JVM (Java Virtual Machine) is an abstract computing machine (or virtual machine), a platform-independent execution environment that converts Java bytecode into machine language and executes it.

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JVM Memory Consumption

I am trying to run tomcat on a low memory system (150-256Mb). Even though I start the JVM with -Xmx64m (which should be the default anyway), the process immediately takes up 200Mb+. I wonder why the ...
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Cannot switch, ssh to specific user: su: cannot set user id: Resource temporarily unavailable?

/var/log/secure: su: pam_keyinit(su-l:session): Unable to change UID to 500 temporarily su: pam_keyinit(su-l:session): Unable to change UID to 500 temporarily su: pam_unix(su-l:session): session ...
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4answers
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which JVM is best for Tomcat?

I have Tomcat 6.0 up and running. I went to tweak the memory sizes and realized that I have it running on the Sun JDK 1.6 client JVM. I don't have the Sun server JVM installed: C:\>java -client ...
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5answers
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How can I monitor memory usage for a windows-based JVM and trigger an alert if it gets too high?

I have an app that runs as a JVM in Windows 2008. I'd like to monitor it's memory usage and be sent an email if/when memory usage reaches a specific threshold. Is there a free utility or method for ...
5
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5answers
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How to reliably take Java Heap Dumps?

My team is running into difficulties when trying to take good heap dumps triggered by OutOfMemoryErrors. For specific reasons we are currently taking the dumps with jmap called from a bash script ...
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4answers
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Constantly Increasing swap size in Linux and Swap space not being reclaimed?

I have a 8GB RAM linux box on which 4 tomcat servers are running. One of the them is set to 3000MB memory(jvm -Xms and -Xmx setting) and others are set to 1500MB. The swap partition is also set to ...
4
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5answers
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Tracing slow Java I/O in Solaris 10

We have a Java application which is significantly slower in Solaris 10 server than in Windows PC. We have profiled (-Xprof) the application and observed that UnixFileSystem.getBooleanAttributes0 ...
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3answers
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Java VM problem in OpenVZ

I bought a vps for hosting my java needs. But I can't run java on it. Everything about java is correctly installed but when I try to run java ("java -version" forexample) I get this error : Error ...
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2answers
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Which performance metrics to monitor on a JVM?

I want to do some performance monitoring on our JVMs. What would be interesting to monitor besides the obvious things I already have on my list ? JVM Free/Total memory GC rate (how many per minute) ...
3
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1answer
254 views

SysRq, task list and missing processes

I've been troubleshooting a pretty difficult issue on Linux where a JVM appears to hang. As part of the investigation, I've been trying to capture the list of current tasks and their state using one ...
3
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2answers
2k views

Performance problems when running Java desktop applications on Citrix Metaframe

We have a desktop Java application running within a Citrix Metaframe server farm and the performance, specially while starting up the app, is very unreliable. Sometimes it takes 15 seconds and ...
3
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1answer
97 views

How to determine what websites or local applications are using JVM/JRE

We run a large Windows shop -- tens of thousands of workstations. Most have a version of the Sun/Oracle Java Virtual Machine (JVM) installed. With all the security issues around the JVM, we'd like to ...
3
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1answer
389 views

What are the best practices for monitoring and alerting for low level JVM metrics?

I'm looking to set up monitoring and alerting for java server based app and want to find some best practices for monitoring JVM specific metrics and for designing alerts based on those metrics. So ...
2
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2answers
2k views

Deploy Jetty as port 80 daemon on Linux

I'm curious what techniques you Linux admin gods are using to manage your Jetty deployments. I come from a Windows Server background so I'm still getting used to all of this. I've been looking for a ...
2
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5answers
1k views

Tools and Tips for Sun JVM Troubleshooting

We run a cluster of ColdFusion 8 servers on top of the Sun JVM, version 1.6.0_11. Occasionally a server will simply stop responding to requests. We've determined so far that the JVM is locking up ...
2
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1answer
228 views

Glassfish Server JVM Tunning

I need to setup a Oracle Glassfish Server and after some research I came up with a configuration that I would like to propose. Any suggestions and/or corrections are very welcome. My Hardware/OS ...
2
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1answer
894 views

how to solve out of memory error in java in amazon ec2 server

can anyone explain about this error message? we are using IBM jre to run java application Its occupying more space on the server. JVMDUMP006I Processing dump event "systhrow", detail ...
2
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0answers
287 views

