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Adjusting system memory allocation

You can adjust system memory allocation to improve overall performance by setting the /proc/sys/vm/max_map_count kernel tuning parameter. Doing this can prevent problems such as the slowing down of batch execution and a continuous increase of memory used by the JVM.

About this task

A good setting to use is four times the number of megabytes of system memory. For example, if you’re running on a system with 128 gigabytes of memory, then calculate (128*1024=131072 megabytes) times 4, which is 524288.

Steps

  1. Sign on as root user.

  2. Add the line vm.max_map_count = <megabytes> to the file /etc/sysctl.conf. For example:

    vm.max_map_count = 524288

  3. Restart the system to apply the change.

  4. Optional: If you need to tune performance further after setting the max_map_count parameter, do the following:

    1. Clone the existing performance profile.

    2. Run the tuned command.

    3. Add the line vm.max_map_count = <megabytes> to the file /usr/lib/tuned/profile-name/tuned.conf.

    4. To select the updated profile, run tuned-adm profile customized_profile.

    5. Restart the system to apply the changes.