You can modify the size of a vRealize Hyperic cache by editing an element in the ehcache.xml file. Generally, only cache sizes need to be changed.
The ehcache.xml file can be found under server-n.n.n-EE\hq-engine\hq-server\webapps\ROOT\WEB-INF\classes\.
Each cache is defined with an entry like
<cache name="DerivedMeasurement.findByTemplateForInstance" maxElementsInMemory="10000" eternal="true" timeToIdleSeconds="0" timeToLiveSeconds="0" memoryStoreEvictionPolicy="LRU"/>
You might need to iterate the cache size until you find the optimal setting.
Caches that you Cannot Change
There are two caches that you cannot configure:
org.hibernate.cache.UpdateTimestampsCache, which is managed by Hibernate
AvailabilityCache, which is managed by the vRealize Hyperic server