The optimal file cache size is dependent on whether you are running a 32-bit or a 64-bit server. The available address space for a 32–bit server is limited to 4GB. The max-entries for file cache is based on the amount of Java heap, the number of threads (as specified by thread-pool/max-threads), and the connection queue size. It is recommended to cache small, frequently accessed static files in the file cache and use perfdump to ensure that the file cache hit ratio is close to 100%. To achieve this, you may increase file cache size and fine tune the max-entries for optimal performance. In a 64-bit server, due to the increased availability of address space, you can cache more static content in the file cache.
You can set the maximum number of cached entries in the Admin Console in the Maximum Entries field on the configuration's Performance tab ⇒ Cache tab, under File Cache. In the command-line interface, use wadm set-file-cache-prop and set the max-entries property. The default is 1024. The range of values is 1-1048576.