I’m gearing up for the next conference stretch. This time it’s San Francisco next week, and I really hope to see lots of people at these conferences - they are gearing up to be something special.

First QCon San Francisco. Except for JAOO, QCon is the best general developer conference I’ve ever been to. Go check out the schedule at http://qconsf.com. This year I’m very excited about doing a full day tutorial about domain specific languages together with Martin Fowler.

I’m also in charge of the languages track, where I have five people who will talk about their experiences with different languages. This time there will not be much introduction to the languages, but instead experience reports, objective descriptions of what worked, what didn’t work and how you can improve your chances of success. The languages covered are Scala, Clojure, Ruby, Groovy and F#. Should be great fun.

Hopefully I will have lots of time to see other presentations too. There are many I would love to see. ThoughtWorks also happens to be a sponsor of QCon, so there will be a booth where it’s a big possibility you can find me or my colleagues.

I will do one day of RubyConf - the Saturday. Funnily enough I haven’t ever been to RubyConf, so I’m looking forward to this too.

Finally, the first ever JRubyConf will happen next Sunday. The program looks really interesting. I’m going to be talking about testing, and also be part of the ending JRuby Core Team panel.

I’m very excited about these conferences. Hope to see you there!

GlassFish v3 provides a REST interface to management and monitoring information as discussed in TOTD #96. As mentioned in that blog "the REST interface is a lower level API that enables toolkit developers and IT administrators to write their custom scripts/clients using language of their choice". This blog introduces a tool that uses the REST API to provide management and monitoring of GlassFish v3 and is written using JavaFX.

This tool is only a proof-of-concept that demonstrates that GlassFish v3 REST interface is functionally very rich and can indeed be used to write third-party administration tools. The tool uses a subset of the REST interface and exposes only a limited amount of management and monitoring capabilities otherwise exposed. After all this is a proof-of-concept :-)

A screencast of this tool in action along with a downloadable JNLP version will soon be available. For now, here is a snapshot of the main window of this tool:

The main screen allows you to enter a URL for the GlassFish administration. Then the GlassFish instance can be stopped/restarted from the main window using the buttons on top right. There is an animation at the bottom of the screen where the glassfish is swimming in the ocean and is directly related to the state of server running in the background. If the server is running, the animation works. If the server is not running then the animation stops as well.

The main screen has three main buttons:

• "List Applications" - list all the applications deployed on the running instance
• "Show Monitoring Levels" - show/Update all the monitoring levels
• "Server Stats" - show statistics of the running server

Clicking on "List Applications" shows the list of applications deployed on this particular instance. Here is how a snapshot looks like for an instance running on my localhost at port 4848:

As shown in the screen, it shows a radio-bulleted list of all the applications. Each bullet is also accompanied by an image indicating the type of application - Web or Rails for now. Select the application and click on "Monitor" button to monitor that particular application. The REST API exposes a vast amount of monitoring data but a subset of monitoring data is displayed for Web and Rails application for now. Here is a snapshot of the monitoring data published for a Web application:

As evident by the list of engines, this web application has EJBs bundled as well. It also shows total number of Servlets/JSPs loaded, number of requests made to this web application and some other monitoring data.

Here is a snapshot of the monitoring data published for a Rails application:

It shows number of JRuby runtimes configured for the application, number of requests sent to the application, number of responses with different HTTP access codes and some other data.

The monitoring levels of different containers can be easily updated by clicking on "Show Monitoring Levels" as shown below:

And finally some server statistics are shown by clicking on "Server Stats" as shown below:

It shows when the server was started, host/port information, version and finally how long the server has been running for. The dials are an animation that shows the server up time.

Here are other related JavaFX and GlassFish related blogs published earlier:

• TOTD #23: JavaFX Client invoking a Metro endpoint
• JavaFX 1.0 launched - access services hosted on embedded GlassFish

How are you going to use the REST interface exposed by GlassFish v3 in your environment ?

Are you using JavaFX with GlassFish together in any way ?

Leave a comment on this blog if you do!

Technorati: javafx glassfish v3 rest web jruby rubyonrails rest administration monitoring management

I just came back from 10 days in Malmö, Sweden, for the Øredev conference. I’ve had a great time. Part of that was because I had Stella with me, and she got to meet all my conference-friends, so that was nice.

But a big part of it is basically just the fact that Øredev is an outstanding conference.

Some of my impressions, things I learned and did in no specific order:

• Hadoop is really cool and I wish I had time to learn more about it. Alex Loddengaard from Cloudera did a very good job introducing this technology in his tutorial. We got to do way fun stuff!
• People liked my talk about Ioke - and I was very happy with how it went too.
• Stuart Halloway is really good at introducing Clojure - I’m looking forward to his talk at QCon SF even more now.
• Me, Tyler Jennings, Neal Ford, Dan North and Stuart Halloway spent several hours of BoF time to create a new BDD framework for Clojure - this was way fun hacking, interesting from a group management and design perspective and just plain fun. There is a distinct possibility that me and Neal will give a talk at the TW US Away Day about this, if anyone is interested.
• Ze Frank is amazing. Really great evening keynote/entertainment.
• Niclas Nilsson and Hans Brattberg did a very accurate depiction of common problems and failure modes of pair programming. Good stuff.
• Tyler Jennings gave an introduction to Software Craftsmanship. Glad I didn’t miss this presentation. Very nicely done.
• Kevlin Henney did a great presentation about agile modeling. I enjoyed it a lot.
• We did a very fun closing panel that was basically just six geeks disagreeing about lots of stuff. I hope everyone else enjoyed it as much as the panel members.

Conclusion: Øredev was a great conference, I was honored to get the chance to speak there and I’ll definitely try to go back next year.

I’m currently sitting in the Beijing ThoughtWorks office, and for some reason language is on my mind… =)

One of the discussions related to DDD that have turned up several times the last few months at conferences
is how you handle ubiquitous language when your domain is not in English. Since most programming languages are based on English, you end up mixing English and Swedish for example, if you are working with a Swedish domain. Of course, the benefits of working with these concepts in Swedish are very hard to argue against. But the dichotomy between the programming language and the domain language is definitely something that hurts my eyes, so I’m generally not very fond of that approach.

In fact, I haven’t heard anyone come up with a good solution to this problem, and this post is not really a solution either.

One of the things I’ve proposed to make this situation better is to create an external DSL that is fully in the domain language. The implementation of that DSL can then be implemented in English. The main benefit is that there is a clear separation.between the domain language and the programming language. On the other hand, the overhead of creating the DSL and also the complexities involved in translating the domain concepts into programming language concepts can become problematic too.

One interesting idea in Cucumber is the idea that you can easily add new natural languages to write the features in. When it comes to user stories at the level of testing that Cucumber provides, it’s really important to use the right language. So it got me thinking, could you use the same kind of approach in a general programming language too?

As an experiment I took a small example program for Ioke, and translated it into Mandarin, with simplified Chinese characters. Of course I used Google Translate for this, so the translation is probably not very good, but the end result is still interesting. I’m not going to try to get this into my blog, so take a look at the file at github instead: http://github.com/olabini/ioke/blob/master/examples/chinese/account.ik. As you can see there is nothing in there that even reeks of English. If you don’t understand Chinese characters it is probably hard to see what’s happening here. Basically an Account object is created, with a “transfer” method and a “print” method. Further down, two instances of this Account object is created, some transfers are made, and then the objects are printed. But provided my translation is not too crappy, this code should make sense to someone reading Chinese.

Now, this is actually extremely simple to implement in Ioke, since it relies on several of the features Ioke handles very easily. That everything is a message really helps, and having everything be first class means I can alias methods and things like that without any worry. Obviously your language also need to handle non-ascii identifiers correctly, but that should be standard in this day and age.

When thinking about it, something similar to do this can be created in languages like Lisp, Smalltalk, Factor, Io and Haskell - but most other languages would struggle. If you have keywords in your language, it’s really a killer - you would need to branch your parser to make it happen.

Of course, this approach only works when you can simply translate from one word to another. If the writing system is right to left, or top to bottom, it’s much more tricky to create a good translation.