Tuning Tomcat 7 on windows (for Alfresco)

I have installed Tomcat7 as a service on a windows server 64bit 2008 R2 to run Alfresco (4.2.c). I have 48G of ram. I have read Tomcat tuning tutorial with the JVM settings for memory. To edit the ...
2
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1answer
261 views

Amazon Ec2 segfault error

I have a production Java application hosted on Jetty. During the last week or so, the system has crashed, leaving only a single message accessed with "dmesg": java[20551]: segfault at ...
2
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1answer
219 views

Environment variables and further user setup

I have a jar file, which works in many machines. However we just asked for a new unix user to install it, and it is not behaving the same... wonder if it could be anything related to some env. var. ...
2
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3answers
2k views

Installing Java Runtime for a Server: Something better than std JRE package?

I need to install a Java runtime on server machines. The JRE package from Sun acts as if I'm running on a client machine -- it installs WebStart, Auto Updating, probably browser hooks, and other ...
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2answers
295 views

finding a linux distribution that will run on sparc cpu

We have a server that runs on Solaris using the sparc CPU. What we want to do is run linux on sparc. Is there any distribution that will allow linux to run on a sparc CPU? The reason is because we ...
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2answers
557 views

Linux out of memory on VPS

On my VPS (CentOS) 4GB ram (2 + 2 dynamically assigned when needed) and i have tomcat running with following options JAVA_OPTS="-Xms256m -Xmx2048m -XX:MaxPermSize=256m". Now when i try to start ...
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3answers
315 views

What JVM are you using with ColdFusion 8.01 and Windows 2003?

I have CF 8.01 on Windows 2003 (both 64 bit and 32 bit versions). I need to do some performance tuning on the JVM but wanted to start with what the community thought was the best JVM. In a production ...
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1answer
1k views

jvm performance tuning tips / resources?

My experience with the jvm has mostly been maintain a tomcat container for several applications. I find myself always not sure of the what ratio of -Xms -Xmx -Xmn -XX:PermSize -XX:MaxPermSize ...
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1answer
6k views

add-apt-repository: command not found in Ubuntu 10.04

I installed my VPS with Ubuntu 10.04 64 bit and I even checked with cat /etc/lsb-release and I got DISTRIB_ID=Ubuntu DISTRIB_RELEASE=10.04 DISTRIB_CODENAME=lucid DISTRIB_DESCRIPTION="Ubuntu ...
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1answer
2k views

JVM tuning in JBOSS AS 7

Can anyone explain as to where and how do I configure the following JVM parameters to tune JBOSS. I am using the latest JBOSS AS 7. I am using openJDK-6 on Linux. The following are the parameters ...
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1answer
1k views

Jenkins (JVM) crashes after few minutes after start

Host OS: OpenVZ host Guest OS: Debian 6.0 minimal Java: java6 sun Servlet container: Winstone Jenkins for debian: http://pkg.jenkins-ci.org/debian/ Jenkins version: 1.449 uname -a: Linux hostname ...
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2answers
847 views

Performance issue with JVM (1.6.0_22) invoking OS command on Solaris 10

My high-level problem is my build tool (Maven) which became suddenly very slow on a Solaris 10 environment. A build which was taking 8 minutes now takes 50 minutes. I narrowed this problem down to a ...
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1answer
2k views

Weblogic administration console way too slow

I've installed weblogic 10.3.3, configured simple domain with default configuration. And after starting weblogic I cannot use it via admin console because it is starting too slow (~10 mins). It seems ...
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2answers
325 views

Running Java on VPS environment

I have been advised by my friend that when running Java on virtual environment, it can suck RAM quite drastically over time and adding more RAM won't make any difference. Is this true? Why is this ...
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1answer
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fork: Resource temporarily unavailable running JVM

I'm running a Tomcat 6 instance on a 34 GB EC2 instance. I've been struggling to keep the memory down but this thing services a lot of requests and the heap frequently gets up to 13 GB. But the heap ...
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2answers
1k views

JVM memory initializazion error after windows update

We have three Windows Server 2003 with 2 GB RAM. Server1 tomcat 5.5.25 jvm version SUN 1.6.0_11-b03 Server2 tomcat 5.5.25 jvm version SUN 1.6.0_14-b08 ...
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4answers
559 views

Linux distro designed to run a Java service?

