1.参考:

​http://hi.baidu.com/like_dark/blog/item/19c1948b3292b0799f2fb468.html​

​http://anyeeye.iteye.com/blog/444624​

​Tomcat6性能调优 出现java.lang.OutOfMemoryError: PermGen space​

​http://www.mkyong.com/tomcat/tomcat-javalangoutofmemoryerror-permgen-space/​

2.报错:


Exception in thread "DispatcherThread" java.lang.OutOfMemoryError: PermGen spaceException in thread "ContainerBackgroundProcessor[StandardEngine[Catalina]]" java.lang.OutOfMemoryError: PermGen space Exception in thread "State Saver" java.lang.OutOfMemoryError: PermGen space Exception in thread "AWT-Windows" java.lang.OutOfMemoryError: OutOfMemoryError

3.原因:

PermGen space的全称是Permanent Generation space,是指内存的永久保存区域,

这块内存主要是被JVM存放Class和Meta信息的,Class在被Loader时就会被放到PermGen space中,

它和存放类实例(Instance)的Heap区域不同,GC(Garbage Collection)不会在主程序运行期对

PermGen space进行清理,所以如果你的应用中有很多CLASS的话,就很可能出现PermGen space错误,

这种错误常见在web服务器对JSP进行pre compile的时候。如果你的WEB APP下都用了大量的第三方jar, 其大小

超过了jvm默认的大小(4M)那么就会产生此错误信息了。

4.解决方法1: 

手动设置MaxPermSize大小,如果是linux系统,修改TOMCAT_HOME/bin/catalina.sh,如果是windows系统,修改TOMCAT_HOME/bin/catalina.bat,

在“echo "Using CATALINA_BASE: $CATALINA_BASE"”上面加入以下行:

JAVA_OPTS="-server -XX:PermSize=64M -XX:MaxPermSize=128m

建议:将相同的第三方jar文件移置到tomcat/shared/lib目录下,这样可以达到减少jar 文档重复占用内存的目的。

5.解决方法2

修改eclipse.ini文件,修改如下:


-vmargs-Dosgi.requiredJavaVersion=1.5 -Xms128m -Xmx512m -XX:PermSize=64M -XX:MaxPermSize=128M 如果还报错,可以考虑如下修改



-vmargs-Dosgi.requiredJavaVersion=1.5 -Xms512m -Xmx1024m -XX:PermSize=256M -XX:MaxPermSize=512M


报错:


2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc严重: The web application [/Application] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. 2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads 严重: The web application [/Application] appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak. 2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads 严重: The web application [/Application] appears to have started a thread named [AWT-Windows] but has failed to stop it. This is very likely to create a memory leak. 2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads 严重: The web application [/Application] appears to have started a thread named [Thread-14] but has failed to stop it. This is very likely to create a memory leak. 2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap 严重: The web application [/Application] created a ThreadLocal with key of type [net.sf.json.AbstractJSON$1] (value [net.sf.json.AbstractJSON$1@3661eeb]) and a value of type [java.util.HashSet] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak. 2011-11-21 21:10:50 org.apache.catalina.core.ApplicationContext log 信息: Initializing Spring FrameworkServlet 'Dispatcher'



修改catalina.bat

添加

JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms1536m -Xmx1536m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+DisableExplicitGC"

样例

# JSSE_HOME (Optional) May point at your Java Secure Sockets Extension# (JSSE) installation, whose JAR files will be added to the # system class path used to start Tomcat. # # CATALINA_PID (Optional) Path of the file which should contains the pid # of catalina startup java process, when start (fork) is used # # $Id: catalina.sh 609438 2008-01-06 22:14:28Z markt $ # ----------------------------------------------------------------------------- JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms1536m -Xmx1536m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+DisableExplicitGC" # OS specific support. $var _must_ be set to either true or false. cygwin=false os400=false darwin=false case "`uname`" in CYGWIN*) cygwin=true;; OS400*) os400=true;; Darwin*) darwin=true;; esac # resolve links - $0 may be a softlink PRG="$0"


具体参数根据自己机器情况而定

JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms512m -Xmx512m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m -XX:MaxPermSize=256m -XX:+DisableExplicitGC"