How Can I Determine The Java Heap Size And Memory Usage In Linux For Java?

You can use the following methods to find the Java heap size and memory used in Linux:

  1. Using the ‘jstat’ command:

    • Open the terminal and run the command: jstat -gc <pid>
    • Replace <pid> with the process ID of your Java application.
    • This command will display several columns, including ‘S0C’, ‘S1C’, ‘EC’, ‘OC’, ‘MC’, and ‘CCSC’.
    • ‘OC’ represents the old generation heap size, and ‘MC’ represents the metaspace size.
    • ‘S0C’ and ‘S1C’ represent the survivor spaces, while ‘EC’ represents Eden space.
  2. Using the ‘jcmd’ command:

    • Open the terminal and run the command: jcmd <pid> VM.flags
    • Replace <pid> with the process ID of your Java application.
    • Look for the output line starting with -Xmx, which indicates the maximum heap size.
    • Another line starting with -XX:MaxMetaspaceSize indicates the maximum metaspace size.
  3. Using the ‘top’ command:

    • Open the terminal and run the command: top -p <pid>
    • Replace <pid> with the process ID of your Java application.
    • Press ‘Shift + F’ and then ‘n’ to sort by memory usage.
    • Look for the Java process in the list and check the ‘VIRT’ and ‘RES’ columns.
    • ‘VIRT’ represents the virtual memory size, and ‘RES’ represents the resident memory size.

Note: The above-mentioned methods assume that you have the necessary tools (jstat, jcmd, and top) installed on your Linux system.

About the Author Rex

I'm a passionate tech blogger with an insatiable love for programming! From my early days tinkering with code, I've delved into web dev, mobile apps, and AI. Sharing insights and tutorials with the world is my joy, connecting me to a global community of like-minded tech enthusiasts. Python holds a special place in my heart, but I embrace all challenges. Constantly learning, I attend tech conferences, contribute to open-source projects, and engage in code review sessions. My ultimate goal is to inspire the next generation of developers and contribute positively to the ever-evolving tech landscape. Let's code together!