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Following up from my previous post on the same topic, I’d like to clarify a few points that hopefully address several of the comments on the post.
While the title of the post may be provocative, I am not asserting that Ruby/Rails will be the only framework; I generally don’t believe there needs to be a single framework or in similar absolutes. (For more on this, see my post “Framework Wars: Now all Restaurants are Taco Bell”) The following sentence in the post captures the scope of my position:
I think Ruby/Rails can and will replace Java as the language and platform of choice for software development in the enterprise and will similarly establish itself as the premier option for Web 2.0, cementing the bridge between both markets.
Java has the largest market share, estimated between 20% and 30%, depending on your source. (One example, though there are others, can be found in the following article “Programming Language Trends.” ) Basically, I think Rails will have the largest market share; as Java is currently the default option for software projects (especially in enterprise), I think Ruby/Rails will be the new default. But as with Java, other frameworks will still thrive and will be more appropriate in various cases. I think this shift will take place over the next two to five years.
There are three critical questions that need to be addressed:
The majority of my previous post on this subject addressed Java vulnerability; I think PHP was a disruptive innovation that changed the economics of software development. It is hard to justify a software project as requiring $10 million, more than 20 developers and a few years when a similar application was just created by two developers in six months.
PHP delivered the first blow that has made Java vulnerable, as stakeholders are increasing pressure and questioning of the costs of development. However, Java is general purpose langauge and there is a considerable investment in existing applications and infrastructure. While vulnerable, a successor needs to have similar flexibility.
Rails is not without its problems, as I noted in the previous post:
There is much work to be done on Rails though. There are scalability issues and integration patterns are immature (on average, at least).
Scalability is the most frequently cited criticism of Rails. (I will reference the two related topics of scalability and performance simply as scalability.) It should be noted that for enterprise, which is the primary target audience regarding the claims in this post, most applications do not have more than a few thousand users and scalability is not much of an issue. However, scalability for a popular consumer web application and an internal IT application is very different. I am not trying to simply dismiss the scalability questions, but I think it is only one factor and a broad set of issues affects technology selections.
Twitter is probably the largest Rails application and there has been much discussion of Twitter’s scaling challenges, though the Twitter team continues to improve the situation. Similarly, Facebook is hailed as an example of PHP scaling. While there is no Rails app (to my knowledge), which has scaled to Facebook traffic, Facebook and Twitter are not common scenarios. In these cases, the elected platform will only help or hinder to a degree; the decisions of its developers and how they use their technology options will have the overwhelming impact.
Rails scales horizontally, similarly to PHP, though perhaps not as efficiently in its use of hardware. That said, I think Rails is commonly criticized for scalability problems because it is unfortunately easy to make naive decisions, which still follow Rails conventions, but cause scale problems at low user or page volume. Is this a fundamental failing of Rails? Yes and no. On one hand, you can make decisions with any framework that will cause scalability problems early. However, part of the promise of Rails is that if you follow the conventions, you will be okay.
Scalability is not quite the black, unknown art that it used to be. Most of the patterns and approaches to achieve high scalability are well understood. Java had significant scalability and performance problems in its youth that were addressed. Today, some massively scaled applications are written with Java. Currently, there are Ruby and Rails initiatives that are working on improving performance and scalability, from Rubinius to various ActiveRecord improvements. I expect to see major Rails scalability improvements in the coming year. As an example, the Facebook application Friends for Sale is a Rails app with 300 million views a month.
Assuming Java is vulnerable and technical viability isn’t an obstacle, why Rails and not another framework? I think there are two other commonly cited alternatives: PHP and Pyhon/Django.
As I noted earlier, PHP is responsible, in my opinion, for first exposing Java’s vulnerability to be replaced at the market share leader. However, I think it is hard to use PHP for general purposes beyond web applications and this inhibits its adoption in enterprise. For example, I can’t imagine a socket-based message queue in PHP.
Another challenge for PHP, in my opinion, is that sustainable development is not as easily achieved as it is with Ruby. Automated testing is more flexible in Ruby/Rails and I think the abstraction/plugin architecture of Rails leads to more maintainable applications. (I know of a PHP application, whose developer is quite talented and decided to port from PHP to Rails. The Rails version had only 9% lines of code of the PHP version. While it can be dangerous to draw conclusions based solely on LOC, an application that is 9% the size of the original is easier to maintain and is more flexible.) While such design patterns are possible in PHP, I don’t think they are employed in the average case and I think the average case influences market adoption.
Python and Django are commonly compared to Ruby and Rails. A simple google search of “rails vs. django” yields numerous articles. Ignoring zealot rants on both sides, I think most balanced discussions conclude both platforms can enable productive development teams and the creation of compelling applications. I don’t think technical comparisons inform why Rails has the edge in gaining market share, but market trends themselves.
Consider the following data that I collected by searching on two popular job sites:
I offer these data examples only to convey that I think more developers/stakeholders are taking the Rails plunge than Django. As Pivotal and others have experienced, there are multiples to be gained in productivity gains. I am not claiming Django can’t offer similar productivity gains, but I think it would have to offer even multiples over Rails to get significant numbers of stakeholders or developers to shift from Java to Ruby and then to Django. I haven’t heard anyone claim Django offers productivity multiples over Rails.
Whether you believe the current Rails attention is based on merit or hype, as more and more organizations adopt Ruby/Rails, a synergistic, self-sustaining cycle takes hold and this is the primary consideration in my opinion. As referenced in my last post, Geoffrey Moore, in “Crossing the Chasm”, discusses the adoption curve of technology. He notes that there is a gap in the adoption curve between a relatively small market of early adopters and the huge mass market. Crossing this “chasm” depends on keeping up with market demand and addressing any issues that hinder adoption. This is can be daunting for any organization, but Rails can leverage a strong and motivated community. Rather than a single organization with a few developers trying to bridge any gaps, there are many developers in multiple organizations (and independents) actively working to improve Rails. A few examples (that are also already achieving good results) include Engine Yard, Rubinius, jRuby, and Glassfish.
I close with the short version of my argument:
Ruby on Rails will replace Java as the programming language and platform with dominant market share. Java is vulnerable because alternatives such as PHP have proven viable for application development with dramatically lower costs. While Rails has its shortcomings, concerns such as scalability continue to improve; Rails is not unlike other early-technologies in this regard (consider Java in 1996-98). While other platforms may offer similar productivity benefits to Rails, such as Django, Ruby/Rails is growing in popularity and adoption. This growth can lead to positive, self-sustaining feedback cycle as each phase of Rails adoption improves Rails and encourages more Rails adoption.