Java memory usage

Typically you do not have to tune the Java™ VM's use of memory. However, in certain conditions, consider using runtime options to change the default behavior.

If you use SSL-offloading at Diffusion™

If your clients make secure connections to the Diffusion server and these connections are SSL offloaded at the Diffusion server , ensure that you tune the following runtime options:

-Xmx: Sets the maximum heap size.
-XX:MaxDirectMemorySize: Sets the maximum total size (in bytes) of direct-buffer allocations. By default, the JVM chooses the size for direct-buffer allocations automatically.
Diffusion uses direct memory to offload SSL connections.

Ensure that the combined total of these two values does not exceed 80% of the RAM available on your system.

When terminating SSL connections at Diffusion , Java can consume significant CPU resource in encryption library code. Run the Diffusion server on Java 8 update 121 or later to take advantage of flags which enable optimizations which significantly reduce CPU utilization when the Diffusion server receives a sustained and high client session connection rate.