JMX::MBeans.parent_for unreliable in Jruby 9000

[savelandr]

test.rb:

require 'jmx'

client = JMX.connect(:host => 'localhost', :port => 9999)
puts client["JMImplementation:type=MBeanServerDelegate"].attributes

Running in JRuby 1.7:

$ rbenv global jruby-1.7.14 
$ ruby -J-Dcom.sun.management.jmxremote -J-Dcom.sun.management.jmxremote.port=9999 -J-Dcom.sun.management.jmxremote.authenticate=false -J-Dcom.sun.management.jmxremote.ssl=false test.rb
MBeanServerId
SpecificationName
SpecificationVersion
SpecificationVendor
ImplementationName
ImplementationVersion
ImplementationVendor

Running in JRuby 9000:

$ rbenv global jruby-9.0.3.0 
$ ruby -J-Dcom.sun.management.jmxremote -J-Dcom.sun.management.jmxremote.port=9999 -J-Dcom.sun.management.jmxremote.authenticate=false -J-Dcom.sun.management.jmxremote.ssl=false test.rb
ArgumentError: Java package `javax' does not have a method `const_set'
       method_missing at uri:classloader:/jruby/java/java_package_module_template.rb:13
  block in parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:20
                 each at org/jruby/RubyArray.java:1560
               inject at org/jruby/RubyEnumerable.java:895
           parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:12
             generate at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbean_proxy.rb:30
                   [] at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/server.rb:46
                <top> at test.rb:4

I also have similar problems when the ObjectName's class name is "com.x.y.z". And I can easily force the issue by just calling Java::Com or Java::Sun before accessing an ObjectName whose class name path is sun.x.y or com.x.y.

I.e.

require 'jmx'

Java::Sun
client = JMX.connect(:host => 'localhost', :port => 9999)
puts client["java.lang:type=Memory"].attributes

results in

$ rbenv global jruby-9.0.3.0 
$ ruby -J-Dcom.sun.management.jmxremote -J-Dcom.sun.management.jmxremote.port=9999 -J-Dcom.sun.management.jmxremote.authenticate=false -J-Dcom.sun.management.jmxremote.ssl=false test.rb
ArgumentError: Java package `sun' does not have a method `const_set'
       method_missing at uri:classloader:/jruby/java/java_package_module_template.rb:13
  block in parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:20
                 each at org/jruby/RubyArray.java:1560
               inject at org/jruby/RubyEnumerable.java:895
           parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:12
             generate at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbean_proxy.rb:30
                   [] at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/server.rb:46
                <top> at test.rb:5

but this doesn't force the problem in JRuby 1.7, it still prints the attributes for that object name.

[savelandr]

Actually, a simpler demonstration that doesn't require launching the JVM with JMX available:

test.rb:

require 'jmx'

Java::Sun
puts JMX::MBeans.parent_for "sun.something.SomethingElse"

JRuby 1.7:

$ rbenv global jruby-1.7.14 
$ ruby test.rb 
JMX::MBeans::Sun::Something
SomethingElse

JRuby 9000:

$ rbenv global jruby-9.0.3.0 
$ ruby test.rb 
ArgumentError: Java package `sun' does not have a method `const_set'
       method_missing at uri:classloader:/jruby/java/java_package_module_template.rb:13
  block in parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:20
                 each at org/jruby/RubyArray.java:1560
               inject at org/jruby/RubyEnumerable.java:895
           parent_for at /home/saveland/.rbenv/versions/jruby-9.0.3.0/lib/ruby/gems/shared/gems/jmx-0.9/lib/jmx/mbeans.rb:12
                <top> at test.rb:4

[tobias]

I'm not sure if it's the same issue, but #16 may fix this as well.

[enebo]

@tobias @savelandr sure seems like the same issue you had.

[savelandr]

@tobias @enebo

Yup, this does fix it. I tried the simple example as well as running Ruby with JMX enabled so the test connects to itself. Thanks!

[enebo]

@savelandr thanks for checking!