I’m also not sure if this is actually a really good idea or not. It might be. The other thing I’ve been thinking about is how to handle multilingual editing. What if you want to be able to switch back and forth between languages? How can you handle identifiers with more than one name. Would you want to?

Lots of unanswered questions here. But it’s still funny to think about. Communication is the main goal, as usual.

This idea came to me as a tweet, but was way too long for a tweet. As it turns out, it’s also something I’ve been saying a lot lately, since it’s the answer to one of the very common arguments against dynamic languages.

The argument usually goes like this: “Dynamically typed languages are fine for smaller programs and simple web applications, but if you’re building something big, something that will be several millions of lines of code, you really need all the tools you can only get from a statically typed language”. Where the statically typed language mentioned is typically Java. The argument is still common enough without any specific language name mentioned though.

Interestingly, there are several problems and fallacies in this seemingly simple argument. I’m not going to tackle all of them here, but just focus on the beginning. Namely the idea that you are building something big. First of all, how do you know that? Have you done anything like it before? And how do you know it would be big in a different language? How do you know you can’t decouple the application in such a way you won’t have to build anything big? There are so many assumptions that can be questioned here. But at the end of the day, my glib answer that summarizes this usually goes something like this:

“Optimizing for your software project becoming big is the same as optimizing a car to hit a rock wall - you are optimizing for failure”

I firmly believe that becoming big is really failure. Once you have a big enough project you have lost. It might still work, but the cost will be extreme, and maintaining it will be a large burden too.

This is the reason I like agile. It emphasizes small, working pieces all the time. If you work with code this way, you can’t really become big. Instead, your project will be forced to be modularized and divided into smaller, more logical components that are highly cohesive and decoupled from each other.

The last two weeks I’ve been working on adding external iterators to Ioke. This work is now done and merged, so I thought I’d just describe it a bit.

But first, why do I need explicit iterators in Ioke? Ruby has gotten by without them for a long time, only implementing a Generator library using continuations, in the standard library. It’s pretty nice, since you don’t really need to do anything explicit to get external iterators from internal ones. Of course, the problem is that it’s very inefficient to implement them like this. So I decided that Ioke should have an explicit protocol for external iterators. You can implement internal iterators using external ones efficiently, but not the other way around.

The two major objects for this in Ioke is called Sequence and Mixins Sequenced. Sequenced is the mixin that gives you access to several helper methods if you implement the “seq” method. If you implement “seq” and mixin Sequenced you will also get an “each” method and Enumerable. The “seq” method is expected to return something that mimics Sequence and has one “next” method, and one “next?” method. That’s all. The “next?” method returns true if there is another element in the sequence, and “next” returns the next one. The protocol is undefined if you call “next” when “next?” would have returned false.

Sequenced give you an “each” method that in addition to the regular each-protocol will also return the result of calling “seq” if you don’t give any arguments to “each”.

Except for that, you will get several methods that just call “seq” and calls the same method on the result of that. These methods are: “mapped”, “collected”, “filtered”, “selected”, “grepped”, “zipped”, “dropped”, “droppedWhile” and “rejected”. These methods are also the same as exist on Sequence. These methods return new sequences that implement the same behavior as the methods with similar names on Enumerable.

Finally, Sequence also mimics Mixin Enumerable. Once you call one of the Enumerable-methods, the whole sequence will be realized, or as much as is necessary to give an answer. A small example of how you could use it:

(1..100000000) mapped(x, x*x) filtered(x, x % 3 == 0) takeWhile( < 10000 )

This example creates a range from 1 to 100,000,000 and finds all the squares that are less than 10,000 an d that is evenly dividable by 3.

Late this Saturday I came home from a hard week in Århus, Denmark. Of course, it’s been a great week but it is definitely a change coming back home after it.

JAOO this year was great, just as you can always expect. What makes JAOO so fantastic is the combination of extraordinary presentations of all kinds, together with the socializing with all the fantastic speakers, and hanging out with the JAOO crew. All in all it’s a lovely time, and I never get enough sleep for some reason.

This year ThoughtWorks was there in force - we had about 12-14 people there, and 8 of us presenting. It’s always fun to be surrounded with TW people.

I’ll not go through the whole schedule, but I do want to share some of my favorites.

Rich Hickey was there, presenting about different aspects relating to Clojure and concurrency. As usual he was excellent, and I heard many good comments about both his presentations.

Intentional Software presented their Language Workbench, which I’ve been playing around with for some time. The presentation generated substantial shock-and-awe from the audience, which was fun to see.

The Tuesday featured the concurrency track, where I spent most my time. The whole track was very good, but it was capped off by Simon Peyton-Jones excellent talk about Nested Data Parallelism in Haskell, a very good presentation that meshed well with my interests. Simon is also a highly entertaining presenter. All in all, that presentation was definitely my favorite one this year.

On Wednesday the two presentations that stands out in my mind was Aino’s about design patterns - interspersed with dating design patterns. Very funny. And the other was by my colleague Richard Durnall, talking about lean.

Very nice stuff, all in all. Martin Fowler, Neal Ford and Rebecca Parsons gave another version of their DSL tutorial the following day. It’s amazing how much this tutorial have evolved since I first saw it.

On the Friday I saw parts of Sam Aaron’s Advanced Ruby tutorial; it’s good. I also gave my tutorial, which went fairly well too.

And that’s JAOO in a nutshell. A great week. It’s weird to come back after such an intense time.

When I heard about a Aloha on Rails, I jumped on the chance to attend a local conference. Having been to several JavaOne conferences, I knew how helpful they were they were for learning best practices, discovering what people were adopting, and getting a view of what's coming down the pike. I definitely got all of that, but I unexpectedly took away a lot more.

For one, it was my first "local" conference (well it is an airplane ride away, but it still felt local to me). I was happy to find that about half the people I talked to are developers in Hawaii and a lot of business cards were exchanged with the hope that we could all meet again at Aloha on Rails 2.

Second, it was a small conference. After the first day and a nice pau nana party put on by Agathon Group (thanks guys), everyone was starting to look familiar and we were having great discussions. The theme of the conference was talk story, and that definitely was going on both in the conference rooms and outside. Small conferences also mean that the speakers are easily accessible. Here were people that I have been following for years, like Chad Fowler, Obie Fernandez, Charles Nutter, and Yehuda Katz, that I got to meet face-to-face, as well as people I hadn't heard about but are now on my follow list, such as Blythe Dunham, Jim Weirich (have you learned to play Hawaiian Lullabye on your uke yet?), and Desi McAdam, founder of DevChix. I don't know if it is because everyone was a Rails developer (and following the Rails way), the aloha atmosphere, or what, but it really was a nice crowd of people to hang with.

Last, while there was a lot of good info about how to do Rails right and what is the best stuff to use, the bigger take away for me was how important it is to develop personal connections and get involved in communities. That seemed to be the theme spreading through all the talks...how good things happen when you connect with and share with people outside of your daily job tasks. So that is my new mantra...Get Connected. The first thing I did when I returned to work was to join an online community of tech people on the Big Island, and I have already exchanged emails with a couple of people (whoo hoo, I am not alone). Next, I need to get involved with an open source community. It might be something in the cloud, or some Rails project (maybe a cloud one), I don't know. If you have suggestions, pass them on.

So, anyway, I am pretty energized by the small conference experience. If you haven't done one, you gotta try it. And a BIG thanks to Seth for making it happen. Great job.

TOTD #110 explained how to create a brand new Rails application using Oracle database and run it using GlassFish v Gem. This Tip Of The Day explains how to create a scaffold for a sample schema that ships with Oracle database. Even though Rails Scaffold are good for, well, scaffolding but they do get you started easily. This blog will use the sample HR schema that comes along with Oracle database.

Lets get started!

