Managing Java Memory Allocation for Your Web Application

Better performance and scalability of an application do not always depend on the amount of memory allocated. There are often occasions where allocating more memory has resulted in an adverse situation. This blog explores the adverse impact of performance degradation and explains how to create a balance while allocating memory to Java applications.

Enterprise applications sizing background

For this exercise, we will refer to our in-house IT operations product, which is being used for the end-to-end operations management of our own IT business unit as well as multiple enterprise-level customers. It’s important to understand the volumetrics that the solution will be monitoring. This will help us reverse engineer and map the numbers to our BMC-recommended system requirements, which are documented as part of the sizing and scalability guidelines. Once this mapping is established, it becomes less complicated to size the IT operations stack.

You can find additional information on presentation server sizing and scalability here and information on infrastructure management server sizing and scalability here.

Does the process need extra memory?

Once deployed, we should make it a practice to monitor the health of the stack. This will help us to understand whether any modifications are needed to meet changing business requirements. In addition, any performance degradation in the stack will proactively trigger an alarm, making it easier for us to remediate before end users are impacted.

Different layers of monitoring include:

1. Monitoring the logs from the application
2. Operating system monitoring
3. Java Virtual Machine (JVM) monitoring

The Java Development Kit (JDK) comes bundled with VisualVM, which helps us to get a holistic view of the running JVMs, including overall memory consumption and the respective threads associated with the same.

The above analysis will help us investigate further and may result in enhancing or reducing current resources allocated to the stack. We would need to map the findings according to the sizing documents referenced above and look for discrepancies, based on the specific process or thread that we are analyzing.