Thursday, March 11, 2010
Trio Sequencing
Check out this article from NYTimes on trio sequencing. My prediction is that within a generation, sequencing your immediate family will be a routine luxury.
Wednesday, March 10, 2010
Grace Triflex: Not on my roof!
It's time to replace our roof. I've talked to three different roofing contractors after finding them on Angie's List. Two of them understand the issues that my 1930s New England bungalow, with its unvented roof, presents. The other one was trying to push a bunch of bad product onto my roof.
If I were building a new roof that was properly vented and I needed to dry it in for a month in Wisconsin in January, I'd probably want to use something like Grace Triflex 30 as an underlayment. It's water repellent, strong, doesn't tear, and won't degrade from UV light (for a while at least). But with a permeability of about 0.5, it also doesn't breathe worth a damn when compared to traditional roofing felt/tar paper. In new construction roofing with proper ventilation, this doesn't matter. In an 80 year old house with an unvented roof and an improved attic with knee walls and all kinds of loose, leaky construction, this is a Very Bad Thing To Do, especially when you slather Grace Ice and Water Shield all over other parts of the roof.
The problem is that unvented roofs need to breathe water vapor out the roof. Ice and water shield doesn't pass water vapor. Triflex sort of does, but not very well. My suspicion, after doing a bit of research, is that putting this stuff on an old roof with poor roof ventilation will greatly accelerate dry rot. It's a great product applied in the wrong situation, like using peanut butter when the situation calls for Astroglide.
Check out some research on this topic from RCI, Incorporated:
Overview of Underlayments
Overview of Underlayments Part 2
Roofing Upgrades Gone Wrong
Interestingly, when I made this claim to the roof salesman, he said "This stuff hasn't been around long enough to demonstrate that it causes dry rot." The guy was doing a hard sell. It was weird to have a roof salesman do a hard sell. It's a roof--not a car. Of all the contractors I've talked to over the years, this was the first one with a real hardnose sales pitch, which made me suspicious. But his comment made me even less likely to use the product. It hasn't been around long enough to prove itself. Roofing felt and tar paper, while imperfect, are well understood technologies whose upsides and downsides can be worked around. I'm sure Triflex is a great product for the right house. But I doubt it's the right thing for older, unvented roofs.
If I were building a new roof that was properly vented and I needed to dry it in for a month in Wisconsin in January, I'd probably want to use something like Grace Triflex 30 as an underlayment. It's water repellent, strong, doesn't tear, and won't degrade from UV light (for a while at least). But with a permeability of about 0.5, it also doesn't breathe worth a damn when compared to traditional roofing felt/tar paper. In new construction roofing with proper ventilation, this doesn't matter. In an 80 year old house with an unvented roof and an improved attic with knee walls and all kinds of loose, leaky construction, this is a Very Bad Thing To Do, especially when you slather Grace Ice and Water Shield all over other parts of the roof.
The problem is that unvented roofs need to breathe water vapor out the roof. Ice and water shield doesn't pass water vapor. Triflex sort of does, but not very well. My suspicion, after doing a bit of research, is that putting this stuff on an old roof with poor roof ventilation will greatly accelerate dry rot. It's a great product applied in the wrong situation, like using peanut butter when the situation calls for Astroglide.
Check out some research on this topic from RCI, Incorporated:
Overview of Underlayments
Overview of Underlayments Part 2
Roofing Upgrades Gone Wrong
Interestingly, when I made this claim to the roof salesman, he said "This stuff hasn't been around long enough to demonstrate that it causes dry rot." The guy was doing a hard sell. It was weird to have a roof salesman do a hard sell. It's a roof--not a car. Of all the contractors I've talked to over the years, this was the first one with a real hardnose sales pitch, which made me suspicious. But his comment made me even less likely to use the product. It hasn't been around long enough to prove itself. Roofing felt and tar paper, while imperfect, are well understood technologies whose upsides and downsides can be worked around. I'm sure Triflex is a great product for the right house. But I doubt it's the right thing for older, unvented roofs.
