1. A method of optimizing just-in-time (‘JIT’) compiling for a Java application executing on a compute node, the compute node having installed upon it a Java Virtual Machine (‘JVM’) capable of supporting the Java application, the method comprising: identifying, by an application manager, a particular portion of the Java application; assigning, by the application manager, a JIT level to the particular portion of the Java application; and jitting, by the JVM installed on the compute node, the particular portion of the Java application in dependence upon the JIT level assigned to that particular portion of the Java application.