1. Copy the reverse_scaffold script in the "script" directory of your application created in TOTD #110. This script generates Model and Forms from a pre-existing database table. More details about this script are here.
2. Edit "config/database.yml" and change the "development" section to:
   
   development:
adapter: oracle_enhanced
host: localhost
database: orcl
username: hr
password: hr
   
   The changes are highlighted in bold, only the username and password values are changed to reflect the default values used with the sample database.
3. Generate the models and forms for "departments" table as:
   

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby script/reverse_scaffold departments department
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
    exists app/models/
    exists app/controllers/
    exists app/helpers/
    create app/views/departments
    exists app/views/layouts/
    exists test/functional/
    exists test/unit/
    create test/unit/helpers/
    exists public/stylesheets/
    create app/views/departments/index.html.erb
    create app/views/departments/show.html.erb
    create app/views/departments/new.html.erb
    create app/views/departments/edit.html.erb
    create app/views/layouts/departments.html.erb
    create public/stylesheets/scaffold.css
    create app/controllers/departments_controller.rb
    create test/functional/departments_controller_test.rb
    create app/helpers/departments_helper.rb
    create test/unit/helpers/departments_helper_test.rb
    route map.resources :departments
    dependency model
    exists app/models/
    exists test/unit/
    exists test/fixtures/
    create app/models/department.rb
    create test/unit/department_test.rb
    create test/fixtures/departments.yml
   

4. Edit "app/models/department.rb" and specify the primary key to "department_id" column by adding:
   

   set_primary_key "department_id"
   

   
   
5. Run the application as:

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby -S glassfish -l
   Starting GlassFish server at: 129.145.133.197:3000 in development environment...
   Writing log messages to: /Users/arungupta/samples/v3/rails/oracle/bookstore/log/development.log.
   Press Ctrl+C to stop.
   Oct 6, 2009 2:14:19 PM com.sun.enterprise.v3.services.impl.GrizzlyProxy start
   INFO: Listening on port 3000
   
   . . .
   

   
   The application is now accessible at "http://localhost:3000/departments" and looks like:
   
6. Similarly, create the model and forms for "employees" table as:
   
   

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby script/reverse_scaffold employees employee
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
    exists app/models/
    exists app/controllers/
    exists app/helpers/
    create app/views/employees
    exists app/views/layouts/
    exists test/functional/
    exists test/unit/
    exists test/unit/helpers/
    exists public/stylesheets/
    create app/views/employees/index.html.erb
    create app/views/employees/show.html.erb
    create app/views/employees/new.html.erb
    create app/views/employees/edit.html.erb
    create app/views/layouts/employees.html.erb
    identical public/stylesheets/scaffold.css
    create app/controllers/employees_controller.rb
    create test/functional/employees_controller_test.rb
    create app/helpers/employees_helper.rb
    create test/unit/helpers/employees_helper_test.rb
    route map.resources :employees
    dependency model
    exists app/models/
    exists test/unit/
    exists test/fixtures/
    create app/models/employee.rb
    create test/unit/employee_test.rb
    create test/fixtures/employees.yml
   

   
   Specify the primary key to "employee_id" by adding the following to "app/models/employee.rb" as:
   

   set_primary_key "employee_id"
   

   
   The scaffolded table is now available at "http://localhost:3000/employees" and looks like:
   
   

So we created a simple Rails CRUD application accessing information from a pre-existing table in the Oracle database server.

Thanks to @mediachk for all the help!

A complete archive of all the TOTDs is available here. The complete list of Rails blog entries are available here.

This and other similar applications will be demonstrated at the upcoming Oracle Open World.

Technorati: totd oracle database glassfish v3 jruby rails oow

GlassFish v3 is the Reference Implementation for Java EE 6. Following the "extensibility" principle of Java EE 6, it also allows Ruby-on-Rails, Groovy and Grails and Python/Django applications to be seamlessly deployed as well, without any additional packaging. This blog has published multiple entries on deploying a Rails application on GlassFish as given below:

• TOTD #105: Monitor Rails application using JavaScript
• TOTD #104: Redmine, Typo, Substruct on GlassFish v3
• TOTD #84: Apache + mod_proxy_balancer to load balance Rails applications on GlassFish
• TOTD #81: nginx to load balance Rails applications on GlassFish Gem
• TOTD #73: Deploying Rails application as WAR on GlassFish v2.1
• TOTD #72: Deploying Rails application on GlassFish v3
• TOTD #70: Deploying Rails application on GlassFish Gem

All the existing applications have used JavaDB, SQLite3, or MySQL as the database so far. In the process of getting ready for the upcoming Oracle Open World 2009, this Tip Of The Day will show how to use an Oracle database with a JRuby-on-Rails application deployed on GlassFish v3.

Lets get started!

1. Install Oracle database as explained in TOTD #106.
2. Configure JRuby/Rails in GlassFish v3 using one of the mechanisms explained in TOTD #104. Alternatively you can also install the GlassFish gem as:
   

   >./bin/jruby -S gem install glassfish
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
   Successfully installed rack-1.0.0
   Successfully installed glassfish-0.9.5-universal-java
   2 gems installed
   Installing ri documentation for rack-1.0.0...
   Installing ri documentation for glassfish-0.9.5-universal-java...
   Installing RDoc documentation for rack-1.0.0...
   Installing RDoc documentation for glassfish-0.9.5-universal-java...
   

   
   This blog will use GlassFish Gem for running the application described below.
3. Create a new database user and grant rights using SQL*Plus as shown:
   

   Macintosh-187:~ oracle$ sqlplus "/ as sysdba"
   SQL*Plus: Release 10.2.0.4.0 - Production on Thu Oct 1 12:32:33 2009
   
   Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.
   
   
   Connected to:
   Oracle Database 10g Release 10.2.0.4.0 - Production
   
   SQL> CREATE USER glassfish IDENTIFIED BY glassfish DEFAULT tablespace users TEMPORARY tablespace temp;
   
   User created.
   
   SQL> GRANT CONNECT TO glassfish IDENTIFIED BY glassfish;
   
   Grant succeeded.
   
   SQL> GRANT UNLIMITED TABLESPACE TO glassfish;
   
   Grant succeeded.
   
   SQL> GRANT CREATE TABLE TO glassfish;
   
   Grant succeeded.
   
   SQL> GRANT CREATE SEQUENCE TO glassfish;
   
   Grant succeeded.
   SQL> exit
   Disconnected from Oracle Database 10g Release 10.2.0.4.0 - Production
   
   

   The user name and password are chosen as "glassfish" for simplicity. This is not a recommended setting for production usage though.
4. Copy Oracle JDBC drivers (odjc6.jar) in JRUBY_HOME/lib directory.
5. Create a simple Rails application
   1. Make sure the following gems are pre-installed:
      

      rails (2.3.4)
      activerecord-jdbc-adapter (0.9.2)
      glassfish (0.9.5)
      

      
      If not, then install them as:

      jruby -S gem install rails activercord-jdbc-adapter glassfish
      

   2. Create a simple Rails application as:
      

      jruby -S rails bookstore -d oracle
      

      
      
   3. Using the normal "jdbc" adapter will give the following error later:
      
      

      ActionView::TemplateError (book_url failed to generate from {:controller=>"books", :action=>"show", :id=>#<Book id: #<BigDecimal:3feef1eb,'10000.0',1(8)>, title: "Ultramarathon Man", author: "Dean Karnazes", created_at: "2009-10-06 00:03:14", updated_at: "2009-10-06 00:03:14">}, expected: {:controller=>"books", :action=>"show"}, diff: {:id=>#<Book id: #<BigDecimal:459bdb65,'10000.0',1(8)>, title: "Ultramarathon Man", author: "Dean Karnazes", created_at: "2009-10-06 00:03:14", updated_at: "2009-10-06 00:03:14">}) on line #13 of app/views/books/index.html.erb:
      

      
      
      As evident, the "id" column is returned as BigDecimal where as it should be integer. Fortunately the fix is simple, install the "oracle_enhanced_adapter" (docs) as:
      
      

      bookstore >~/tools/jruby/bin/jruby -S gem install activerecord-oracle_enhanced-adapter
      JRuby limited openssl loaded. gem install jruby-openssl for full support.
      http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
      Successfully installed activerecord-oracle_enhanced-adapter-1.2.2
      1 gem installed
      Installing ri documentation for activerecord-oracle_enhanced-adapter-1.2.2...
      Installing RDoc documentation for activerecord-oracle_enhanced-adapter-1.2.2...
      