Sunday, February 21, 2010
Some Recent Coffee Experiences
After the birth of my 2nd child, my wife thankfully encouraged me to go grab a shot at Barismo in Arlington Center. Lord knows with a newborn you need all the uppers you can get. Barismo was totally mind-blowing. The best shot of espresso I have ever had. On the day that I was there they were serving Koke. I went back the day after and had a 50/50 Doppelganger. Both were excellent, fully of crema. The Doppelganger had a downright raspberry flavor to it that I've never experienced with espresso. The Doppelganger was the first shot of espresso I've ever had that required absolutely no sugar. I bought some of the Koke and when I had it at home with my Mazzer Mini and Pavoni, it was delightful as well. Barismo is an experience unto itself, and it doesn't hide the fact that if you want really amazing espresso, coffee, or tea, you have to wait for it. Each shot requires some patience, but it's totally worth it. If the line is out the door, come back some other time. But if you hit the place in the middle of a slow weekday, you're in for a treat.
My mother in law--a huge fan of coffee--arrived a few days later to help take care of our son and as a treat I took her to see George Howell's new-ish coffee operation in Ashland, MA. We didn't make an appointment and truth be told I wasn't sure if the place was going to be corporate HQ offices, a giant loading dock, or an actual cafe. We just sort of stumbled into the place, walked into the back room and met George and his lovely daughter. George was kind enough to take me, my mother in law, and my 2.5 year old daughter on a quick tour of the operation, showing us a bit of R&D, bean packaging, roasting, and tasting. It was awesome. And his daughter pulled me a shot that rivaled Barismo's. It's clear that George loves coffee and all of the details that go into a relatively high throughput (at least compared to Barismo) roasting operation. I was a kid when George first opened coffee connection and as a teenager I lamented the dropoff in quality when the Coffee Connection was dragged asunder by Charbucks. So I'm very excited to see George Howell back at it, delivering us from the evils of Starbucks' brand of super dark, burned, thin coffee. I usually buy George's beans from Whole Foods, but I notice that sometimes the beans aren't terribly fresh. Mail order from GHH is pretty speedy and the beans are always very fresh.
Update: Some great espresso beans from George Howell: Kaguimoini, Sorento, and Gingerbread. All are terrific. The Kaguimoini is very complex. The Sorento is more caramel-y and chocolaty.
My mother in law--a huge fan of coffee--arrived a few days later to help take care of our son and as a treat I took her to see George Howell's new-ish coffee operation in Ashland, MA. We didn't make an appointment and truth be told I wasn't sure if the place was going to be corporate HQ offices, a giant loading dock, or an actual cafe. We just sort of stumbled into the place, walked into the back room and met George and his lovely daughter. George was kind enough to take me, my mother in law, and my 2.5 year old daughter on a quick tour of the operation, showing us a bit of R&D, bean packaging, roasting, and tasting. It was awesome. And his daughter pulled me a shot that rivaled Barismo's. It's clear that George loves coffee and all of the details that go into a relatively high throughput (at least compared to Barismo) roasting operation. I was a kid when George first opened coffee connection and as a teenager I lamented the dropoff in quality when the Coffee Connection was dragged asunder by Charbucks. So I'm very excited to see George Howell back at it, delivering us from the evils of Starbucks' brand of super dark, burned, thin coffee. I usually buy George's beans from Whole Foods, but I notice that sometimes the beans aren't terribly fresh. Mail order from GHH is pretty speedy and the beans are always very fresh.
Update: Some great espresso beans from George Howell: Kaguimoini, Sorento, and Gingerbread. All are terrific. The Kaguimoini is very complex. The Sorento is more caramel-y and chocolaty.
Wednesday, February 3, 2010
Hibernate/JPA confuses "legacy" with "high throughput", "scalable", and "complex"
I like Hibernate/JPA for dead-simple inserts and update. I detest it for queries. I also detest how the Hibernate documentation totally misuses the term "legacy". When I hear the term "legacy", I think "old and dumb". But on planet Hibernate, "legacy" means "Any application which operates on a piddly amount of data and doesn't buy into our myopic, java-centric view of the cosmos in which a relational database is just a pain-in-the-ass file system whose performance and data integrity issues exist only to perpetuate the hiring of very expensive DBAs".
