Why JSF throw OutOfMemoryError in Tomcat 7?

Question

I have a fresh and clean Tomcat7 ready in my Windows machine, when I remove the JSF jars (jsf-api-2.0.1.jar and jsp-impl-2.0.1.jar) from WEB-INF/lib, I hit this error:

Caused by: java.lang.ClassNotFoundException: javax.faces.FacesException
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    ... 10 more

When I put the 2 jars in WEB-INF/lib, I hit error:

java.lang.OutOfMemoryError: PermGen space
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2818)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1148)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1643)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at org.apache.catalina.startup.ContextConfig.checkHandlesTypes(ContextConfig.java:1956)
    at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:1919)
    at org.apache.catalina.startup.ContextConfig.processAnnotationsJar(ContextConfig.java:1806)
    at org.apache.catalina.startup.ContextConfig.processAnnotationsUrl(ContextConfig.java:1765)
    at org.apache.catalina.startup.ContextConfig.processAnnotations(ContextConfig.java:1751)
    at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1255)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:882)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:317)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:89)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5081)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1033)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:774)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1033)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:291)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:727)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:620)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Any clue on running JSF in Tomcat 7?

Please read [performance-tuning-jvm-running-tomcat](http://www.tomcatexpert.com/blog/2011/11/22/performance-tuning-jvm-running-tomcat) and other articles [here](http://www.tomcatexpert.com/tags/tomcat-performance) — Ravi Kadaboina, Nov 07 '12 at 05:02

score 2 · Accepted Answer · edited May 23 '17 at 12:04

You haven't indicated if the error occurs instantly on deploy or after a while. If it occurs after a while, i.e. during your application run, your code will be to blame. Look at this excellent article that will help you use JDK 6 track down the source of the error.

A PermGen error is indicative of classloading issues pertaining to your application container.The Permanent Generation (PermGen for short) is the area where the JVM stores objects such as classes and string literals. Normally, the garbage collector is not supposed to operate frequently here. Classes loaded by the app server should be automatically cleaned up once the classloader for the web application (there is one per deployed webapp) is no longer being used. Tomcat has given me problems in this area in the past (especially when used within Netbeans). It seems to not be able to clean up after itself effectively after repeated redeploys. There are a handful of things you could do apart from increasing the size of the permgen space

1) You could move the common jars for the web applications running in that tomcat instance into the TOMCAT_HOME/lib. This way, you can expect your class libraries to not be loaded multiple times per requiring web application as is the default behaviour for tomcat(see this). Use this option with care however; if you eventually deploy a web application containing newer versions of the jar, you might run into NoClassDefFound errors.

2)You can try this -XX:MaxPermGen instead of (or in addition to) the -XX:MaxPermSize that mkyong suggested in his article.

Also take a look at this question and it's answers for further steps

I am running Tomcat in Eclipse IDE, may I know how could I set the 2 variables you mention in entry 2? — huahsin68, Nov 07 '12 at 13:23
See this link on how to do that http://viralpatel.net/blogs/setting-tomcat-heap-size-jvm-heap-eclipse/ — Ravi Kadaboina, Nov 07 '12 at 17:48
@Ravi, clear tutorial, but what it addresses is the setting for a heap-related error, not for the PermGen — kolossus, Nov 07 '12 at 20:08
@huahsin68, see [this answer](http://stackoverflow.com/a/7387985/1530938) for a screenshot and add the `-XX:MaxPermGen=128M`, where `128M` corresponds to the amount of memory you're going to dedicate. Don't over allocate though, I'd recommend 512M — kolossus, Nov 07 '12 at 20:13

Why JSF throw OutOfMemoryError in Tomcat 7?

1 Answers1