SUNScholar/Prepare Ubuntu/S08

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Step 8.1 Java environment settings for Tomcat webapp server

To setup the environment variables for Tomcat java web applications, type the following:

sudo nano /etc/default/tomcat6

Check the following for comparison:

# You may pass JVM startup parameters to Java here. If unset, the default
# options (-Djava.awt.headless=true -Xmx128m) will be used.
#JAVA_OPTS="-Djava.awt.headless=true -Xmx128m"
JAVA_OPTS="-Djava.awt.headless=true -Xms1024m -Xmx2048m -XX:MaxPermSize=1024m"

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NANO Editor Help

CTL+O	= Save the file and then press Enter
CTL+X	= Exit "nano"
CTL+K	= Delete line
CTL+U	= Undelete line
CTL+W	= Search for %%string%%
CTL+\	= Search for %%string%% and replace with $$string$$
CTL+C	= Show line numbers

More info = http://en.wikipedia.org/wiki/Nano_(text_editor)

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Java environment settings used for SUNScholar

Your settings will depend on how much RAM you have available to assign to the Tomcat server. See graph below as well.

JAVA_OPTS="-Djava.awt.headless=true -Xmx8192m -Xms4096m -XX:PermSize=4096m -XX:MaxPermSize=8192m"

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Graph of RAM memory usage on SUNScholar.

Step 8.2 Java environment settings for other java web applications

To setup the environment variables for other java applications (such as the Handle and SOLR servers), type the following:

sudo nano /etc/environment

Copy and paste the following to the bottom of the file.

JAVA_HOME="/usr/lib/jvm/default-java"
JAVA_OPTS="-Djava.awt.headless=true -Xmx1024m -Xms512m -Dfile.encoding=UTF-8"

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NANO Editor Help

CTL+O	= Save the file and then press Enter
CTL+X	= Exit "nano"
CTL+K	= Delete line
CTL+U	= Undelete line
CTL+W	= Search for %%string%%
CTL+\	= Search for %%string%% and replace with $$string$$
CTL+C	= Show line numbers

More info = http://en.wikipedia.org/wiki/Nano_(text_editor)

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Step 8.3 Increase number of open files available

Open the following file as follows:

sudo nano /etc/security/limits.conf

Add the following to the bottom of the file:

*            hard       nofile          65536
*            soft       nofile          65536

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NANO Editor Help

CTL+O	= Save the file and then press Enter
CTL+X	= Exit "nano"
CTL+K	= Delete line
CTL+U	= Undelete line
CTL+W	= Search for %%string%%
CTL+\	= Search for %%string%% and replace with $$string$$
CTL+C	= Show line numbers

More info = http://en.wikipedia.org/wiki/Nano_(text_editor)

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Make sure to check the files open parameter with the next computer reboot by typing the following as the root user:

ulimit -n

References

• http://wiki.apache.org/tomcat/FAQ/Memory
• http://en.wikipedia.org/wiki/Java_performance#Memory_usage
• http://javaperformancetuning.com
• http://wiki.lib.sun.ac.za/index.php/SUNScholar/Optimisations
• https://wiki.duraspace.org/display/DSDOC3x/Performance+Tuning+DSpace

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