/var/log/mind

I have 8+ years experience on C++ and Java each and at least consider myself an expert on the latter and used to consider myself one on the former a long time back. For any programmer it is a difficult choice to move away from the platform and the environment in which one has both a substantial investment into and into another one where you essentially throw away years of experience and start as a novice (at least in pure programming terms).

This is not a post which is either to be interpreted as pro Python or anti Java or a pro/anti “name any language you wish”. I will gladly and gleefully go back to C++ / Java when using them makes sense under a context. I am sharing my thoughts and not promoting or denigrating any languages or frameworks here.

Context :

Here’s the shift of context (not all aspects are necessarily relevant to the shift in language). There are many details I have deliberately not got into for obvious protection required for any commercial activity.

• From a relatively large programming team that I used to manage into a small one (yours truly only to begin with)
• From building a commercially owned closed software into open source software development (what is at this stage intended to be though it will take a few months to get there)
• From customers always being large corporates who could often afford substantial hardware into customers who can range from individuals to large corporates
• From mostly internal (intranet) facing to internet facing
• From performance requirements of upto a few hundred thousands of transactions per hour into a completely wide range of requirements based on each customer
• From a very high percentage of writes to a much smaller percentage (ie. read percentages are now much higher)

Initial Choice Set

Given the fact that this application is intended to be hosted on the internet and is primarily a browser based application my choices quickly narrowed down to Java / JEE (something I had a long experience on), PHP (I had developed one web based application with it), Ruby and Python (I only had academic exposure to these). C/C++ did not figure on the choice set for their obvious development overheads in the context of web applications.

I went through a fair degree of thought and creation of dummy applications and the mental to and fro and the the process was not nearly as linear as I will describe below. The process is simplified below simply so that the reader can get at least some insight into my mind and my mind is made to seem a lot less confused than it actually is.

1st Elimination :

Java was the first one to get knocked off. One reason was that Java based applications typically require either a dedicated host or have to work under memory constraints in case of shared hosts. Simply put Java scales exceptionally well but it has a minimum hardware / investment requirement which was not acceptable within this context. The application should be able to worked on shared hosting environments. Another equally important reason was that the productivity of initial development and that of making changes to Java applications is much lesser than the other languages. I was only too acutely aware of the performance implications of this choice, but I believe I the appropriate choice here shall be to scale out especially where the read activity is especially large compared to the writes. Scaling out does require more complex architectures (compared to simply scaling up) but thats the way that is appropriate in this context.

Subsequent thought process

This one was much tougher. Let me delve for a moment into what I believed the key strengths of the various languages were.

Ruby : I really really loved the syntax. Compact, cute ‘n’ thoroughly OO. Strong metaprogramming capabilities
PHP : Massive developer base (especially important when the intention is to eventually open source the application). It is amongst the easiest languages to use. Another advantage in its favour is the ‘C’ness of the syntax which makes it easier for anyone coming in from the C/C++/Java world.
Python : The metaprogramming and OO were almost but not as good as Ruby. I really love the indentation driven syntax. I know many might differ but I really like it and the neat paragraphs and lack of block braces make the code a lot more readable. Current production interpreters seem to be the best performant compared to Ruby and PHP. I know Ruby 1.9 is getting much faster but I suspect it is unlikely to be enough to make it much faster than Python already is.

As I considered the languages, it was important to look at the frameworks. I looked at CodeIgniter, CakePHP and Zend for PHP, Rails for Ruby and Pylons and Django for Python.

I believe one of the important aspects of architecture decision making today is that you bring in the available toolsets / frameworks into the decision making process even when you are attempting to select a language. You are in effect evaluating a package involving both the language and the framework. A specific issue to be noted in my context was that regardless of what framework I chose I was completely sure I would need to change it / extend it due to the fact that some of the basic requirements of the application I am about to build - no well known existing framework supports them. I am certain and convinced this is not a “Not Built Here” syndrome that I am suffering from but simply a necessity of the domain I am attempting to work with.

In terms of ease of use for simpler applications I would rate Rails very highly. Not only does it make the actual programming simple, it gives you a nice set of tools around it to make a lot of typical activities really easy.

2nd elimination

Ruby and Rails went out. The reasons were as follows.

