#247 Problems running multiple instances on same system
DrJava is used extensively by our Computer Science department for teaching introductory programming classes for CSCI Majors. We've recently run into an odd problem with it.
We have a shared remote access Linux system which allows multiple users to run drjava off the same server. We are using the NX server and client provided by nomachine.com. On several occasions, when a class of students all try to run DrJava on the same system, most of the drjava processes start, but then hang, and never open the GUI. After other running DrJava processes are quit, then eventually other students can run DrJava. This doesn't always occur, but has happened several times. I'm not sure what would cause such a thing to happen. I tried running strace on drjava to try to see what it was getting hung up on, but didn't find anything. DrJava works fine on any of the Linux lab systems that are configured the same, but they only have one user on them at a time.
Any idea on what might be happening or how I should go about trying to figure out what is happening?
System Properties:
DrJava Version drjava-20090821-r5004
DrJava Build Time 20090821-1520
drjava.debug.port = 48072
java.runtime.name = OpenJDK Runtime Environment
sun.boot.library.path = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64
java.vm.version = 14.0-b16
java.vm.vendor = Sun Microsystems Inc.
java.vendor.url = http://java.sun.com/
path.separator = :
java.vm.name = OpenJDK 64-Bit Server VM
file.encoding.pkg = sun.io
sun.java.launcher = SUN_STANDARD
user.country = US
sun.os.patch.level = unknown
java.vm.specification.name = Java Virtual Machine Specification
user.dir = <anonymized user.dir>
java.runtime.version = 1.6.0_0-b16
java.awt.graphicsenv = sun.awt.X11GraphicsEnvironment
java.endorsed.dirs = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/endorsed
os.arch = amd64
javax.accessibility.assistive_technologies = org.GNOME.Accessibility.JavaBridge
java.io.tmpdir = /tmp
line.separator = "\u000a"
java.vm.specification.vendor = Sun Microsystems Inc.
os.name = Linux
sun.jnu.encoding = UTF-8
java.library.path = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64/server:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/amd64:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/../lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
java.specification.name = Java Platform API Specification
java.class.version = 50.0
sun.management.compiler = HotSpot 64-Bit Server Compiler
os.version = 2.6.30.9-102.fc11.x86_64
user.home = <anonymized user.home>
user.zoneinfo.dir = /usr/share/javazi
user.timezone = America/Chicago
java.awt.printerjob = sun.print.PSPrinterJob
file.encoding = UTF-8
java.specification.version = 1.6
java.class.path = /opt/drjava-20090821/drjava-stable-20090821-r5004.jar
user.name = <anonymized user.name>
java.vm.specification.version = 1.0
java.home = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre
sun.arch.data.model = 64
user.language = en
java.specification.vendor = Sun Microsystems Inc.
java.vm.info = mixed mode
java.version = 1.6.0_0
java.ext.dirs = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/ext:/usr/java/packages/lib/ext
sun.boot.class.path = /usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/resources.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/rt.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/sunrsasign.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/jsse.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/jce.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/charsets.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/lib/rhino.jar:/usr/lib/jvm/java-1.6.0-openjdk-1.6.0.0.x86_64/jre/classes
java.vendor = Sun Microsystems Inc.
file.separator = /
java.vendor.url.bug = http://java.sun.com/cgi-bin/bugreport.cgi
sun.io.unicode.encoding = UnicodeLittle
sun.cpu.endian = little
java.rmi.server.hostname = 127.0.0.1
sun.cpu.isalist =
#DrJava configuration file
#Wed Feb 03 15:48:51 CST 2010
javac.location = /usr/lib/jvm/java/lib/tools.jar
key.delete.next = [shift DELETE]
key.delete.previous = [shift BACK_SPACE]
window.height = 974
window.width = 1280
window.x = 0
window.y = 25
last.dir = <anonymized user.home>
last.interactions.dir = <anonymized user.home>
tabbedpanes.state = 640 512 700 400
dialog.drjava.survey.enabled = false
new.version.notification.last = 1265233693635
drjava.survey.notification.last = 1258060798352
drjava.survey.result.last = http://www.drjava.org/submit-usage.php?rev=5004&os.name=Linux&os.version=2.6.30.8-64.fc11.x86_64&java.version=1.6.0_0&java.vendor=Sun%20Microsystems%20Inc.
Used memory: about 72.02 megabytes
Free memory: about 166.48 megabytes
Total memory: about 238.50 megabytes
Total memory can expand to: about 3.46 gigabytes
Number of processors/cores: 8