Is there a 64-bit linux distro available that is made to run a Java JVM inside of it? What I mean, is that it would be nice to have a simpler distribution of Linux that is small and fast to setup ...
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2answers
381 views

Non-heap memory leak JVM

I have a glassfish v4.0 set up on Ubuntu server running on oracle java virtual machine and jvm process resident memory size (got via "top" command) grows up until jvm doesnt have memory to create new ...
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1answer
127 views

Swap space maxing out - JVM dying

I have a server running 3 WordPress instances, MySql, Apache and the play framework 2.0 on 64m initial & max heap. If I increase the max heap of the JVM that play is running in even by 16m I see ...
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2answers
363 views

Coldfusion multiserver instance hangs

I have a coldfusion 8 multiserver setup with IIS in Windows 2008 Standard SP2 and when one instance "hangs" (I can't connect to the instance from fusion reactor) the web server throws a "503 service ...
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2answers
1k views

Glassfish V3 using up all available memory

I have a Virtual Server with 1GB of RAM. When i start glassfish with asadmin start-domain it instantly allocates all available memory, although i defined -Xmx128m in my domain.xml. Am I missing an ...
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0answers
30 views

Tomcat Memory - Setting in setenv.sh not respected

I have Tomcat 7.0.35 on CentOS. I have configured setenv.sh to have the following: export JAVA_OPTS="-Dfile.encoding=UTF-8 -Xms128m -Xmx1024m -XX:PermSize=256m -XX:MaxPermSize=512m" However under ...
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1answer
233 views

JVM crash with segmentation fault

We have a cluster of tomcat servers, just upgraded to debian7/openjdk7/tomcat7 (all from stock debian). Now we had two JVM crash on different machines. Both servers having identical hardware and are ...
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0answers
52 views

Committed memory on my tomcat server

I have a problem to configure JVM on my server. The server is a machine runs on AWS with 8G of RAM and 8 CPU. There is only tomcat6 with solr on the server. Actually I have configured JVM like that: ...
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0answers
47 views

Authenticate JMX to Active Directory on Linux [closed]

Is it possible to have a Linux JVM use Active Directory for JMX authentication?
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1answer
467 views

Migrating WebLogic 10.3.0 to new host. Slow managed server startup times

We are migrating our Blue Martini Commerce application (only supported on WebLogic 10.3.0) to a new host (Redhat 6.3 on a VMWare ESX vm). We are seeing extremely slow start up times for our managed ...
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0answers
174 views

what is the default size of jvm heap when using maven to create jvm?

I am using the server started by the following command. mvn jetty:run i want to stop the server, but i failed to run mvn jetty:stop, even faild to run java -version, why? [mirror@home wpse]$ mvn ...
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1answer
195 views

Reduce Tomcat6 memory footprint

This is my setenv.bat (windows installation). It's the MySQL enterprise monitor service manager. set JAVA_HOME=D:\MYSQL_~2\SERVIC~1\java set JAVA_OPTS= ++JvmOptions="-XX:+UseParallelOldGC" ...
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0answers
157 views

How to make glassfish v3.1.1 run with -Xmx256m?

I have a t1.micro amazon instance and that machine have very scarce resources. I need for the moment to run glassfish3.1.1 (due to complete JEE6 support) on those conditions. Any guidance is welcome. ...
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1answer
62 views

How to increase heap size for particular WAR on WAS?

I have a WAS where a particular WAR file is deployed. This WAR file runs okay most of the time, however at times it would run to Java OOM issue. I'd like to know if there is any control to increase ...
0
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1answer
530 views

how do i detect which version 32 or 64 bit Java is installed in Centos?

I am trying to detect which version of the java is running in my system (i mean i want to find out whether my java installation is 32 bit or 64 bit) I have tried $java -version which outputs ...
0
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1answer
964 views

How to monitor Java memory Usage or Heap Size via Hyperic Monitoring

I was trying to configure the JVM memory usage, Heap Size and Logs monitoring via Hyperic Tool. But the documentation is not much clear how to do that. Is anybody can guide me please.
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5answers
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Fastest OS for Java applications

I have a multithreaded Java program. I am dealing with certain perfomance problems. I have improved everything. Hardware + Software. Now I think that it's time to move to proper Operating System. I ...