      
      Using this "enhanced adapter" is highly recommended for connecting with Oracle databases from Rails applications.
   4. Edit "config/database.yml" and change the "development" section to:
      

      development:
       adapter: oracle_enhanced
       host: localhost
       database: orcl
       username: glassfish
       password: glassfish
      

      
      Notice, the username and password values are the same as chosen in the SQL statements above.
   5. Generate a scaffold as:
      
      

      bookstore >~/tools/jruby/bin/jruby script/generate scaffold book title:string author:string
      JRuby limited openssl loaded. gem install jruby-openssl for full support.
      http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
       exists app/models/
       exists app/controllers/
       exists app/helpers/
       create app/views/books
       exists app/views/layouts/
       exists test/functional/
       exists test/unit/
       create test/unit/helpers/
       exists public/stylesheets/
       create app/views/books/index.html.erb
       create app/views/books/show.html.erb
       create app/views/books/new.html.erb
       create app/views/books/edit.html.erb
       create app/views/layouts/books.html.erb
       create public/stylesheets/scaffold.css
       create app/controllers/books_controller.rb
       create test/functional/books_controller_test.rb
       create app/helpers/books_helper.rb
       create test/unit/helpers/books_helper_test.rb
       route map.resources :books
       dependency model
       exists app/models/
       exists test/unit/
       exists test/fixtures/
       create app/models/book.rb
       create test/unit/book_test.rb
       create test/fixtures/books.yml
       create db/migrate
       create db/migrate/20091005233152_create_books.rb
      
      

   6. Prepare your application for JDBC as:
      

      bookstore >~/tools/jruby/bin/jruby script/generate jdbc
      JRuby limited openssl loaded. gem install jruby-openssl for full support.
      http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
       exists config/initializers
       create config/initializers/jdbc.rb
       exists lib/tasks
       create lib/tasks/jdbc.rake
      

      
      
   7. Migrate the database as:
      

      ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby -S rake db:migrate
      (in /Users/arungupta/samples/v3/rails/oracle/bookstore)
      == CreateBooks: migrating ====================================================
      -- create_table(:books)
       -> 0.0740s
       -> 0 rows
      == CreateBooks: migrated (0.0750s) ===========================================
      

      
      
6. Lets run the application as:
   

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby -S glassfish -l
   Starting GlassFish server at: 129.145.133.197:3000 in development environment...
   Writing log messages to: /Users/arungupta/samples/v3/rails/oracle/bookstore/log/development.log.
   Press Ctrl+C to stop.
   Oct 6, 2009 9:45:51 AM com.sun.enterprise.v3.services.impl.GrizzlyProxy start
   INFO: Listening on port 3000
   
   . . .
   

   
   
   he application is now accessible at "http://localhost:3000/books" and looks like:
   
   
   
   Click on "New Book" and enter the values as shown:
   
   
   
   Click on "Create" to see the output as:
   
   
   
   Click on "Back" to see the main page as:
   
   
   
   After adding another book, this page looks like:
   
   
   
   And another book ...
   
   
   
   

So we created a brand new JRuby/Rails application and ran it using GlassFish and Oracle backend. A subsequent blog entry will show how to create a similar application using an existing database.

A complete archive of all the TOTDs is available here. The complete list of Rails blog entries are available here.

This and other similar applications will be demonstrated at the upcoming Oracle Open World.

Technorati: totd oracle database glassfish v3 jruby rails oow

I spent this Friday and Saturday in London at the RubyFoo conference, organized by Trifork. RubyFoo is a small pre-conference to the larger JAOO conference. As you might expect, it’s focused on Ruby, and it’s quite small. On the friday we were about 50 people, and on Saturday about 40. The small amount of people and the fact that all presentations were in the same track made it much easier to network and communicate with people. I liked the focus this gave to the conference, and it was also an excellent opportunity to meet new people and get new ideas.

On the Friday there were five presentations, and on the Saturday it was an open spaces. The five presentations were all focused around the area of communicative programming. I talked about JRuby and did several demonstrations of how JRuby can be used to call out to different languages. My examples included talking to Clojure, Erlang and Haskell.

After me, Aslak Hellesøy talked about Cucumber and how Cucumber supports lots of different programming languages. Very cool. Aslak always give good presentations.

We then had lunch, and then Sam Aaron gave an interesting talk about communicative programming, and the essence of what we are doing. Very cerebral, definitely something that sparked lots of thoughts in peoples minds.

Adam Wiggins gave a talk about Heruko. I haven’t actually tried Heruko yet, but it looks very cool.

Finally, Matz gave a talk about the different styles of programming in Ruby, tied in with his history of creating Ruby and what the inspirations were. Very nice.

On the Saturday my colleague Dan North facilitated the open spaces discussions. I gave a 30 minute talk about Ioke - people seemed to enjoy it. After that Dan North, me, Aslak and a few others had a discussion about static versus dynamic typing.

After lunch I held a discussion about Ruby 1.9, getting some ideas why people weren’t using it, and what problems the people using it had encountered.

Finally, me, Aslak and Sam sat down to add Ioke support to Cucumber. This went really well - and I liked pairing with Aslak. Sadly I couldn’t stay until we were done, but Aslak and the others continued while I was heading out to the airport.

All in all, RubyFoo was a great conference, and I hope they can keep the same size the next time. 50 people were really a great size, and I liked the discussions we had.

Monitoring infrastructure in GlassFish v3 is getting an extreme makeover. Prashanth defines it very nicely in his detailed introduction:

We provide a way to dynamically and non-intrusively generate monitoring events from any of the GlassFish runtime classes, the ability to listen to these events, collect the statistics and expose these statistics through various standard clients.

The "dynamic" nature indicates that monitoring can be turned ON or OFF in a GlassFish instance running in production environment. It also means the granularity to which the monitoring information can be generated. This information can be generated for not only a traditional Java EE applications, but Rails, Django and other type of applications that can be easily deployed on GlassFish v3. And that is extensible for other pluggable containers too. The data can be accessed using multiple mechanisms providing the administrator a wide variety of choice for tools, e.g. DTrace, JMX, REST, asadmin CLI, and Admin Console and thus another point in favor of "dynamic".

The "non-intrusive" behavior means that monitoring can be used in production environment with minimal overhead. It also means that there is no overhead when monitoring is not enabled. Anyway, monitoring needs to be explicitly enabled as explained below.

As mentioned above, there are multiple ways to access the monitoring data. The different ways to access the monitoring data are:

1. DTrace scripts (only on Solaris)
2. asadmin CLI
3. Admin Console
4. JMX/jConsole
5. REST
6. Custom client using a 3rd party scripting language (available as value-add feature to paid customers only)

This Tip Of The Day will describe how to access the monitoring data using asadmin CLI and a JavaScript client. Note that the JavaScript client feature is available as a value-add to the community version of GlassFish and available only to the paid customers.

This tip will use a pre-deployed Rails application as (Redmine as described in TOTD #104) on a nightly GlassFish v3 build (CI, nightly, or promoted) and explains how to monitor this application.

Using the terminology defined in Monitoring in GlassFish v3 blog, the JRuby subsystem in GlassFish has multiple probe providers and each provider has multiple probes. The JRuby subsystem also provides multiple stats providers with probe listeners. All of these elements are linked using the monitoring infrastructure in GlassFish.

Lets monitor our Rails application

Monitoring using asadmin CLI

By default the monitoring is turned OFF for all the components. Lets enable monitoring for the JRuby container as:

asadmin enable-monitoring --level jruby-container=HIGH

The other possible values are "LOW" and "OFF". All the probes publishing monitoring data can be listed as:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin list --monitor=true "*"
server
server.containers
server.containers.jruby
server.containers.jruby.applications
server.containers.jruby.http
server.containers.jruby.http.redmine-0.8.5
server.containers.jruby.runtime-pool
server.containers.jruby.runtime-pool.redmine-0.8.5

Command list executed successfully.

