How to Solve the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded

1. the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded Error
2. Solve the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded Error

This tutorial demonstrates the Java.lang.outofmemoryerror: GC overhead limit exceeded error in Java.

the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded Error

Unlike other programming languages, Java runtime uses a garbage collector GC process for Garbage collection. In Java, the garbage collector will clear the memory for them whenever a particular part of memory is not used.

The error Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded occurs when our code or application is exhausted all the memory, and GC cannot clean the memory anymore.

The error Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded signals that the JVM has taken too long to perform the garbage collection. JVM will throw this error when it takes 98% of the time to do the garbage collection, and only the other 2% of the heap can recover.

Here is an example that throws the same error:

package delftstack;

import java.util.*;
public class Example {
  public static void main(String args[]) throws Exception {
    Map DemoMap = System.getProperties();
    Random DemoRandom = new Random();
    while (true) {
      DemoMap.put(DemoRandom.nextInt(), "value");
    }
  }
}

The code above will continuously put the random value in the map until garbage collection reaches 98%, and it will throw the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded. The heap memory is used in the maps.

See output:

Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "main"

Even if we run this code using a parallel garbage collector, it will still throw the same error. See the example through CMD:

java -Xmx100m -XX:+UseParallelGC Example.java

It will still throw the same error. See output:

C:\Users\Sheeraz>java -Xmx100m -XX:+UseParallelGC Example1.java
Note: Example1.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Exception in thread "main" java.lang.OutOfMemoryError: GC overhead limit exceeded
        at java.base/java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1047)
        at java.base/java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:1006)
        at java.base/java.util.Properties.put(Properties.java:1301)
        at delftstack.Example.main(Example1.java:9)

Solve the Java.Lang.OutOfMemoryError: GC Overhead Limit Exceeded Error

The solution to this error is to prevent memory leaks. Make sure the points below are followed so you can prevent memory leaks:

1. Identify the places where memory allocation for the heap is done.
2. It is the best practice to avoid creating a large amount of weakly referenced or temporary objects because mostly, they are the reason for memory leakage.
3. Identify the object which occupies a large space on the heap.