• Ruby is just so well designed from a syntax and OO perspective, that coming from so many years of C++/Java background with a substantial grounding in Object Orientation as implemented by these languages, I really did not get the confidence that I could do it sufficient justice. My fear was that I would keep on finding ways of doing things in a better way in this language (and given my inherent compulsions would feel inclined to refactor code rather than focus on newer development).
• I perceived that Rails was really focused on typical much simpler use cases. What I intend to do requires getting into an immense amount of complexity and I felt fairly certain Rails wasn’t designed for that and that I would spend a very very substantial time reinventing or hacking through Rails.
• One of the strong features of Rails was something I couldn’t really completely come to terms with was “Convention over Configuration”. I still can’t get over some of the implicitness in the environment.

3rd Elimination

Clearly PHP is such a widely used language with so many developers who are already trained on using it, that using it for an as yet intended to be open source application should be a no brainer - Right ? Not in this case. Two reasons why PHP went out.

• I intend to pull off some really complex programming. Given the better OO and metaprogramming capabilities of python - I thought I would be able to keep my code much better concise, structured and readable if I was to use Python (this would’ve been true with Ruby as well!).
• Django - This framework simply came closest to being the framework I would really like to end up with. Thus the gap between what it has vs. what I would like to have was the smallest, and the general design principles were those that I was extremely comfortable with.

In summary : Why these got eliminated

• JEE : The difficulty of using JEE in shared hosting environments and the long development times required made it tough to use it.
• Ruby : I like the language. I was a little intimidated by it. Rails however seemed limited to simpler use cases
• PHP : Wonderful developer base. However didn’t give me the same comfort in terms of its OO capabilities and metaprogramming and did not believe the resultant code would be the most compact, concise, and readable.

In summary : Python and Django : What do I hope to get from them

Now that I have made the choice - what do I expect from these choices at this stage :

• Excellent framework to start off with - provide the maximum initial boost
• Ability to write concise, structured and readable code
• Ability to make changes rapidly
• Reasonably performant application

Other choices that I did not spend too much time on

During this process I also evaluated other languages such as C# and Groovy/Grails. I actually was quite impressed with the recent architecture trends coming from Microsoft and was actually tempted to spend more time on them. However the same reasons that eliminated JEE quickly made these choices unviable as well. I wish I had the luxury to consider other languages as well, but these were what were at the top of my mind, and I did not consider any other languages in the process given the time constraints.

I am missing JEE

I really really will miss JEE. I would love to have used it for the simple fact that I know it so well and this one will require me to move from an expert to a novice category. I will also miss it for the fact that with JEE I knew what it took to deliver exceptionally high performance. Even though I am feeling the JEE separation pangs, I believe Python is the right choice since it will allow for the fastest development, will allow for some really rapid changes (agility in coding), and will allow me to get the developers who shall eventually be joining us come up the curve much faster and be able to deliver more features much faster.

Final thoughts

One thing I realised through the whole process was that there are two strong influencing factors to any architecture choices. The first one obviously is the context. There is no way to compare or contrast any architecture or design choices without putting a context around it. Secondly and this was a little bit more of a surprise to me was that you simply cannot remove personal proclivities from such a choice making process. Since I as an individual am more comfortable with some styles of design than others, and since I am likely to be substantially involved with the initial development, it only seems to make sense that the choice set gets evaluated in this subjective context of individual comfort and therefore the projected individual productivity and effectiveness as well. Note that while in this case I was evaluating it strictly from my own perspective, one could evaluate the choices in the context of Team styles, culture and comfort as well.

A lot of people are wondering whether Java is under threat from a set of nimble languages - PHP / Ruby / Python / Perl. There is a flurry of activity relating to Whether Java is losing the battle for the modern web lot of which are being driven from the earlier post by Andi Gutman Java is losing the battle for the modern Web. Can the JVM save the vendors?.

My recent activities had me visit the same question and the following is how I would summarise the situation and the mechanisms for Java to better compete with these nimble languages.

Current scenario

Yes, I think there is some threat to the scope of use of Java as a server side web application development language. Given the high acceptance of Java in the corporate environments this threat will take some time to play itself out. The sales pitch of Java has often been supported heavily by the vendors, and this has led to lesser focus on making java compete at the non-corporate-enterprise end. The nimble languages compete quite well in this space and combined with the increasing power of hardware which makes them more and more relevant each day for high performance requirements, there is a clear threat of these languages starting from a lower end pushing java out of even the middle end.

