在看下文之前,首先要確認意見事情,就是你是如何啓動tomcat的,我們在平時的開發環境當中,都是通過startup.bat方式啓動tomcat的,那麼你按照下面的方式,去修改/bin/catalina.bat是沒有問題的。但是如果你是生產環境下,我們一般都希望使用windows服務方式去啓動tomcat,此時之前修改的配置文件是沒有用的。因爲windows服務啓動tomcat不再去加載catalina.bat當中的參數了,而是去加載註冊表中的參數,所以我們需要修改註冊表。
HKEY_LOCAL_MACHINE/SOFTWARE/Apache Software Foundation/Procrun 2.0/Tomcat_APPNAME/Parameters/Java,修改JvmMs和JvmMx的值,當前我都將其設定爲1024,也就是1個G的容量。具體性能再後面繼續觀察。 之前還真不知道windows服務啓動和startup.bat啓動的區別。 windows服務器啓動是在註冊表中加載參數,startup.bat啓動是在catalina.bat加載參數。
1.參考:
http://blog.csdn.net/fox009/article/details/5633007
http://hi.baidu.com/like_dark/blog/item/19c1948b3292b0799f2fb468.html
http://anyeeye.iteye.com/blog/444624
Tomcat6性能調優 出現java.lang.OutOfMemoryError: PermGen space
2.報錯:
Exception in thread "DispatcherThread" java.lang.OutOfMemoryError: PermGen space Exception 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的全稱是Permanent Generation space,是指內存的永久保存區域,這塊內存主要是被JVM存放Class和Meta信息的,Class在被Loader時就會被放到PermGen space中,它和存放類實例(Instance)的Heap區域不同,GC(Garbage Collection)不會在主程序運行期對PermGen space進行清理,所以如果你的應用中有很多CLASS的話,就很可能出現PermGen space錯誤,這種錯誤常見在web服務器對JSP進行pre compile的時候。如果你的WEB APP下都用了大量的第三方jar, 其大小超過了jvm默認的大小(4M)那麼就會產生此錯誤信息了。4.解決方法1:
手動設置MaxPermSize大小,如果是linux系統,修改TOMCAT_HOME/bin/catalina.sh,如果是windows系統,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
建議:將相同的第三方jar文件移置到tomcat/shared/lib目錄下,這樣可以達到減少jar 文檔重複佔用內存的目的。
5.解決方法2
修改eclipse.ini文件,修改如下:
-vmargs -Dosgi.requiredJavaVersion=1.5 -Xms128m -Xmx512m -XX:PermSize=64M -XX:MaxPermSize=128M如果報錯
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc 嚴重: 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 嚴重: 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 嚴重: 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 嚴重: 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 嚴重: 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'則
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"
6.解決方法3
如果是Eclipse與tomcat集成則在MyEclipse/Servers/Tomcat/Tomcat x.x /jdk 中Opional Java VM arguments:-Xms1024M -Xmx2048M -XX:PermSize=1024M -XX:MaxNewSize=512M -XX:MaxPermSize=1024M