For example, Hibernate says it doesn't support trigger-driven sequence creation because that's a "legacy" kind of a thing. What if my database is accessed both by Scala, Ruby, Perl, and Java? I'd like to encode some core business rules directly in the database so I don't have to duplicate logic in different languages. I don't call that "legacy". I call it "reality".
Hibernate thinks that compound unique keys are indicative of a "legacy" database. There are perfectly good reasons--from a (gasp!) data modeling perspective--to use complex unique keys and dispense with primary keys. Having to introduce new artificial primary keys into all my tables to make life easier for the object layer is something I am now more or less required to do so as not to infuriate application developers. But there is a real cost to the data model: the data model is forced to violate DRY. The data model has to maintain two redundant definitions of uniqueness: one that is natural and one that is imposed by Hibernate. Hibernate claims that having a foreign key refer to a unique key of the associated table rather than the primary key is "complicated and confusing". This is bullshit.
Hibernate thinks that only "legacy" tables have lots of columns. In reality, it's often very useful to make really fat tables to accomodate what would otherwise be complex, possibly inefficient multi-table queries. I've made fat tables before and I'll make them again. It's not legacy, it's reality.
Hibernate thinks that everyone should have "fewer tables than classes", and then claims that storing some attributes in a secondary table (hello
My needs aren't legacy needs. These are the needs of reality.
For example, Hibernate says it doesn't support trigger-driven sequence creation because that's a "legacy" kind of a thing. What if my database is accessed both by Scala, Ruby, Perl, and Java? I'd like to encode some core business rules directly in the database so I don't have to duplicate logic in different languages. I don't call that "legacy". I call it "reality".
Hibernate thinks that compound unique keys are indicative of a "legacy" database. There are perfectly good reasons--from a (gasp!) data modeling perspective--to use complex unique keys and dispense with primary keys. Having to introduce new artificial primary keys into all my tables to make life easier for the object layer is something I am now more or less required to do so as not to infuriate application developers. But there is a real cost to the data model: the data model is forced to violate DRY. The data model has to maintain two redundant definitions of uniqueness: one that is natural and one that is imposed by Hibernate. Hibernate claims that having a foreign key refer to a unique key of the associated table rather than the primary key is "complicated and confusing". This is bullshit.
Hibernate thinks that only "legacy" tables have lots of columns. In reality, it's often very useful to make really fat tables to accomodate what would otherwise be complex, possibly inefficient multi-table queries. I've made fat tables before and I'll make them again. It's not legacy, it's reality.
Hibernate thinks that everyone should have "fewer tables than classes", and then claims that storing some attributes in a secondary table (hello
@Secondary annotation) is really only for...you guessed it..."legacy" databases. Hold the phone. What if I have some bit of data that is part of an object but needs database-level security? For example, if I have a patient table and I want to expose access to social security numbers, perhaps I'd like to put the social security numbers in a separate table, or in a separate schema, and have the database manage the security of this table slightly differently? What if I have some huge freakin' columns that map to a particular subclass of an object, but I'd like to keep them stored separately for query performance? What if these columns are extremely rarely used? I don't want to risk pulling them all into memory (which I can control by FetchType.EAGER). I want to manage the storage for these data differently. Maybe the data is so large that I need to partition the backing tables. Hibernate seems to be saying that these situations are for those stupid old "legacy" applications. Just let your object model define the data model! What could possibly go wrong? My needs aren't legacy needs. These are the needs of reality.
Tuesday, January 26, 2010
Installing artifact: [your file name here] (Input/output error), Result too large, and disk errors.
From time to time I was getting the "[INFO] Error installing artifact: [your file name here] (Input/output error)" error message from Maven. It started happening at seemingly random points during maven builds but it seemed to favor bonking on large zip/war files. Then I started seeing "Result too large" errors. At that point I made sure I had a clean backup on the sever, rebooted, and crossed my fingers.
My machine failed to boot. It just sat there with the black and white whirly thingy Mac startup screen.