A snapshot of the monitoring data can be obtained as:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin get --monitor=true "*jruby*"
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-appName = redmine-0.8.5
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-description =
 server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-environment = development
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-jrubyVersion = 1.3.0
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-lastsampletime = 1253322280437
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-name = redmine-0.8.5
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-rubyFramework = rails
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-starttime = 1253322280437
server.containers.jruby.applications.activerubyapplications.redmine-0.8.5-unit =
server.containers.jruby.applications.activerubyappscount-count = 1
server.containers.jruby.applications.activerubyappscount-description = Number of currently loaded Ruby applications
server.containers.jruby.applications.activerubyappscount-lastsampletime = 1253322279921
server.containers.jruby.applications.activerubyappscount-name = ActiveRubyApplications
server.containers.jruby.applications.activerubyappscount-starttime = 1253322279922
server.containers.jruby.applications.activerubyappscount-unit = count
server.containers.jruby.http.redmine-0.8.5.address = null
server.containers.jruby.http.redmine-0.8.5.averageprocessingtime = 0
server.containers.jruby.http.redmine-0.8.5.count200-count = 0
server.containers.jruby.http.redmine-0.8.5.count200-description = Number of responses with a status code equal to 200
server.containers.jruby.http.redmine-0.8.5.count200-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count200-name = Count200
server.containers.jruby.http.redmine-0.8.5.count200-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count200-unit = count
server.containers.jruby.http.redmine-0.8.5.count2xx-count = 0
server.containers.jruby.http.redmine-0.8.5.count2xx-description = Number of responses with a status code in the 2xx range
server.containers.jruby.http.redmine-0.8.5.count2xx-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count2xx-name = Count2xx
server.containers.jruby.http.redmine-0.8.5.count2xx-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count2xx-unit = count
server.containers.jruby.http.redmine-0.8.5.count302-count = 0
server.containers.jruby.http.redmine-0.8.5.count302-description = Number of responses with a status code equal to 302
server.containers.jruby.http.redmine-0.8.5.count302-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count302-name = Count302
server.containers.jruby.http.redmine-0.8.5.count302-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count302-unit = count
server.containers.jruby.http.redmine-0.8.5.count304-count = 0
server.containers.jruby.http.redmine-0.8.5.count304-description = Number of responses with a status code equal to 304
server.containers.jruby.http.redmine-0.8.5.count304-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count304-name = Count304
server.containers.jruby.http.redmine-0.8.5.count304-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count304-unit = count
server.containers.jruby.http.redmine-0.8.5.count3xx-count = 0
server.containers.jruby.http.redmine-0.8.5.count3xx-description = Number of responses with a status code in the 3xx range
server.containers.jruby.http.redmine-0.8.5.count3xx-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count3xx-name = Count3xx
server.containers.jruby.http.redmine-0.8.5.count3xx-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count3xx-unit = count
server.containers.jruby.http.redmine-0.8.5.count400-count = 0
server.containers.jruby.http.redmine-0.8.5.count400-description = Number of responses with a status code equal to 400
server.containers.jruby.http.redmine-0.8.5.count400-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count400-name = Count400
server.containers.jruby.http.redmine-0.8.5.count400-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count400-unit = count
server.containers.jruby.http.redmine-0.8.5.count401-count = 0
server.containers.jruby.http.redmine-0.8.5.count401-description = Number of responses with a status code equal to 401
server.containers.jruby.http.redmine-0.8.5.count401-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count401-name = Count401
server.containers.jruby.http.redmine-0.8.5.count401-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count401-unit = count
server.containers.jruby.http.redmine-0.8.5.count403-count = 0
server.containers.jruby.http.redmine-0.8.5.count403-description = Number of responses with a status code equal to 403
server.containers.jruby.http.redmine-0.8.5.count403-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count403-name = Count403
server.containers.jruby.http.redmine-0.8.5.count403-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count403-unit = count
server.containers.jruby.http.redmine-0.8.5.count404-count = 0
server.containers.jruby.http.redmine-0.8.5.count404-description = Number of responses with a status code equal to 404
server.containers.jruby.http.redmine-0.8.5.count404-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count404-name = Count404
server.containers.jruby.http.redmine-0.8.5.count404-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count404-unit = count
server.containers.jruby.http.redmine-0.8.5.count4xx-count = 0
server.containers.jruby.http.redmine-0.8.5.count4xx-description = Number of responses with a status code in the 4xx range
server.containers.jruby.http.redmine-0.8.5.count4xx-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count4xx-name = Count4xx
server.containers.jruby.http.redmine-0.8.5.count4xx-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count4xx-unit = count
server.containers.jruby.http.redmine-0.8.5.count503-count = 0
server.containers.jruby.http.redmine-0.8.5.count503-description = Number of responses with a status code equal to 503
server.containers.jruby.http.redmine-0.8.5.count503-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count503-name = Count503
server.containers.jruby.http.redmine-0.8.5.count503-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count503-unit = count
server.containers.jruby.http.redmine-0.8.5.count5xx-count = 0
server.containers.jruby.http.redmine-0.8.5.count5xx-description = Number of responses with a status code in the 5xx range
server.containers.jruby.http.redmine-0.8.5.count5xx-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count5xx-name = Count5xx
server.containers.jruby.http.redmine-0.8.5.count5xx-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.count5xx-unit = count
server.containers.jruby.http.redmine-0.8.5.countother-count = 0
server.containers.jruby.http.redmine-0.8.5.countother-description = Number of responses with other status codes
server.containers.jruby.http.redmine-0.8.5.countother-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.countother-name = CountOther
server.containers.jruby.http.redmine-0.8.5.countother-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.countother-unit = count
server.containers.jruby.http.redmine-0.8.5.errorcount-count = 0
server.containers.jruby.http.redmine-0.8.5.errorcount-description = Number of responses with a status code greater than 400
server.containers.jruby.http.redmine-0.8.5.errorcount-lastsampletime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.errorcount-name = ErrorCount
server.containers.jruby.http.redmine-0.8.5.errorcount-starttime = 1253322280245
server.containers.jruby.http.redmine-0.8.5.errorcount-unit = count
server.containers.jruby.http.redmine-0.8.5.requestcount-count = 0
server.containers.jruby.http.redmine-0.8.5.requestcount-description = Number of HTTP requests received
server.containers.jruby.http.redmine-0.8.5.requestcount-lastsampletime = 1253322280243
server.containers.jruby.http.redmine-0.8.5.requestcount-name = RequestCounter
server.containers.jruby.http.redmine-0.8.5.requestcount-starttime = 1253322280243
server.containers.jruby.http.redmine-0.8.5.requestcount-unit = count
server.containers.jruby.http.redmine-0.8.5.requestpersecond = null
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-count = 1
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-description = Currently active runtimes
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-lastsampletime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-name = activeRuntimes
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-starttime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.activeruntimes-unit = count
server.containers.jruby.runtime-pool.redmine-0.8.5.applicationname = redmine-0.8.5
server.containers.jruby.runtime-pool.redmine-0.8.5.contextpath = /redmine-0.8.5
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-count = 1
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-description = Maximum active runtimes
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-lastsampletime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-name = hardMaximum
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-starttime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmaximum-unit = count
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-count = 1
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-description = Minimum active runtimes
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-lastsampletime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-name = hardMinimum
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-starttime = 1253322280241
server.containers.jruby.runtime-pool.redmine-0.8.5.hardmminimum-unit = count

Command get executed successfully.

The command asadmin get --monitor=true "*jruby*" dumps a snapshot of the monitoring data such as the number of Ruby currently applications loaded, application name, JRuby version, environment (development / test / production), currently active runtimes, min/max runtimes, number of HTTP requests / responses with a certain HTTP code and much more information. It basically dumps all the JRuby monitoring information captured so far.

An alternate regular expression may be specified such as:

asadmin get --monitor=true "*jruby*runtime-pool*"

Monitoring using JavaScript client

Third-party scripting client are a value-add to the community versions. Just like Enterprise Manager, the value-add will be available as a patch to the users who purchase commercial support. Lets see what can be done with it though.

