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Ruby on Rails 2.0 is Done
Posted by
CmdrTaco
on Sat Dec 08, 2007 01:26 PM
from the i-miss-perl dept.
from the i-miss-perl dept.
Jamie noted that ruby on rails 2.0 is done. In addition to upgrade and installation instructions, the article lists a number of the more interesting new features in the release which appears to be quite extensive.
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Rails Bigwig Rails on Rails Community 616 comments
Zed Shaw, creator of the popular Mongrel HTTP daemon / library, has decided it was high time to tear into the Ruby/Rails community for many different complaints that he has been collecting over the last few years. "Rails is a Ghetto" is Shaw's self-proclaimed exit strategy from the Rails community. "This is that rant. It is part of my grand exit strategy from the Ruby and Rails community. I don't want to be a 'Ruby guy' anymore, and will probably start getting into more Python, Factor, and Lua in the coming months. I've got about three or four more projects in the works that will use all of those and not much Ruby planned. This rant is full of stories about companies and people who've either pissed in my cheerios somehow or screwed over friends. I can back all of them up from emails, IRC chat logs, or with witnesses. Nothing in here is a lie unless it's really obviously a lie through exaggeration, and there's a lot of my opinion as well."
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ORM still broken? (Score:5, Informative)
RRN? (Score:5, Insightful)
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Re:ORM still broken? (Score:5, Insightful)
I don't even consider normalization taken to the extreme, to be a good thing. It's a trade off, just like everything else - what you gain by normalization, you might lose in the form of added application complexity, or perhaps even something else. Just because normalization is "good" according to ivory-tower database theory, doesn't mean that anything that isn't fully normalized is "bad" or "broken".
"Yes I know that a serial/autoincrementing key makes it easy for the app... it makes it a lot harder for the DBA in a lot of cases."
Can you explain what exactly it is that makes it a lot harder? (And isn't a DBA paid to do his job?)
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Re:ORM still broken? (Score:5, Insightful)
If you really, really, really, really need composite primary keys, you can still fallback to raw SQL queries in Rails.
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Re:ORM still broken? (Score:5, Interesting)
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Re:ORM still broken? (Score:5, Insightful)
If you do most of the logic in your stored procedures, it makes it easy to bolt on new features written in various languages. If you decide to have a perl script for a cron job, you just call the same stored procedures your ruby app is calling. If you want a windows front end for your admin staff, the windows app calls the same stored procedure too.
Once you bury the database logic in the application code, you have to rewrite it for every application. It is, in a way, a very evil form of copy & paste programming. Now every change in the database requires you to go into every single application and change something. Kinda like when you get slutty with your code and copy & paste it rather than abstract it out into a library.
And I'm aware stored procedures don't play nice if you are worried about cross-database issues because you sell the software. This only works when you get complete control over the application & database stack.
PS: MySQL stored procedures suck. Use a real database with a better stored procedure language.
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Re:ORM still broken? (Score:5, Insightful)
Borrowing from your SSN example, let's say that your client tells you the main way they identify customers is through the SSN, and you go by that, and then there's a case of identity theft and the customer's SSN number has to be changed? Now you've got potentially thousands of records with a bad primary key that you have to change (and mitigate constraint issues as well). What if privacy issues require the company dropping SSN's as an identifier, and now the company will be forbidden from asking customers their SSN's? You'll no longer be able to generate primary keys compatible with the same ones used before.
What truly separates a good DBA from a bad one is the good DBA's ability to anticipate change, design for change, insulate existing stuff from change, and basically save the client from any flaws in their own conceptual model (while making it look like they've followed the client's conceptual model to the letter). A bad DBA simply trusts whatever his client says and believes it to be correct and forever immutable.
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Re:ORM still broken? (Score:5, Insightful)
You are completely incorrect.
If your domain model describes the way an actor finds an entry is by Order# and Line#, that should in no way, shape, or form decree what your technical artifacts look like.
The correct thing to do in that case is to have a unique, opaque, identity key (numeric or guid, just so long as its unrelated to the record data, and has no additional meaning beyond the unique value of that record).
Then you can also add unique constraints or indexes to the composite key, and/or you can enforce that unique constraint in the application. Or both, for the smart ones.
But you need to have a unique way to identify the record THAT IS NOT SUBJECT TO CHANGE. In your example, you could re-order the lines, or one line could have been a mistake and you need to move it to a different order.
