These notes apply to testing on a MAC OSX portable, and may or may not apply to your implementation. They are provided as an adjunct to my main Getting Gearman Going post elsewhere in this blog.

The project page for Java-Gearman-Service is located [HERE] on Google Code.

The full set of instructions for staring up Gearman’s Java-Gearman-Service were not clearly linked to the main Gearman project page, so I’m including the link [HERE] to save you the few Google dorkings I did to find it.

Starting up the Java service should be as simple as this:


java -jar java-gearman-service-0.6.6.jar


HOWEVER, I received this instead.. an error:


david$ java -jar java-gearman-service-0.6.6.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/gearman/impl/Main : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)


Checking my version shows that I am on 1.6 not 1.7 as I had thought;


david$ java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06-451-11M4406)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01-451, mixed mode)


To get the proper version, I navigated to the Oracle page located [HERE], agreed to their terms (do I really have a functional choice… not if I want/need to use Java…) and pushed forward.

If you are running the install for 1.7, you should see a dialog like this:

That has at least resolved this part of the issue, and will attempt to restart the server.


david$ java -version
java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b12)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)


Now I’m going to restart, specific a custom port and get it kicked off in the background:


david$ java -jar java-gearman-service-0.6.6.jar -p6315 &


At this point the process is running on my Job Service box and next step will be to craft some code to see how it all works.