vRealize Hyperic server uses Ehcache for in-memory caching. Effective cache management is necessary for server stability and performance.

Caching policies that define the cache size (maximum number of objects to cache) for each type are defined in server-n.n.n-EE\hq-engine\hq-server\webapps\ROOT\WEB-INF\classes\ehcache.xml. The cache size for a type depends on the on how often it likely to be is updated.

Given a fixed amount of memory, cache sizing in vRealize Hyperic attempts to allocate cache according to these guidelines:

  • Relatively static types - Caches for types that are not frequently updated. For example, resource, platform, server, and measurement resized to keep objects in memory for the lifetime of the server. An very low miss rate preferable.

    The default cache sizes (the maximum number elements in cache) configured in ehcache.xml for inventory types are:

    • Platforms - 2,000

    • Servers ---- 50,000

    • Services - 100,000

      This sizing should be adequate for medium to large deployments.

Dynamic types - Caches for types that are frequently updated - for example, Alert and Galert - and therefore get stale sooner, are configured such that objects age more quickly. A high hit/miss ratio is optimal for dynamic types, in larger environments, in the order of 2:1 or 4:1.