If you've used composite keys on order# and line#, then you've got alot of cleanup work to do after your change.
If you've used proper opaque identity keys, then you just change the data, and there are no side effects.
Since in that case your joins are also done on the identity keys, your relatinoships are stable even when you change order# or line#.
The SSN one is even worse. I can guarantee you that if you do that, someone will have the wrong SSN, and it will need to be changed in your data.
If you've used SSN as the primary key, then its a pain in the ass, and you have to do data integrity cleanup.
If you've used a proper opaque identity key, then you just change the SSN, and there are no side effects.
This is stuff you learn the first time you write an app as a junior developer without a mentor, and use SSN as a key. A year or two later you come to regret it, and the lesson is learned for a lifetime.
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Re:ORM still broken? (Score:4, Insightful)
If you're referring to DHH, then no, I'm not him. My stance isn't as extreme as his ("database is just a big hash") but I do agree with some of his points. Transactions = good. Foreign key constraints = good. Stored procedures = only use when absolutely necessary. Normalization = weight between pros and cons in application code complexity and data redundancies. Etc.
"The thing a lot of OSS developers seem to forget is that many applications are primarily for data processing with user interfaces thrown on top. I.e. Not every damn "web app" is a blog or wiki, where it's primary purpose is to be a web app."
Not every, but *a lot* of them are. Very often they're systems for displaying, storing and retrieving small to moderate amount of information (unless you're working on a really really big multi-million system).
"Fact is that, if Rails wants greater acceptance (and, yes, I realize it is already widely accepted -- I'm talking about continued growth), then it's going to need to support things like composite keys. Why? Because people use them, and the application may have come years before the web interface."
I don't think so. I'm pretty sure that people complain about composite primary keys because it's so easy to complain about. Most of them probably wouldn't consider using Rails even if it fixes all its "flaws". *
There was a time when I took all Internet complaints very seriously. I worked very, very, very hard to meet peoples' demand, and I did it for free. In the end, it didn't help. Whenever I publish a fix for one complaint, they complain about other things. It's an endless cycle. The complainers can never be satisfied no matter what I do.
For example, people complain about memory usage in Rails. I've developed a way to reduce the memory usage by 30% [plan99.net], and look - very few people are interested! The people interested in my work are extremely disproportional to the number of people complaining.
* But by fixing Rails "flaws", you've just made it worse. The reason why Rails is so great in the first place is because it's a very specialized framework. It's not trying to be the thing for everything, like J2EE. If you make it the thing for everything it'll be a lot more painful to work with. It's like saying that your television can't wash your clothes. While it's possible to make a television that does that, it would be a royal pain to make and to work with.
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Re:ORM still broken? (Score:5, Interesting)
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Re:ORM still broken? (Score:5, Insightful)
You're assuming that all composite primary keys use values that do change. That's highly unlikely, given the number of tables in the world filled with historical data. That said, I agree (for other reasons) that surrogate keys are much better.
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Re:ORM still broken? (Score:5, Funny)
What a relief... As a lisper and rubyist, I'm glad to hear that Python is going to die! Good riddance!
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Re:You don't have to use ActiveRecord (Score:5, Insightful)
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Re:You don't have to use ActiveRecord (Score:5, Funny)
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I don't understand the fuss. (Score:5, Interesting)
Re:I don't understand the fuss. (Score:5, Insightful)
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Re:I don't understand the fuss. (Score:5, Interesting)
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Re:I don't understand the fuss. (Score:5, Insightful)
Some things to read about and try within Rails:
* ActiveRecord's ability to introspect the DB schema at runtime. e.g. autocreating the method to allow: User.find_by_name('Joe')
* ActiveRecord's magic-fields, e.g. created_at/updated_at
* the ActiveRecord associations, and the easy DB queries that come with them, e.g. @user.posts.find(:all,
* the scope_out plugin, which provides some nice additions to 'with_scope'. e.g. in the Post model you could do scope_out
@user.posts.pending
* ActiveRecord callbacks and the controller before/after filters
* the RESTful routing and easy links that come with it, e.g. link_to(@user.name, @user) will create a hyperlink to the correct URL for that user record's 'show' page
* the form/field helpers which also integrate with the routing, so you can now do just form_for(@user) - it will create a proper form tag for hitting either the create or update method for that @user, depending on whether the record has already been saved to the database - the form_for/fields_for block syntax is also very powerful, especially when you add your own form helper methods
* all the convenience methods provided by active_support, like 5.minutes or 1.month.ago
* Ruby itself - Ruby is simply a joy to code in. even if I were going to dump Rails, I would now strongly prefer to find a new Ruby framework(like Merb) than using another language
I'd strongly urge you to pick one or more of the PHP MVC frameworks to look at while you read about Rails. Most of them are copies or at least inspired off Rails to some degree, so they often use similar conventions. You'll see the difference between what's possible in PHP and Ruby - PHP doesn't come out looking too good at the end
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Re:I don't understand the fuss. (Score:4, Interesting)
Uhm no I don't. I've programmed in Perl far longer than I've programmed in Ruby. I only started with Ruby about 2 years ago. I have experience with mod_perl and stuff like Template Toolkit. I have experience with Python. And Ruby on Rails *still* beats everything else I've used.
