Submitting a Java universe job

What is the Java universe?

This is a good point for your tutorial leader to jump in and describe to you the Java universe. Strictly speaking, the Java universe is not necessary because you can use the vanilla universe for Java jobs. However, we discovered that life can get complicated sometimes. For instance, how can Condor tell if a job exited normally but with an error code, or if the Java virtual machine exited abnormally due to a problem with the computer? Condor should act differently in these two cases: if the JVM is bad, another computer can be tried, but if the job failed, that's the fault of the author.

The Java universe addresses this problem, among others, as your tutorial leader will describe to you. There is a really wonderful paper about grid computing and the Java universe, and I can't recommend the paper highly enough. You should read this paper.

Douglas Thain and Miron Livny, "Error Scope on a Computational Grid: Theory and Practice", Proceedings of the Eleventh IEEE Symposium on High Performance Distributed Computing (HPDC11), Edinburgh, Scotland, July 2002. Postscript PDF

Creating a Java program

First you need a Java program. Here's one to start you off. Save it in a file named

public class simple
    public static void main(String[] args)
        if (args.length != 2) {
            System.out.println("Usage: <sleep-time> <integer>");
        Integer arg_sleep_time;
        Integer arg_input;

        arg_sleep_time = new Integer(args[0]);
        arg_input      = new Integer(args[1]);

        int sleep_time;
        int input;
        sleep_time = arg_sleep_time.intValue();
        input      = arg_input.intValue();

        try {
            System.out.println("Thinking really hard for " + sleep_time + " seconds...");
            Thread.sleep(sleep_time * 1000);
            System.out.println("We calculated: " + input * 2);
        } catch (InterruptedException exception) {

Then compile and try out the program:

nova 1%  javac

nova 2%  ls -lh simple.class
-rw-r--r--    1 alainroy math         1008 Dec 20 04:01 simple.class

nova 3%  java simple 4 10
Thinking really hard for 4 seconds...
We calculated: 20

Submitting a Java job

Create a submit file. Note that in the arguments, the first argument is "simple", which is the name of the class you want to invoke. Skipping this argument is a common mistake.

Universe   = java
Executable = simple.class
Arguments  = simple 4 10
Log        = simple.log
Output     = simple.out
Error      = simple.error

Now submit your job:

nova 4% rm simple.log

nova 5% condor_submit
Submitting job(s).
Logging submit event(s).
1 job(s) submitted to cluster 6088.

nova 6% condor_q -sub alainroy

-- Submitter: : <> :
 ID      OWNER            SUBMITTED     RUN_TIME ST PRI SIZE CMD               
6088.0   alainroy       12/20 04:05   0+00:00:01 R  0   0.0  simple.class simpl

nova 7%  condor_q -sub alainroy

-- Submitter: : <> :
 ID      OWNER            SUBMITTED     RUN_TIME ST PRI SIZE CMD               

0 jobs; 0 idle, 0 running, 0 held

nova 8%  cat simple.log
000 (6088.000.000) 12/20 04:05:38 Job submitted from host: <>
001 (6088.000.000) 12/20 04:05:46 Job executing on host: <>
005 (6088.000.000) 12/20 04:05:51 Job terminated.
        (1) Normal termination (return value 0)
                Usr 0 00:00:00, Sys 0 00:00:00  -  Run Remote Usage
                Usr 0 00:00:00, Sys 0 00:00:00  -  Run Local Usage
                Usr 0 00:00:00, Sys 0 00:00:00  -  Total Remote Usage
                Usr 0 00:00:00, Sys 0 00:00:00  -  Total Local Usage
        0  -  Run Bytes Sent By Job
        0  -  Run Bytes Received By Job
        0  -  Total Bytes Sent By Job
        0  -  Total Bytes Received By Job

Congratulations, you've submitted a Java job to Condor!

Java on your Condor pool

Condor keeps track of which computers have a functional Java virtual machine and which version it is. You can find this out by using condor_status:

nova 9% condor_status -java

Name          JavaVendor  Ver    State      Activity   LoadAv Mem   ActvtyTime

abel-01.cs.ta Blackdown J 1.4.1  Claimed    Busy       1.230   494  0+00:16:46
abel-03.cs.ta Blackdown J 1.4.1  Unclaimed  Idle       0.150   494  0+03:15:00
abel-05.cs.ta Blackdown J 1.4.1  Unclaimed  Idle       0.060   494  0+01:10:04

Extra credit We don't yet java checkpointing for Java. In the past we implemented it and found it to be unusably slow. Your tutorial leader can fill you in on the details. However, Java has something similar to the remote I/O provided by the standard universe. You can read about the Java universe and Chirp I/O to learn more.

Next: Coordinating a set of jobs: A simple DAG