First of all you can type the command "list-probes" to see a list of all the probes that are available. A typical output will look like:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin list-probes
glassfish:kernel:connections-keep-alive:decrementCountConnectionsEvent decrementCountConnectionsEvent(java.lang.String)
glassfish:web:web-module:webModuleStoppedEvent webModuleStoppedEvent(java.lang.String, java.lang.String)
glassfish:jca:connection-pool:connectionValidationFailedEvent connectionValidationFailedEvent(java.lang.String, int)
glassfish:jca:work-management:workWaitedFor workWaitedFor(java.lang.String, long)
glassfish:jdbc:connection-pool:connectionTimedOutEvent connectionTimedOutEvent(java.lang.String)
glassfish:security:ejbpolicy:ejbPCCreationEvent ejbPCCreationEvent(java.lang.String)
glassfish:kernel:thread-pool:threadReturnedToPoolEvent threadReturnedToPoolEvent(java.lang.String, java.lang.String)
glassfish:web:session:sessionPersistedEndEvent sessionPersistedEndEvent(java.lang.String, java.lang.String, java.lang.String)
glassfish:web:http-service:requestStartEvent requestStartEvent(java.lang.String, java.lang.String, java.lang.String, int, java.lang.String, java.lang.String)
glassfish:jdbc:connection-pool:connectionsFreedEvent connectionsFreedEvent(java.lang.String, int)
glassfish:jdbc:connection-pool:toString toString(java.lang.String, java.lang.StringBuffer)
glassfish:jca:connection-pool:decrementFreeConnectionsSizeEvent decrementFreeConnectionsSizeEvent(java.lang.String, int)
glassfish:kernel:connections-keep-alive:incrementCountFlushesEvent incrementCountFlushesEvent(java.lang.String)
glassfish:webservices:109:deploy deploy(com.sun.enterprise.deployment.Application, com.sun.enterprise.deployment.WebServiceEndpoint)
glassfish:jca:connection-pool:connectionAcquiredEvent connectionAcquiredEvent(java.lang.String)
glassfish:web:http-service:requestEndEvent requestEndEvent(java.lang.String, java.lang.String, java.lang.String, int, java.lang.String, java.lang.String, int)
glassfish:kernel:connections-keep-alive:incrementCountRefusalsEvent incrementCountRefusalsEvent(java.lang.String)
glassfish:kernel:connections:connectionConnectedEvent connectionConnectedEvent(java.lang.String, int)
glassfish:kernel:file-cache:addHeapSizeEvent addHeapSizeEvent(java.lang.String, long)
glassfish:jruby:runtime-pool:runtimePoolUpdateEvent runtimePoolUpdateEvent(java.lang.String, int, int, int, int, int)
glassfish:security:web:securityManagerCreationEvent securityManagerCreationEvent(java.lang.String)
glassfish:security:web:securityManagerDestructionEvent securityManagerDestructionEvent(java.lang.String)
glassfish:webservices:ri:undeploy undeploy(com.sun.xml.ws.transport.http.servlet.ServletAdapter)
glassfish:web:session:sessionPersistedStartEvent sessionPersistedStartEvent(java.lang.String, java.lang.String, java.lang.String)
glassfish:ejb:pool:objectAddedEvent ejbObjectAddedEvent()
glassfish:ejb:bean:methodStartEvent ejbMethodStartEvent(java.lang.String, java.lang.String, java.lang.String, java.lang.reflect.Method)
glassfish:jdbc:connection-pool:connectionRequestServedEvent connectionRequestServedEvent(java.lang.String, long)

All the JRuby probes can be easily listed as:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin list-probes | grep jruby
glassfish:jruby:runtime-pool:runtimePoolUpdateEvent runtimePoolUpdateEvent(java.lang.String, int, int, int, int, int)
glassfish:jruby:http:requestStartEvent requestStartEvent(java.lang.String, java.lang.String, int)
glassfish:jruby:jruby-container:jrubyModuleStartedEvent jrubyModuleStartedEvent(java.lang.String, java.lang.String, java.lang.String, java.lang.String)
glassfish:jruby:jruby-container:jrubyModuleStoppedEvent jrubyModuleStoppedEvent(java.lang.String, java.lang.String, java.lang.String)
glassfish:jruby:http:requestEndEvent requestEndEvent(java.lang.String, int)
glassfish:jruby:runtime-pool:runtimePoolStartEvent runtimePoolStartEvent(java.lang.String, int, int, int, int, int, int, int)

More detailed information about each probe can be easily found by giving the command:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin list-probes --manpage=true glassfish:jruby:runtime-pool:runtimePoolUpdateEvent

This will show the detailed information ("man" pages) about the specific probe. A JavaScript client to monitor the deployed Rails application and gather the relevant statistics can be written using these pages as shown below:

moduleStarted = function(appName, appType, env, jruby) {
    client.print( '\n log> Deployed a \'' + appType + '\' app named \'' + appName + '\' in \'' + env + '\' environment with JRuby \'' + jruby + '\'.');
}

moduleStopped = function(appName, appType, env) {
    client.print( '\n log> Undeployed a \'' + appType + '\' app named \'' + appName + '\' in \'' + env + '\' environment.');
}

requestStarted = function(contextPath, serverName, port) {
    client.print( '\n log> Request started at \'' + contextPath + '\' hosted on \'' + serverName + ':' + port + '\'');
}

requestEnded = function(contextPath, statusCode) {
    client.print( '\n log> Request stopped at \'' + contextPath + '\' with status code \'' + statusCode + '\'');
}

runtimePoolStart = function(appName, activeRuntimes, queueSize) {
   client.print( '\n log> JRuby runtime pool started for the app \'' + appName + '\': active runtime - ' + activeRuntimes + ', queue size - ' + queueSize);
}

runtimePoolUpdate = function(appName, activeRuntimes, queueSize) {
   client.print( '\n log> JRuby runtime pool updated for the app \'' + appName + '\': active runtime - ' + activeRuntimes + ', queue size - ' + queueSize);
}

moduleStartedParams = java.lang.reflect.Array.newInstance(java.lang.String, 4);
moduleStartedParams[0]="appName";
moduleStartedParams[1]="applicationType";
moduleStartedParams[2]="environment";
moduleStartedParams[3]="jrubyVersion";
scriptContainer.registerListener('glassfish:jruby:jruby-container:jrubyModuleStartedEvent', moduleStartedParams, 'moduleStarted');

moduleStoppedParams = java.lang.reflect.Array.newInstance(java.lang.String, 3);
moduleStoppedParams[0]="appName";
moduleStoppedParams[1]="applicationType";
moduleStoppedParams[2]="environment";
scriptContainer.registerListener('glassfish:jruby:jruby-container:jrubyModuleStoppedEvent', moduleStoppedParams, 'moduleStopped');

requestStartParams = java.lang.reflect.Array.newInstance(java.lang.String, 3);
requestStartParams[0]="contextPath";
requestStartParams[1]="serverName";
requestStartParams[2]="port";
scriptContainer.registerListener('glassfish:jruby:http:requestStartEvent', requestStartParams, 'requestStarted');

requestEndParams = java.lang.reflect.Array.newInstance(java.lang.String, 2);
requestEndParams[0]="contextPath";
requestEndParams[1]="statusCode";
scriptContainer.registerListener('glassfish:jruby:http:requestEndEvent', requestEndParams, 'requestEnded');

runtimePoolParams = java.lang.reflect.Array.newInstance(java.lang.String, 3);
runtimePoolParams[0]="appName";
runtimePoolParams[1]="activeRuntimes";
runtimePoolParams[2]="queueSize";
scriptContainer.registerListener('glassfish:jruby:runtime-pool:runtimePoolStartEvent', runtimePoolParams, 'runtimePoolStart');
scriptContainer.registerListener('glassfish:jruby:runtime-pool:runtimePoolUpdateEvent', runtimePoolParams, 'runtimePoolUpdate');

This script register listeners for different probe events, pass a set of parameters that need to be captured, and print the information in a callback method specified during registration. The number of listeners and parameters / listener may be altered to meet your data capturing needs.

