltd is quoted as having said the following: ‘ There is fundamental right to copyright in Irish Law. This has existed as part of Irish legal tradition since the time of Saint Colmcille. He is often quoted for […]
Guinness‘ latest product, Guinness Black Lager, gets a panning in the Irish Times today. I’m not a fan of Guinness. It’s a good beer, but monotonous when it’s the only thing available. This, from the old Dublin Brewing Company website, makes some interesting allegations as to why that may be the case: In 1996 the […]
SpamAssassin 3.3.1 went out last Friday. The main change here is the inclusion of Spamhaus’ new URIBL list, the DBL, as the URIBL_DBL_SPAM rule. Download page for source tarballs etc. Here’s RPM packages from Warren.
Just heading this one off before it gets too much further… A couple of weeks ago, a researcher found a bug in the spamass-milter project, an open-source milter to integrate SpamAssassin filtering into an MTA. Here’s the exploit details. This H-Online story covered it: Security vulnerability in SpamAssassin filter module The SpamAssassin Milter plug-in which […]
Happy new year! Or maybe not. Doh. Over a year ago, Lee Maguire noticed that a contributed SpamAssassin rule, FH_DATE_PAST_20XX, was naively written — simply to match any date in the year 2010 or later — and would start to false-positive on all mail in 14 months. We made the trivial fix to avoid this […]
For the past 2 years or so, I’ve been using GMail to handle my main mail feed for jmason.org. I’m an absolute convert to its “river of threads”/search-based workflow. Since starting at Amazon, I’ve had to start dealing with a heavy volume of work mail. Previously jobs have either had low mail volumes, or used […]
Irish iPhone users — you may find this useful. I’ve written a web scraper which takes a couple of the more useful pages on Met Eireann’s website — the regional forecast and the rainfall radar page — and reformats them in an iPhone-optimised style. Enjoy: iPhone-Optimised Weather Forecast for Ulster iPhone-Optimised Weather Forecast for Munster […]
Regarding Google Wave’s similarity to Lotus Notes, which is a meme I’ve heard from several angles — David Jones hits the nail on the head: Well, I used Notes from 1994 to 1999. It did have a database backend for e-mail and a rich collaborative editing model. But it didn’t have realtime shared editing, or […]
Colm’s “n+1” post reminded me that I’d forgotten to write about this. On July 27th, I started at Amazon, in a new Dublin-based software dev team working on infrastructure automation. It’s now (just over) a month later, and I’m enjoying it immensely. Needless to say, this company does some very interesting web-scale technology, and getting […]
I woke up this morning to hear speculation on RTE Radio as to how Eircom’s DDOS woes were possibly being caused by the Russian mob, of all things. This absurd speculation is not helped by lines in statements like this: ‘The company blamed the problems on “an unusual and irregular volume of internet traffic” directed […]
Found here: On Wednesday 20 May 2009, speaking at a parliamentary Justice Committee debating his new blasphemy law, Dermot Ahern joked that people were making blasphemous comments about him, and he compared his own purity to that of the baby Jesus. So we have a Justice Minister joking about himself being blasphemed, at a parliamentary […]
A while back a friend of mine mailed us all with this classic of overweening health-and-safety bureaucrats gone wild: The company are now installing wallpaper on our PCs with their 5 golden safety rules: Always hold the handrail Always reverse park Assess Risks Accept Challenges Wear PPE [Personal Protective Equipment] gear We also have to […]
Hey Gravatar. When you auto-generate an avatar image, like you did with the one to right, could you do me a favour and omit the bits that look like swastikas? kthxbai!
Last year, I blogged about Full-Text RSS, a utility to convert those useless “partial-text” RSS/Atom feeds into the real, full-story-inline deal. The only downside is that the author felt it necessary to withhold the source, saying: Still, I wouldn’t want to offer a feature that middlemen can resell at the expense of bloggers. So while […]
For years now, I’ve been collecting bookmarks at delicious.com/jm — nearly 7000 of them by now. I’ve been scrupulous about tagging and describing each one, so they’re eminently searchable, too. I’ve frequently found this to be a very useful personal reference resource. I was quite pleased to come across the Delicious Search Results on Google […]
For the upcoming release of Apache SpamAssassin, we’re considering dropping support for perl 5.6.x interpreters. Perl 5.6.0 is 9 years old, and the most recent maintainance release, 5.6.2, dates back to November 2003. The current 5.x release branch is 5.10, so we’re still sticking with a “support the release branch before the current one” policy […]
The same friend who was victim to the BoI user-data leak last year has also fallen victim to the Bord Gais leak! how’s that for luck. Here’s the letter he received: Page 1 At least they make much more convincing worried noises.
Watching television last night, I couldn’t fail to take notice of this new IBM ad: ‘For the first time in history, more people live in cities than anywhere else, which means cities have to get smarter.’ […] ‘Paris has smart healthcare; smart traffic systems in Brisbane keep traffic moving; Galway has smart water’. Jaw-dropping. That […]