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Benefits of Setting Initial and Maximum Memory Size to the Same Value

When we launch applications, we specify the initial memory size and maximum memory size. For the applications that run on JVM (Java Virtual Machine), initial and maximum memory size is specified through "-Xms" and "-Xmx" arguments. If Java applications are running on containers, it’s specified through "-XX: InitialRAMPercentage" and "-XX: MaxRAMPercentage" arguments. Most enterprises set the initial memory size to a lower value than the maximum memory size. As opposed to this commonly accepted practice, setting the initial memory size the same as the maximum memory size has certain "cool" advantages. Let’s discuss them in this post.

1. Availability

Suppose you are launching your application with the initial heap size to be 2GB and the maximum heap size to be 24GB. This means when the application starts, the operating system will allocate 2GB of memory to your application. From that point, as the application starts to process new requests, additional memory will be allocated until a maximum of 24GB is reached. 

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Large or Small Heap Size? [Video]

Do you want to run your application with a large heap size or a small heap size? What is the right strategy? Which strategy is more expensive? Which is more performant? Watch this video to know more!

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Chaos Engineering: Thread Leak

In the series of chaos engineering articles, we have been learning to simulate various performance problems. In this post, let’s discuss how to simulate thread leaks. ‘java.lang.OutOfMemoryError: unable to create new native thread’ will be thrown when more threads are created than the memory capacity of the device. When this error is thrown, it will disrupt the application’s availability.

Sample Program

Here is a sample program from the open source BuggyApp application, which keeps creating an infinite number of threads.

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Shallow Heap vs. Retained Heap [Video]

Eclipse MAT is a powerful tool to analyze heap dumps. It comes in handy when debugging OutOfMemoryError. Eclipse MAT reports two types of object size: 1) Shallow Heap 2) Retained Heap. This video explains the difference between them and how they are calculated. Watch this video to learn more!

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Best Practices: Java Memory Arguments for Containers

When running your Java application in physical servers, you would have been using ‘-Xmx’ JVM argument to specify the Java heap size. If you are porting your application to Containers, you might be wondering how to configure Java heap size in the container’s world? Are there any best practices? In this article, we will discuss the possible JVM arguments that can be used to specify the Java heap size and the best option to choose. 

There are 3 different options to specify the maximum Java heap size in containers. They are:

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Difference Between InitialRAMPercentage, MinRAMPercentage, MaxRAMPercentage

This article attempts to clarify the difference between InitialRAMPercentage, MinRAMPercentage, MaxRAMPercentage JVM arguments. These arguments have been introduced since Java 8 update 191. They are used to configure your Java application’s heap size when you are running it in the Physical server or in the container. In this article, let’s review their differences.

InitialRAMPercentage

‘-XX:InitialRAMPercentage’ is used to compute the initial heap size of your java application. Say suppose you are configuring -XX:InitialRAMPercentage=25 and overall physical memory (or container memory) is 1GB then your java application’s heap size will be ~250MB (i.e., 25% of 1GB).