This script is stored in a file "monitor-rails.js" and used as described below. As a Rails application is deployed, requests invoked, and undeployed, the following messages are printed on the console:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin run-script monitor-rails.js


 log> Deployed a 'rails' app named 'redmine-0.8.5' in 'development' environment with JRuby '1.3.0'.
 log> JRuby runtime pool started for the app 'redmine-0.8.5': active runtime - 1, queue size - 0
 log> Request started at '/redmine-0.8.5' hosted on 'localhost:8080'
 log> Request stopped at '/redmine-0.8.5' with status code '200'
 log> Request started at '/redmine-0.8.5' hosted on 'localhost:8080'
 log> Request stopped at '/redmine-0.8.5' with status code '200'
 log> Undeployed a 'rails' app named 'redmine-0.8.5' in 'development' environment.

Note "run-script" is the command that comes as part of the value-add. As described earlier, a snapshot of the monitoring information can be easily captured using asadmin as:

~/tools/glassfish/v3/9-18/glassfishv3 >./bin/asadmin get --monitor=true "*jruby*request*"
server.containers.jruby.http.redmine-0.8.5.requestcount-count = 2
server.containers.jruby.http.redmine-0.8.5.requestcount-description = Number of HTTP requests received
server.containers.jruby.http.redmine-0.8.5.requestcount-lastsampletime = 1253638362651
server.containers.jruby.http.redmine-0.8.5.requestcount-name = RequestCounter
server.containers.jruby.http.redmine-0.8.5.requestcount-starttime = 1253638362651
server.containers.jruby.http.redmine-0.8.5.requestcount-unit = count
server.containers.jruby.http.redmine-0.8.5.requestpersecond = 1

Command get executed successfully.

As you can see, the total number of requests is shown as "2".

Just for fun, I ran Apache ab with 20 requests and 4 concurrency ("-n 20 -c 4") on "http://localhost:8080/redmine-0.8.5" and saw the following results:

The server was restarted between each run. These numbers were generated on my development machine so they are most likely skewed. But as a development benchmark the numbers do indicate that GlassFish v3 monitoring is truly non-intrusive. The total time taken for requests, requests/second, and time/request is pretty much identical.

Future blogs will cover how to access this data using web-based DTrace scripts, web-based Admin Console, jConsole, and REST interface.

A complete archive of all the tips is available here.

Technorati: totd glassfish v3 monitoring asadmin javascript jruby rails redmine

Last week I finally bit the bullet and rewrote the Ioke parser. I’m pretty happy about the end result actually, but it does involve moving away from Antlr’s as a parser generator. In fact, the new parser is handwritten - and as such goes against my general opinion to generate everything possible. I would like to quickly take a look at the reasons for doing this and also what the new parser will give Ioke.

For reference, the way the parser used to work was that the Antlr generated lexer and parser gave the Ioke runtime an Antlr Tree structure. This tree structure was then walked and transformed into chained Message’s, which is the AST that Ioke uses internally. Several other things were also done at this stage, including separating message chains on comma-borders. Most significantly the processing to put together interpolated strings and regular expressions happened at this stage. Sadly, the code to handle all that was complex, ugly, slow and frail. After this stage, operator shuffling happened. That part is still the same.

There were several problems I wanted to solve, but the main one was the ugliness of the algorithm. It wasn’t clear from the parser how an interpolated expression mapped into the AST, and the generated code added several complications that frankly weren’t necessary.

Ioke is a language with an extremely simple base syntax. It is only slightly more complicated than the typical Lisp parser, and there is almost no parser-level productions needed. So the new parser does away with the lexer/parser distinction and does everything in one pass. There is no need for lookahead at the token level, so this turns out to be a clear win. The code is actually much simpler now, and the Message AST is created inline in the new parser. When it comes to interpolation, instead of the semantic predicates and global stacks I had to use in the Antlr parser, I just do the obvious recursive interpolation. The code is simple to understand and quite efficient too.

At the end of the day, I did expect to see some performance improvements too. They turned out to be substantial. Parsing is about 2.5 times faster, and startup speed has improved by about 30%. The distribution size will be substantially smaller since I don’t need to ship the Antlr runtime libraries. And building the project is also much faster.

But the real gain is actually in maintainability of the code. It will be much easier for me to extend the parser now. I can do nice things to make the syntax more open ended and more powerful in ways that would be very inconvenient in Antlr. The error messages are much better since I have control over all the error states. In fact, there are only 13 distinct error messages in the new parser, and they are all very clear on what has gone wrong - I never did the work in the old parser to support that, but I get that almost for free in the new one.

Another thing I’ve been considering is to add reader macros to Ioke - and that would also have been quite painful with the Antlr parser generator. So all in all I’m very happy about the new parser, and I think it will definitely make it easier for the project going forward.

This blog post is in no way saying that Antlr is bad in any way. I like Antlr a lot - it’s a great tool. But it just wasn’t the right tool for Ioke’s syntax.

Got the following message in my inbox today:

All details (including registration) are available here.

Looking forward to see you there!

Technorati: glassfish rubyonrails jruby webinar

GlassFish v3 is opening up new frontiers by allowing to easily deploy Rails, Grails and Django applications, in addition to Java EE, without any additional packaging. You can even write a custom container to support new types of applications. Numerous entries on this blog have talked about how to deploy Rails applications on GlassFish v3. This Tip Of The Day (TOTD) will recap them and, once again, demonstrate how to easily get started with deploying some popular open source Rails applications on GlassFish v3.

Lets prepare a GlassFish v3 build for deploying Rails applications. This blog is going to use 9/16 nightly but you should pick the latest nightly or promoted.

1. Unzip the downloaded bundle as:

   ~/tools/glassfish/v3/9-16 >unzip ~/Downloads/glassfish-v3-b64-09_16_2009.zip

2. Configure JRuby/Rails in GlassFish v3 - JRuby/rails can be configured three different ways - use a previously installed JRuby/Rails directory, install JRuby/Rails module using the graphical Update Center or the "pkg" binary. This Update Center module comes packaged with JRuby 1.3.1, Rails 2.3.2 and some other useful gems. Pick the option you are most comfortable with and use it for your GlassFish installation.
   1. Configure previously installed JRuby/Rails directory as:

      ~/tools/glassfish/v3/9-16/glassfishv3/bin/asadmin create-jvm-options -Djruby.home=/Users/arungupta/tools/jruby
      Authentication failed with password from login store: /Users/arungupta/.asadminpass
      
      Enter admin password >
      created 1 option(s)
      Command create-jvm-options executed successfully.

      
      That's it!
   2. Install JRuby/Rails module using graphical Update Tool
      1. The graphical Update Tool tool can be invoked as:
         

         ~/tools/glassfish/v3/9-16/glassfishv3 >./bin/updatetool
         
         The software needed for this command (updatetool) is not installed.
         
         If you choose to install Update Tool, your system will be automatically
         configured to periodically check for software updates. If you would like
         to configure the tool to not check for updates, you can override the
         default behavior via the tool's Preferences facility.
         
         When this tool interacts with package repositories, some system information
         such as your system's IP address and operating system type and version
         is sent to the repository server. For more information please see:
         
         http://wiki.updatecenter.java.net/Wiki.jsp?page=UsageMetricsUC2
         
         Once installation is complete you may re-run this command.
         
         Would you like to install Update Tool now (y/n): y
         
         Proxy: Using system proxy settings.
         Install image: /Users/arungupta/tools/glassfish/v3/9-16/glassfishv3
         Installing pkg packages.
         Installing updatetool packages.
         Registering notifier: Already registered.
         Initialization complete.
         
         Software successfully installed. You may now re-run this command (updatetool).

