You can use "-Xms128m -Xmx256m" which means the heap will start at 128m and
grow to 256m, but you are better off testing your app first (use verboseGC)
to check the memory usage and then setting both parameters to the same no.
(i.e.) "-Xms256m -Xmx256m" or to a value suitable to your app usage and you
will avoid a delay when the copy occurs after the intial setting.
I would also suggest that you need to tune up your process, file, inode
limits at the OS front. If you are going to run 7 instances of Tomcat on a
512mb machine, you will run out of these fast.
If you are running 2.2.x kernel series, it is a wee bit more complicated.
2.4.x series, you are better off.
Plenty of stuff on the web on this, but a good point to start is
http://people.redhat.com/alikins/system_tuning.html
-- Aravind
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Craig R. McClanahan
Sent: Saturday, 25 August 2001 11:42
To: Tomcat Users List; Max Hugen
Subject: Re: OutOfMemory - Set Java Heap Size?
The "java" command line option you want is actually "-Xmx256m" to set the
maximum heap size. To set this, you can establish an environment variable
named TOMCAT_OPTS (Tomcat 3.x) or CATALINA_OPTS (Tomcat 4.x) that contains
the command line options to be sent to the JVM. For example:
export TOMCAT_OPTS="-Xmx256m"
$TOMCAT_HOME/bin/tomcat.sh start
Craig McClanahan
On Sat, 25 Aug 2001, Max Hugen wrote:
> Date: Sat, 25 Aug 2001 13:00:41 +1000
> From: Max Hugen <[EMAIL PROTECTED]>
> Reply-To: [EMAIL PROTECTED], Max Hugen
<[EMAIL PROTECTED]>
> To: Tomcat Users List <[EMAIL PROTECTED]>
> Subject: OutOfMemory - Set Java Heap Size?
>
> I run Linux/Apache/Tomcat plus Oracle on a server with 512Mb of memory. I
> have successfully implemented a couple of Internet applications using JSP,
> Servlets (plus Oracle) etc.
>
> For each application (and client) I start a new Tomcat session, using a
> custom server.xml for each one. All was ok, until I tried increasing
Tomcat
> sessions from 6 to 7, then I received the java.lang.OutOfMemoryError when
> starting the Tomcat sessions.
>
> I've read through many of the posts on this subject, some of which suggest
> to increase the "heap" size. Unfortunately, I'm a newbie to Java (and
Linux
> and JSP and Oracle <g>) so I don't know how to either check this heap
size,
> nor how to permanently set it to a value via a script using a switch
> like -Xms256m.
>
> The script I use to start Tomcat follows, plus the console output. Could
> anyone advise how to set the heap please?
>
>
> Many thanks,
>
> Max Hugen [EMAIL PROTECTED]
> Hugen Enterprises Pty Ltd, Sydney, Australia
> www.hugen.com.au
> Internet Application Developers
>
> >>>>>>>>>Script Start>>>>>>>>
> echo "~~~~~~~~Tomcat Startup ~~~~~~~~~~~~~"
> echo "Start an instance of Tomcat for hugen"
> /usr/local/tomcat/bin/startup.sh -f /usr/local/tomcat/conf/server_he.xml
> echo "Start an instance of Tomcat for yass3i"
> /usr/local/tomcat/bin/startup.sh -f
/usr/local/tomcat/conf/server_yass3i.xml
> echo "Start an instance of Tomcat for isp"
> /usr/local/tomcat/bin/startup.sh -f /usr/local/tomcat/conf/server_isp.xml
> echo "Start an instance of Tomcat for im2000i"
> /usr/local/tomcat/bin/startup.sh -f
> /usr/local/tomcat/conf/server_im2000i.xml
> echo "Start an instance of Tomcat for secure"
> /usr/local/tomcat/bin/startup.sh -f
/usr/local/tomcat/conf/server_secure.xml
> echo "Start an instance of Tomcat for aedo"
> /usr/local/tomcat/bin/startup.sh -f /usr/local/tomcat/conf/server_aedo.xml
> echo "Start an instance of Tomcat for ncap"
> /usr/local/tomcat/bin/startup.sh -f /usr/local/tomcat/conf/server_ncap.xml
> # Give Tomcat time to start before restarting Apache.
> echo "Waiting 45 secs..."
> sleep 45
> # Restart Apache to register Tomcat properly.
> echo "Restart Apache"
> /etc/rc.d/init.d/httpd stop
> /etc/rc.d/init.d/httpd start
> sleep 2
> echo "Ok, we should be in business!"
> >>>>>>>>>Script End>>>>>>>>
>
> >>>>>>>>>Console Output Start>>>>>>>>
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
> Starting tomcat. Check logs/tomcat.log for error messages
>
> Restart Apache
>
> Exception in thread "main" java.lang.OutOfMemoryError: unable to create
new
> native thread
> at java.lang.Thread.start(Native Method)
> at
>
org.apache.tomcat.util.ThreadPool$ControlRunnable.<init>(ThreadPool.java:465
> )
> at
> org.apache.tomcat.util.ThreadPool.openThreads(ThreadPool.java:360)
> at org.apache.tomcat.util.ThreadPool.start(ThreadPool.java:148)
> at
>
org.apache.tomcat.service.PoolTcpEndpoint.startEndpoint(PoolTcpEndpoint.java
> :245)
> at
>
org.apache.tomcat.service.PoolTcpConnector.start(PoolTcpConnector.java:188)
> at
> org.apache.tomcat.core.ContextManager.start(ContextManager.java:527)
> at org.apache.tomcat.startup.Tomcat.execute(Tomcat.java:202)
> at org.apache.tomcat.startup.Tomcat.main(Tomcat.java:235)
>
> Exception in thread "main" java.lang.OutOfMemoryError: unable to create
new
> native thread
> at java.lang.Thread.start(Native Method)
> at
>
org.apache.tomcat.util.ThreadPool$MonitorRunnable.<init>(ThreadPool.java:382
> )
> at org.apache.tomcat.util.ThreadPool.start(ThreadPool.java:149)
> at
>
org.apache.tomcat.service.PoolTcpEndpoint.startEndpoint(PoolTcpEndpoint.java
> :245)
> at
>
org.apache.tomcat.service.PoolTcpConnector.start(PoolTcpConnector.java:188)
> at
> org.apache.tomcat.core.ContextManager.start(ContextManager.java:527)
> at org.apache.tomcat.startup.Tomcat.execute(Tomcat.java:202)
> at org.apache.tomcat.startup.Tomcat.main(Tomcat.java:235)
>
> Shutting down Web Service: httpd
>
> /etc/rc.d/init.d/httpd: fork: Resource temporarily unavailable
> Web Service: /usr/sbin/httpd
>
> >>>>>>>>>Console Output End>>>>>>>>
>
>