Opinion: Dynamism of syntax is not the real issue

What I am not yet fully on board with is the characterisation that the real issue is that Java is lesser dynamic than say PHP / Ruby / Python. Java has a pretty strong set of capabilities and while some may desire more from a syntax perspective I don’t know that thats the real issue. Lack of Closures, Dynamic Types, Duck Typing may make it difficult for java to compete in some contexts only to be at least partially offset in others.

Issue : Shared hosting of java applications

The first real issue is the overhead to develop and then start hosting java applications. It is difficult for host providers to support allowing each user the ability to run their own JVM processes in a sustained fashion. I remember the days when using PostgresSQL required you to have a dedicated server whereas you could use mysql easily by just setting up yourself for a small multi-tenant plan on a web server out there. Today Java is like PostgreSQL of those days. There is no easy way to simply set yourself up to run a small Java application in a shared tenant environment. Even if you did set yourself up chances are that you would be far less than satisfied with the performance in a multi tenant situation even though Java is actually a really really fast language. Java has endeared itself to the corporate environments with their funding for creating large infrastructure stacks and simply hasn’t offered enough opportunities for small enterprises / individuals to create and host their web applications on a shared infrastructure. This takes away an entire community of supporters who when they grew up would’ve carried java along into the larger of their applications.

Issue: Compile cycle

The second issue is the nastily long compile-build cycle. This leads to a scenario where developers need to twiddle their thumbs for half their development times waiting for ant / maven / javac to do their work. It destroys their rhythm and hurts their productivity. The traditional argument of the speed / scale and enterprise-ness of Java over the nimble languages just seems lesser and lesser relevant as these languages start having a nice stack of their own enterprise frameworks and hardware developments whittle away the performance disadvantage. When someone very recently asked me why I was less likely to choose Java for my next project I just said Java is not agile enough. The agility of the nimble languages (no compile-build cycle) coupled with their having adequate performance profiles do lead Java to become lesser capable of competing in the space. By the way one of the real strengths of eclipse is its incremental compilation, but I cannot unfortunately use it with making code changes remotely the way I would be able to change say PHP.

So how can java compete ?

Assuming that java needs to compete with these languages on a better footing, some changes will be required (and some of them quite painful). These will be :

Make java easy to host on multi-tenant application servers

This would definitely require some changes to JVM to reduce the startup / shutdown overheads to make each processes really lightweight. It would also require some attention to how much memory gets utilised. Scenarios such as those I have used in the past to really make applications run faster by caching big time in the RAM are a no-no for multi-tenant hosting. We will thus need a version of JEE which loses the ApplicationContext. We will also need to be able to creatively work with other pools such as connection pools. Finally JEE application servers may need to be restructured to support rapidly dying processes (ie. process per web request). I am no JVM writer so wouldn’t know if some changes might be required to the language but cant think of any major changes that might be required.

Lose the compile cycle

Why can’t “javac” be conditionally executed implicitly at the beginning of “java” process. JSPs generate java on the fly. Similarly python creates the .pyc compiled files on the fly. If the deployment can be done using .java files instead of .class, it would eliminate the compile cycle and allow a developer to change the code in one window, save it, do an alt-tab and go press the reload button on the browser. Compared to all the attention that is being paid to language features like closures and duck typing, I think this is a really really big deal.

How will this help ?

These steps are not targeted towards attracting the developers working in building the corporate enterprise applications (though I am certainly they will break out into three cheers if the compile cycle was done away with - especially in an optional way - ie. the production deployment would still require a war consisting of .class and not .java files). More and more development going forward is going to be characterised by a larger number of smaller applications rather than the old 60s-70s days of small number of large applications. Average applications will get smaller and these will communicate with each other more frequently using web service (REST?) calls. The trend will definitely be towards more in-place remote application reuse by remote invocation rather than through using class libraries. The nimble languages are well positioned to compete in this space. Java isn’t. This will help Java attract and retain developers in a space where currently it is only likely to lose them increasingly. Moreover as application hosting infrastructure starts getting more outsourced and cloud computing gets more prevalent (eg. Amazon Web Services / Google App Engine) Java can at least compete in that space which is otherwise likely to be locked out for it.