Programming language and runtime environment that allows compiled Java programs to run unchanged on most hardware and software platforms
Questions tagged [java]
1835 questions
20
votes
5 answers
What is better for a Java Web Application: more CPU cores or a higher clock speed?
I'm not sure whether serverfault is the right place to ask this, but I wonder what choice you would make if you had to select a new CPU type for your Java Web Application:
a) a CPU with 32 cores and clock speed 2.5 Ghz
or
b) a CPU with 8 cores but…

bzero
- 399
- 2
- 9
19
votes
8 answers
How to change default /tmp to /home/user/tmp
Is there an environment variable to set the temporary directory on debian based systems?
I have a java applet that uses that environement variable and it's getting confused when launching two instances of the same applet.

Disco
- 1,421
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17
votes
2 answers
Adding lines to /etc/profile with puppet?
I use puppet to install a current JDK and tomcat.
package {
[ "openjdk-6-jdk", "openjdk-6-doc", "openjdk-6-jre",
"tomcat6", "tomcat6-admin", "tomcat6-common", "tomcat6-docs",
"tomcat6-user" ]:
ensure => present,
}
Now I'd like…

miku
- 445
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16
votes
3 answers
Unable to change vm.max_map_count for elasticsearch
Prehistory
I have elasticsearch and SugarCRM7 running on CentOS 6.5. Every day I face the same problem: java outOfMemory error. That happens because of small vm.max_map_count value, 65530 only when 262144 is recommended.
Problem
The problem is that…

Valentina
- 161
- 1
- 1
- 3
16
votes
3 answers
How do you manage Java in your Windows/Active Directory environment?
Like I suppose a lot of people, we have a Windows/Active Directory environment and a lot of internal line of business apps that require Java. Our experience is that Java does not play nice in such a corporate network environment. Initial…

Maximus Minimus
- 8,987
- 2
- 23
- 36
15
votes
4 answers
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 opened for user adtech by root(uid=0)
su:…

quanta
- 51,413
- 19
- 159
- 217
14
votes
2 answers
Installing openjdk 11 on alpine:3.9
I'm trying to build an alpine docker image with openjdk 11. To do so, I'm starting an alpine container:
docker run -it alpine:3.9 /bin/sh
And running the following:
export JAVA_HOME=/opt/openjdk-11
export PATH=$JAVA_HOME/bin:$PATH
export…

Thiago
- 287
- 1
- 2
- 7
14
votes
1 answer
Copy a Java keystore on one machine to another?
I have a keystore on one machine (at /root/.keystore) and I want to move it to another machine at the same location. Currently, the second machine doesn't have a keystore at /root/.keystore, is there a way I can export then create/import? Or do I…

Brandon
- 247
- 1
- 2
- 6
13
votes
6 answers
Open source tomcat log viewer
I'm managing several tomcat instances (aprox 30-35) and looking for some console to centralize the logs.
I tried php-syslog-ng before (no with tomcat), and found it useful. I would like that these software would have some of these features:
-Syntax…
Ari
13
votes
5 answers
Set JDK 8 as the default Java on Debian 8
I'm trying to set the Java SDK 8 tools (installed from the debian backports repo) as the defaults.
# update-java-alternatives --list
java-1.7.0-openjdk-amd64 1071 /usr/lib/jvm/java-1.7.0-openjdk-amd64
java-1.8.0-openjdk-amd64 1069…

Edd Barrett
- 963
- 3
- 9
- 20
13
votes
1 answer
Suddenly error='Cannot allocate memory' (errno=12)
So this morning I noticed my website is down, went on my server and saw that the webserver has been stopped.
When I try to start it again I get this error
start -Dhttp.port=80 -Dapplication.secret=**********
[info] Wrote…

Jakob Abfalter
- 245
- 1
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- 8
13
votes
4 answers
ps aux hanging on high cpu/IO with java processes
I'm having some issues with java process and nrpe checks. We have some processes that sometimes use 1000% cpu on a 32 core system. The system is pretty responsive until you do a
ps aux
or try to do anything in the /proc/pid#…

Mike
- 22,310
- 7
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- 79
13
votes
4 answers
How to convince my Administrator that Java ON A SERVER is not insecure per se?
The Application
We have a small Java application which uses some Camel routes to pick up uploaded files from a webserver, process them and send out some e-mails with the results.
The server on which this application was running has been…

lajuette
- 771
- 6
- 16
13
votes
7 answers
Run Jar in Background on Linux
I have a jar that runs forever (infinite loop with socket listening thread) and need it to run in the background at all times. An example would be: "java -jar test.jar" How do I do this? Thanks in advance!

Benny
- 371
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- 12
12
votes
4 answers
Java error Unsigned application requesting unrestricted access to system
I want to reboot a server, so I opened its Integreted Dell Remote Access Controller in Chrome, and clicked on "start virtual console", which caused Chrome to download a file with a strange name. The file opened in Java Web Launcher, which (after a…

Geek2Sages
- 121
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