I chalked the problem up to I/O gremlins from the planet Zorng, so I called my IT group, who dropped the Disk Utility and Disk Warrior bombs on my SSD. After they were done, I had to manually refresh my Spotlight index, which took a few hours, but then things were back to normal. One other thing I learned: don't let IDEA attempt to re-index files until *AFTER* you've let Spotlight update its own index.
My machine failed to boot. It just sat there with the black and white whirly thingy Mac startup screen.
I chalked the problem up to I/O gremlins from the planet Zorng, so I called my IT group, who dropped the Disk Utility and Disk Warrior bombs on my SSD. After they were done, I had to manually refresh my Spotlight index, which took a few hours, but then things were back to normal. One other thing I learned: don't let IDEA attempt to re-index files until *AFTER* you've let Spotlight update its own index.
Saturday, January 23, 2010
Ice dam prevention time!
The neighbors must think I'm a bit nuts for how often I rake snow off the roof. At least that's what I thought until I saw the guy across the street actually climb up on his roof in January with a shovel and start shoveling it off. I use a very long roof rake to clear snow and I stand on the ground. Getting up on an icy roof in January in New England strikes me as suicidal, but anyhoo...
When the weather is super cold, there's really no point in clearing the snow off the roof because it forms a nice, solid icy barrier. This is actually a handy type of insulation...but when things start to thaw, that's when the ice dam beast can appear. By that time, it's impossible to clear the snow off the roof because it has hardened to a solid icy mass. Even if you did chip away at it, you'd likely start hacking off roof shingles along with the roof, throwing out the baby with the bathwater as they say. So you gotta rake the snow off the roof when it's nice and fluffy. Otherwise, you're screwed come spring or that ever unpredictable February deluge of 3" of rain and 60 degrees (followed by another month of temperatures in the teens of course--welcome to New England).
So my advice is: roof rake early and often. Gently bash ice and snow out of the gutters whenever possible. You'll get no payoff (other than huge triceps) until it starts raining when you have a foot of snow on your roof. If you have a uniformly steep roof, you can probably safely ignore my advice. But if you have a very bungalow-y roof, with lots of changes in pitch and some relatively flat roofs, go get a roof rake.
We have a few feet of snow on the ground and the forecast calls for about 2" of heavy rain in the next few days. Here's when I get a bit bonkers, trying to clear yet more snow off the roof, running around outside, digging the downspouts out of the snow and trying to dig little snow trenches so that the roof water will drain away from the house.
It's great exercise. Kettlebells are a good workout for snow shoveling and roof raking. I'm hoping the effort pays off and we don't see any rain in the basement.
When the weather is super cold, there's really no point in clearing the snow off the roof because it forms a nice, solid icy barrier. This is actually a handy type of insulation...but when things start to thaw, that's when the ice dam beast can appear. By that time, it's impossible to clear the snow off the roof because it has hardened to a solid icy mass. Even if you did chip away at it, you'd likely start hacking off roof shingles along with the roof, throwing out the baby with the bathwater as they say. So you gotta rake the snow off the roof when it's nice and fluffy. Otherwise, you're screwed come spring or that ever unpredictable February deluge of 3" of rain and 60 degrees (followed by another month of temperatures in the teens of course--welcome to New England).
So my advice is: roof rake early and often. Gently bash ice and snow out of the gutters whenever possible. You'll get no payoff (other than huge triceps) until it starts raining when you have a foot of snow on your roof. If you have a uniformly steep roof, you can probably safely ignore my advice. But if you have a very bungalow-y roof, with lots of changes in pitch and some relatively flat roofs, go get a roof rake.
We have a few feet of snow on the ground and the forecast calls for about 2" of heavy rain in the next few days. Here's when I get a bit bonkers, trying to clear yet more snow off the roof, running around outside, digging the downspouts out of the snow and trying to dig little snow trenches so that the roof water will drain away from the house.
It's great exercise. Kettlebells are a good workout for snow shoveling and roof raking. I'm hoping the effort pays off and we don't see any rain in the basement.
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