Open the Code Extensions view (Administration 
System Code Extensions).
Select Actions Build Extensions Cache.
If you want to clear the cache on the current node,
Set to true at the global level to enable caching for code extensions and extension triggers. This improves performance efficiency by calling extensions from the cache instead of querying the database for each request. Updates to the code extension are propagated to all the cluster nodes.
When this is false (default), N4 does not create an extensions cache and always queries the database for the code extension or the extension trigger.
To enable caching for code extensions:
Update FRMCARINA039 (ENABLE_EXTENSION_CACHING) to true at the global level.
Open the Code Extensions view (Administration System Code Extensions).
Select Actions Build Extensions Cache.
If you want to clear the cache on the current node,
Select Actions Clear Extensions Cache.
Choose Yes. This will clear the cache on only the current node.
Even though you enable extension caching, it is necessary to manually trigger build/rebuild extension cache using the action Build Extensions Cache in the Code Extensions view (on page 1) to create the cache. Enabling the cache extension setting alone will not build the cache.