[dev-ruby] "JRubyOnRails Blames ActiveRecord" *ing: culprit Cucumber, inspector JConsole

I was working on JRubyOnRails project, where we used Cucumber in providing a web-app feature that required functional testing of some web portals.

Scenario: 
     In this Rails application, 'Cucumber' tests for different web-portals are invoked every scheduled interval using 'derailed_cuke' and then the test results are processed and saved in a MySQL database.

Gems Used:
     #for Rails3
          'rails', '3.0.3'
     #for MySQL ActiveRecord
          'activerecord-jdbcmysql-adapter', '1.0.2'
          'activerecord-jdbc-adapter', '1.0.2'
          'jdbc-mysql', '5.0.4'
     #for Cucumber
          'cucumber', '0.10.0'
          'cucumber-rails', '0.3.2'

          'gherkin', '2.3.3'

     #with JRuby version 1.5.5

Exception:

• After starting Rails Server and waiting for some non-specific time, an exception started arising mentioning ActiveRecord and an Heap OutOfMemory Exception being raised.
• I checked for my database services, schema & content; all was as expected and even working fine from 'rails console'.

Action:

• My bad old debug-style... the first thing I did was inserted 'print STATUS_MSG' at all suspected locations for ActiveRecord.
• It worked :), and the location sorted out was the place where cucumber-tests' processed results was saved in database.
• So now, 'Cucumber' was under suspicion radar... I google-d over recent incidents including both 'OutOfMemory Exception' and 'Cucumber', and there were few blogposts about similar problem of 'memory leakage' in Cucumber.

     I had a JConsole window already fired-up and profiling the Memory level changes
     in my JRubyOnRails appication (one of the major benefit of using JRuby).

• So, I started tweaking the Cucumber test's schedule interval to a higher and lower value.
  This clearly showed it's impact over the Memory Profiling by JConsole and the relativity of duration in which the Exception was being raised.

Solution:

     Until the Cucumber flaw is corrected, the work-around used was

        [] pushing in some more RAM
        [] using JVM Parameters to increase the Heap Size used by Rails application
         #jruby -J-Xmx2500m -J-Xms2500m -J-Xmn512m -S rails s
             here,
                  -J-Xmx2500m ~ means maximum Java Heap Size increased to 2500m
                  -J-Xms2500m ~ means initial Java Heap Size increased to 2500m
                  -J-Xmn2500m ~ means eden Java Heap Size increased to 500m
                  for server-side applications, Xmx & Xms is preferred to be kept same

[dev-ruby] 'gherkin' need a native install AND I ported entire jruby dir

When I started working on 'derailed_cuke', I was newbie at 'Cucumber' and it's dependency list included 'Gherkin'... I was using JRuby.

[[ derailed_cuke ]] 
this project is a simple way to use cucumber tests independent of any Rails using Ruby's Rake.

Due to some reasons... I copied this project on another machine along-wth entire JRuby-Pack from older machine.
Now, this JRuby-Pack of mine from older machine already had all the gems installed in it and was kin'of a portable setup with script declaring environment variables for '$JRUBY_HOME' & '$JRUBY_HOME\bin' to be added to $PATH.

I setup JRuby-Pack & started the application 'derailed_cuke'. There was the error for gem 'gherkin' of not being present.
But, I had it installed on earlier machine when I got Cucumber installed.

I called in 'gem install gherkin' again to make-up for whatever have been missing.
Installation Successful. But still a 'gherkin' error was there. Running 'gem list' showed that now I had two versions of gherkin installed.

Looking a more into issue, resolved it as:

[*] the newest version just installed wasn't desired by Cucumber,

[*] the version desired by Cucumber was copied from another box and,

[*] 'gherkin' requires a 'Native Install' 

*** thus do a clean 'bundle install' to avoid such newbie mistakes

So, doing a native install of specific 'gherkin' gem was required.