Limited and Unlimited Cache Size

Performance of the system is best when all the data is in cache, which can have unlimited or limited size.

If the amount of data exceeds the amount of memory available in the cache machines, you must limit the cache size and use a backing store to store additional data. Some applications use the backing store as the main storage and retrieve objects from the backing store as needed.

Note: Use of limited cache is supported only with the use of a backing store, which retains entries in excess of the limit. Without use of a backing store the following data inconsistencies could result:
  • Entries for an object in the object table (an internally used cache) and in the object cache itself could expire independently of each other.
  • Domain object settings for limited cache apply at the object level. Related concepts could have different settings. For example, a container concept could have a limited cache setting and its container concept an unlimited cache setting. Each could be evicted at different times.
Note: Only use an unlimited cache if you deploy enough cache agents to handle the data. Otherwise out of memory errors may occur.

For backing store configuration, see JDBC Backing Store Setup in TIBCO BusinessEvents Developer’s Guide.