How to solve Wildfly 10 Memory Leak Issue?

You have to increase your heap memory. For this

Edit bin/standalone.conf configuration file, look for the first occurrence of JAVA_OPTS.

Then change the -Xmx option as you need.

If you use Java 8, then

Change:

JAVA_OPTS=”-Xms64m -Xmx512m -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=256m -Djava.net.preferIPv4Stack=true”

To:

JAVA_OPTS=”-Xms64m -Xmx2G -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=2G -Djava.net.preferIPv4Stack=true”

Resource Link:

WildFly 10 — java.lang.OutOfMemoryError: Metadata space

UPDATE: Classes not unloaded after undeployment

Martin kouba stated below

1. undeploy does not necessarily mean class unloading - it depends on JVM settings (-XX:MaxMetaspaceSize and friends for Java8)
2. I've verified that after 50 deploy/undeploy cycles of the attached reproducer (and using -XX:MaxMetaspaceSize=128m):

for WildFly 10.0.0.Final "java.lang.OutOfMemoryError: Metaspace" occurs

for WildFly 10.1.0-SNAPSHOT (fix for WFLY-6347 merged) no OOM error occurs (metaspace is garbage collected)

After examining the heap dump I've identified the org.jboss.el.cache.BeanPropertiesCache as the root cause. In this case, it keeps a hard reference to the person.joey.test.TestClientBean class, thus effectively blocking the relevant ModuleClassLoader from GC.

Enum values are treated similarly to static constants - i.e. it's not garbage collected unless the class loader of the owner class is.

That's why person.joey.test.RequestType values remain in memory. OmniFaces only amplifies the impact - as mentioned above, it holds a reference to a BeanManager.

Resource Link: https://stackoverflow.com/a/38875640/2293534