It isn't just Ruby, it's also Rails. It's the entire package. Rails is not just any framework, it's an entire design philosophy. It's opinionated software. It's Don't-Repeat-Yourself. It's REST. It's convention-over-configuration. All this stuff together makes me much, much more productive. Ruby on Rails actually makes web application programming more fun than desktop application programming.
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Sites Moved to Rails? (Score:5, Interesting)
Re:Sites Moved to Rails? (Score:5, Interesting)
We do millions of searches a day at yellowpages.com [yellowpages.com]. One day the order came down that the site was getting rewritten, on a hard deadline. In four months 125,000 lines of Java became 14,000 lines of Ruby, and yellowpages.com became (most likely) the second largest Rails site on the internet.
The site scaled just fine because we have a team that knows what they're doing. Above all, they did research. They wrote prototypes in other frameworks before settling on Rails. They benchmarked different features and decided what to turn off. Rather than create one giant dumb app, we have a web-tier app for interacting with the user, and a service tier for processing searches with our search cluster.
Anyone noticed people who say "Rails doesn't scale" never tried to scale it? I am part of a team that has successfully scaled to the second largest Rails site on the internet, and I will always tell people who say "Rails doesn't scale" that they have no idea what they're talking about.
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I guess they didn't fix the scalability issues (Score:5, Funny)
Otherwise, one might think that RoR doesn't scale.
Scaling matters if you're Digg. Are you Digg? (Score:5, Insightful)
I have a Rails site, my first (hopefully of many) for my small business, which plugs along at about 20 requests a second in tests. If I could saturate those 20 requests a second, I would quit my day job on the spot. Scaling? Eh, who cares.
(P.S. Day job is writing enterprise level crud apps for Japanese universities on the J2EE stack. They worry a bit about, e.g., getting hit with 8k users signing in simultaneously during class registration. You know what we do? Exactly what I'd do for a Rails app in the same situation ("don't do anything stupid like an n+1 queries loop, cache the important stuff, and buy enough hardware for the job"). Only difference in Rails is I have never wanted to poke my eye out with a spoon while writing it.
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Re:Scaling matters if you're Digg. Are you Digg? (Score:5, Insightful)
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Re:Scaling matters if you're Digg. Are you Digg? (Score:5, Interesting)
The upper limit I see with RoR/FCGI is around 2500 requests per sec, for a 'is the server alive' ping, that simply returns 'Yes'. Typical, results are in the ~100 requests per second range with moderate db access, and rendering to xml or html. 100 requests per second was enough to handle a 24 hour media buy on the frontpage of myspace for example (100,000k unique visitors-ish).
Moving your static assets off of your server and on to S3 or another CDN is obviously a big help here, so your server/bandwidth is only taken up with requests that need/affect the db. From the example above, with the MySpace media buy, the total for that day was $20-30 I believe in bandwidth costs, and this was a site with a video mixer that had tons of images/video/mp3 and large flash objects. Obviously, mongrel shouldn't be delivering your assets locally anyway, apache/lighty etc should be.
Ultimately it comes down to design and caching when it comes to getting that top performance out of it. My 100 requests/sec wasn't using MemCached or fragment caching, and the mysql db was local. Caching in Rails is a little less than helpful for highly customized for each user sites, but there are plugins that extend it like extended_fragment_cache(ing?), that allow you to templatize things like ID's, etc. Think of say a forum topic listing, where only the topics change as you paginate. With extended fragment caching, you basically draw the page once, and then pass in a hash of the variables that replace the placeholders each time you draw a new page.
Another big thing with ajax sites, is to use link_to_remote with the
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