Configure NRE Memory Pools window

This window provides a mechanism to configure NRE (Node Runtime Environment) memory.

A fixed memory footprint serves all the memory pools. Adjusting one pool affects at least one other pool.

CAUTION: Configuring a controller with insufficient memory allocations could prevent the station from starting or could cause the station to fail and restart.

Figure 1. Configure NRE Memory Pools window

To access Configure NRE Memory Pools window, open the Platform Administration view and click Configure NRE Memory. The descriptions shown in the window include recommended allocation sizes. If you adjust the space allocation for any of the memories described above, you must reboot the controller for the new configuration to become effective.

Table 1. NRE memory default sizes in MB
Type of memory	MB	Description
System Reserve Size	0	Allocates additional free operating system space. By default, this is set to 0MB. The reason you might reserve additional free operating system space is if additional system RAM is needed when a new thread is spawned by the station or niagarad (daemon) for native stack and overhead.
Heap Space Size	384	Configures where the station runs. As your program grows it requires more heap memory.
Meta Space Size	128	Holds all of the Java classes that are loaded from the modules. As you install more drivers, this increases the number of .jar files holding the classes.
Code Cache Size	32	Holds code that has already been compiled. Java functions with a JIT (Just-In-Time) compiler. As Java executes classes, it compiles code on the fly. Saving code that it has already compiled to the Code Cache eliminates the need to compile it again. Code that is used most often is cached. However, since there is a limited amount of memory available to cache code, it continues using the compiler as the station runs. If you adjust the memory allocation to allow a significant amount of space for code caching the station runs faster, but the risk is in taking away too much memory from the other memory spaces resulting in the station being unable to run at all.
Free Memory	~352