So, a few weeks ago I made an offhanded post here about my new-found love for Rails. I'd been skipping off the surface of Ruby for a while, trying to decide if it, or Python, or Groovy, or something else, ought to fill out the empty slot in my tool belt. (I'll save the "why LISP isn't on this list" post for another time.) Rails seemed like an excellent way to put Ruby through a workout, and I had the right sized project to try it out with.
The project itself is not open-source; the client is now and shall remain anonymous. But they are paying me my going rate to do this work, which makes it a commercial Rails project, and it will in the future be installed into some rather large organizations. I can't really say much about what the application's domain is, but I can lay out the general principles of the app.
The application must support multiple users, in the order of 10-100 concurrently. The load isn't particularly high, but the application will be treated like a desktop app (more specifically, a spreadsheet replacement) so it has to be responsive. The application is for managing pieces of a large machine process. There are lots of types of components to be managed, and the relationships between them can be quite complicated. There are no one-to-one relationships in the model, but plenty of one-to-many and many-to-many. In addition to managing the components, the application has to allow for the addition of entirely new categories of components as well as a variety of customizable fields. Finally, the authorization rules call for a breadth of user roles with a complex mapping of permissions to those roles.
I've finally gotten around to running the profiling numbers and doing some comparison between the two systems. I won't spoil the suspense by listing my conclusions up front -- you'll have to scroll through the rest of the post to see them. But, first, let me set the stage: the original application is based on the Java/JSTL/Spring/Hibernate/MySQL stack. I used ACEGI for the security, SpringMVC for the web controller, and was using Hibernate 2.x for the O/RM. To increase performance, I was using the default output caching from SpringMVC and data caching in Hibernate. The re-implementation is in Rails on top of MySQL. The authorization is done through a custom observer and a custom authorization class, which uses a declarative rules file for permission mapping. For performance, I'm using a combination of page caching, action caching, and cache sweepers (observers whose job it is to expire cached pages).
Now, for the comparisons:
Time to Implement I made a comment about this in the previous posts on the topic, and that comment has been quoted widely out in the wide blogosphere as a classic example of Rails hype. So, let me make it plain: any time you re-write an application, it will go almost infinitely faster because you already have a firm grasp on the problem domain. Such was the case for me in my re-write; we'd spent so much time on the domain model and the database schema that the second time through the application, everything already made perfect sense to me. Any comparison of how long it took to implement one or the other is bogus, since the only fair comparison would be to implement two roughly functionally equivalent projects in the two different stacks and measure the competitive results. Since I have not done that, making statements about how it only took 5 days to re-implement the site are almost meaningless. What I can say is that I had more fun implementing it the second time, but that's just personal preference.
Lines of Code This one is a lot more interesting. Folks will tell you all the time that there is a running debate about the meaningfulness of LOC comparisons. They're right; there is a running debate. I just think it's moot. For my money, the fewer lines of code I have to write to get a piece of functionality, *as long as those lines are clear in meaning*, the better off I am. Obfuscated Perl programs don't make the
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Some Numbers at Last
So, a few weeks ago I made an offhanded post here about my new-found love for Rails. I'd been skipping off the surface of Ruby for a while, trying to decide if it, or Python, or Groovy, or something else, ought to fill out the empty slot in my tool belt. (I'll save the "why LISP isn't on this list" post for another time.) Rails seemed like an excellent way to put Ruby through a workout, and I had the right sized project to try it out with.
The project itself is not open-source; the client is now and shall remain anonymous. But they are paying me my going rate to do this work, which makes it a commercial Rails project, and it will in the future be installed into some rather large organizations. I can't really say much about what the application's domain is, but I can lay out the general principles of the app.
The application must support multiple users, in the order of 10-100 concurrently. The load isn't particularly high, but the application will be treated like a desktop app (more specifically, a spreadsheet replacement) so it has to be responsive. The application is for managing pieces of a large machine process. There are lots of types of components to be managed, and the relationships between them can be quite complicated. There are no one-to-one relationships in the model, but plenty of one-to-many and many-to-many. In addition to managing the components, the application has to allow for the addition of entirely new categories of components as well as a variety of customizable fields. Finally, the authorization rules call for a breadth of user roles with a complex mapping of permissions to those roles.
I've finally gotten around to running the profiling numbers and doing some comparison between the two systems. I won't spoil the suspense by listing my conclusions up front -- you'll have to scroll through the rest of the post to see them. But, first, let me set the stage: the original application is based on the Java/JSTL/Spring/Hibernate/MySQL stack. I used ACEGI for the security, SpringMVC for the web controller, and was using Hibernate 2.x for the O/RM. To increase performance, I was using the default output caching from SpringMVC and data caching in Hibernate. The re-implementation is in Rails on top of MySQL. The authorization is done through a custom observer and a custom authorization class, which uses a declarative rules file for permission mapping. For performance, I'm using a combination of page caching, action caching, and cache sweepers (observers whose job it is to expire cached pages).
Now, for the comparisons:
Time to Implement
I made a comment about this in the previous posts on the topic, and that comment has been quoted widely out in the wide blogosphere as a classic example of Rails hype. So, let me make it plain: any time you re-write an application, it will go almost infinitely faster because you already have a firm grasp on the problem domain. Such was the case for me in my re-write; we'd spent so much time on the domain model and the database schema that the second time through the application, everything already made perfect sense to me. Any comparison of how long it took to implement one or the other is bogus, since the only fair comparison would be to implement two roughly functionally equivalent projects in the two different stacks and measure the competitive results. Since I have not done that, making statements about how it only took 5 days to re-implement the site are almost meaningless. What I can say is that I had more fun implementing it the second time, but that's just personal preference.
Lines of Code
This one is a lot more interesting. Folks will tell you all the time that there is a running debate about the meaningfulness of LOC comparisons. They're right; there is a running debate. I just think it's moot. For my money, the fewer lines of code I have to write to get a piece of functionality, *as long as those lines are clear in meaning*, the better off I am. Obfuscated Perl programs don't make the