Getting below error when running the war file in tomcat7 (Ubuntu):
Exception in thread "http-bio-8080-AsyncTimeout" java.lang.OutOfMemoryError: Java heap space
at java.util.concurrent.ConcurrentLinkedQueue.iterator(ConcurrentLinkedQueue.java:667)
at org.apache.tomcat.util.net.JIoEndpoint$AsyncTimeout.run(JIoEndpoint.java:156)
at java.lang.Thread.run(Thread.java:745)
I am getting above exception when I have put my app.war file in webapps path.
Increase the heap size is a must. You could create or edit the $CATALINA_HOME/bin/setenv.sh, add the line:
JAVA_OPTS="-Xms1024m -Xmx2048m"
And then restart tomcat. I think it is better to unpack the war file and copy it to $CATALINA_HOME/webapps, and furthermore, using hot-deploy in production is not a good idea.
In my case it happens if Im deploying my application without restarting tomcat. I think GC (garbage-collector) has some problems to free the allocated memory.
My workaround is:
this is common in the Java world and actually still might affect JRuby ... although hot-deploys are much smoother these days if you're on latest >= 1.7.15 and using jruby-openssl >= 0.9.5. but there still might be gems/libraries that will impose issues reloading and thus will leak memory (one such library is require 'timeout') so you'll need to review the heap dump for leak candidates. also Tomcat usually prints useful hints related to "potential" leak candidates during un/re-deploys.
now, there are things to make sure. if you're on Java 6 you need to use the concurrent (mark-and-sweep) GC as others do not swap the heap space and it's not the default, even so you will need to increase the heap size if you're planning hot-reloads since it needs to be able to hold twice your application's (Java) classes.