      2. The first invocation of the command installs the Update Tool and the second invocation shows the following screen after "JRuby on GlassFish" module is selected:
         
         
         Click on green button in the top left to install the module and it picks up the dependencies as well as shown below:
         
         
         Click on "Install" to start the installation and click on "Accept" to accept the license.
      3. Close the Update Tool window once the installation is completed. The module creates "glassfish/jruby" directory.
   3. Install JRuby/Rails module using "pkg" binary
      1. Install the JRuby/Rails bits using the "pkg" binary. Invoke the command as:

         ~/tools/glassfish/v3/9-16/glassfishv3 >./bin/pkg
         
         The software needed for this command (pkg) is not installed.
         
         When this tool interacts with package repositories, some system information
         such as your system's IP address and operating system type and version
         is sent to the repository server. For more information please see:
         
         http://wiki.updatecenter.java.net/Wiki.jsp?page=UsageMetricsUC2
         
         Once installation is complete you may re-run this command.
         
         Would you like to install this software now (y/n): y
         
         Proxy: Using system proxy settings.
         Install image: /Users/arungupta/tools/glassfish/v3/9-16/glassfishv3
         Installing pkg packages.
         Initialization complete.
         
         Software successfully installed. You may now re-run this command (pkg).

      2. The command "pkg list -a" shows all the modules available for installation and the output looks like:
         
         

         ~/tools/glassfish/v3/9-16/glassfishv3 >./bin/pkg list -a
         NAME (PUBLISHER)                              VERSION         STATE      UFIX
         ant (contrib.glassfish.org)                   1.7.1-0.6       known      ----
         felix                                         2.0.0-0         installed  ----
         glassfish-appclient                           3.0-65          installed  ----
         glassfish-cmp                                 3.0-65          installed  ----
         
         . . .
         
         jersey-docs-and-examples                      1.1.2-1.0       known      ----
         jmaki (contrib.glassfish.org)                 1.8.1-2.0       known      ----
         jruby                                         1.3.1-1.1       known      ----
         jruby (contrib.glassfish.org)                 1.2.0-1.1       known      u---
         jruby-gems (contrib.glassfish.org)            2.3.2-1.1       known      ----
         jython-container (contrib.glassfish.org)      0.5.3-1.0       known      ----
         jython-runtime (contrib.glassfish.org)        2.5.0-1.0       known      ----
         metro                                         2.0-19          installed  ----
         
         . . .
         
         updatetool                                    2.3.0-36.2403   known      ----
         updatetool (contrib.glassfish.org)            2.2.2-30.2311   known      u---
         wxpython2.8-minimal                           2.8.10.1-36.2403 known      ----
         wxpython2.8-minimal (contrib.glassfish.org)   2.8.8-30.2311   known      u---

      3. Start the installation of "jruby" module as:
         
         

         ~/tools/glassfish/v3/9-17/glassfishv3 >./bin/pkg install jruby
         DOWNLOAD                                  PKGS       FILES    XFER (MB)
         Completed                                  2/2 14810/14810    37.0/37.0
         
         PHASE                                        ACTIONS
         Install Phase                            17273/17273

3. Redmine on GlassFish - Redmine is an open source project management web application. The simplified steps to deploy Redmine on GlassFish v3 are given below (also on GlassFish Gem and on GlassFish v3 TP2):
   1. Download and unzip Redmine 0.8.5 (latest stable release).
   2. Change the database adapter from "mysql" to "jdbcmysql" as:
      
      

      sed s/'adapter: mysql'/'adapter: jdbcmysql'/ <config/database.yml.new >config/database.yml

   3. Create the database manually as "sudo mysqladmin create redmine_development". "db:create" fails because of JRUBY-3502.
   4. Migrate the database as "db:migrate".
   5. Deploy the application as:

      ~/samples/jruby/redmine >~/tools/glassfish/v3/9-16/glassfishv3/bin/asadmin deploy redmine-0.8.5
       Authentication failed with password from login store: /Users/arungupta/.asadminpass
      
      Enter admin password>
      Command deploy executed successfully.

   6. Here are some snapshots from the deployed application:
      
      
      
      
      
      
4. Typo on GlassFish - Typo is the oldest Ruby on Rails blogware. The simplified steps to deploy Typo on GlassFish v3 are given below (also on GlassFish Prelude):
   1. Download and unzip Typo 5.3 (latest stable release).
   2. Change the database adapter from "mysql" to "jdbcmysql" as:
      
      

      sed s/'adapter: mysql'/'adapter: jdbcmysql'/ <config/database.yml.example >config/database.yml

   3. Create the database manually as "sudo mysqladmin create typo_dev". "db:create" fails because of JRUBY-3502.
   4. Typo runs using Rails 2.2.2 so lets install Rails 2.2.2 so lets install Rails 2.2.2 as:

      ~/samples/jruby/typo/typo-5.3 >~/tools/glassfish/v3/9-16/glassfishv3/glassfish/jruby/bin/jruby -S gem install rails -v 2.2.2
      JRuby limited openssl loaded. gem install jruby-openssl for full support.
      http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
      Successfully installed activesupport-2.2.2
      Successfully installed activerecord-2.2.2
      Successfully installed actionpack-2.2.2
      Successfully installed actionmailer-2.2.2
      Successfully installed activeresource-2.2.2
      Successfully installed rails-2.2.2
      6 gems installed
      Installing ri documentation for activesupport-2.2.2...
      Installing ri documentation for activerecord-2.2.2...
      Installing ri documentation for actionpack-2.2.2...
      Installing ri documentation for actionmailer-2.2.2...
      Installing ri documentation for activeresource-2.2.2...
      Installing ri documentation for rails-2.2.2...
      Installing RDoc documentation for activesupport-2.2.2...
      Installing RDoc documentation for activerecord-2.2.2...
      Installing RDoc documentation for actionpack-2.2.2...
      Installing RDoc documentation for actionmailer-2.2.2...
      Installing RDoc documentation for activeresource-2.2.2...
      Installing RDoc documentation for rails-2.2.2...

   5. Migrate the database as "db:migrate".
   6. Deploy the application as:
      

      ~/samples/jruby/typo >~/tools/glassfish/v3/9-16/glassfishv3/bin/asadmin deploy typo-5.3
      Authentication failed with password from login store: /Users/arungupta/.asadminpass
      
      Enter admin password>
      Command deploy executed successfully.

   7. Here are are some snapshots from the deployed application:
      
      
      
      
      
      
5. Substruct on GlassFish - Substruct is an open source E-Commerce project in Ruby-on-Rails. The simplified steps to deploy Substruct on GlassFish v3 are given below (also on GlassFish v3 Gem):
1. Download and unzip substruct 1.0 a6 (latest stable release).
2. Install the required gems as:

   ~/samples/jruby/substruct >~/tools/glassfish/v3/9-16/glassfishv3/glassfish/jruby/bin/jruby -S gem install RedCloth fastercsv mime-types mini_magick ezcrypto jruby-openssl --no-ri --no-rdoc

3. Change the database adapter from "mysql" to "jdbcmysql" as:
   
   

   ~/samples/jruby/substruct/substruct_rel_1-0-a6>sed s/'adapter: mysql'/'adapter: jdbcmysql'/ <config/database.yml
   >config/database.yml.new
   ~/samples/jruby/substruct/substruct_rel_1-0-a6>mv config/database.yml.new config/database.yml
   

4. Create the database manually as "sudo mysqladmin create substruct_development". "db:create" fails because of JRUBY-3502.
5. Initialize the database as:
   

   ~/samples/jruby/substruct/substruct_rel_1-0-a6 >~/tools/glassfish/v3/9-16/glassfishv3/glassfish/jruby/bin/jruby -S rake substruct:db:bootstrap

6. Deploy the application as:
   

   ~/samples/jruby/substruct >~/tools/glassfish/v3/9-16/glassfishv3/bin/asadmin deploy substruct_rel_1-0-a6
   Authentication failed with password from login store: /Users/arungupta/.asadminpass
   Enter admin password>
   
   Command deploy executed successfully.

7. Here is a snapshot of the deployed application:
   
   

So we deployed Redmine, Typo, and Substruct using JRuby/Rails on GlassFish without any additional packaging. There are several Rails applications deployed in production on GlassFish.