Configuring In-Memory Caches

In-memory caching reduces the number of trips the application makes to its database by holding often-requested data in memory. When you configure cache servers, you give each server the list of all cache server machines. For example, you might edit the list of cache server machines when you're adding or removing servers.

For information on adding and removing cache servers, see Managing Cache Servers. For information on installing cache servers, see Setting Up a Cache Server.

The Caches page in the Admin Console lists the application's caches and provides information on how well they're being used. This information is for use in troubleshooting if you need to call Jive support.

Fastpath: Admin Console: System > Settings > Caches

Note: In versions prior to 4.5, you might have needed to adjust cache sizes in order to improve performance. As of version 4.5, cache sizes are adjusted by the application based on JVM heap usage. Also, the short-terms query cache setting has been removed because it is no longer needed in the caching system.

Registering Cache Servers

You register cache server machines by entering their IP or domain name in the Cache Servers box of the Caches Admin Console page. If you're running multiple cache server machines, they must all be listed in the Cache Servers box. The same list must be configured on every node in the cluster.

CAUTION:

If you're setting up more than one cache server machine, you must use three or more. The CACHE_ADDRESSES value should list them in a comma-separated list. Using only two cache servers is not supported and can cause data loss.

For more information about adding, removing, and moving cache servers, see Managing Cache Servers.

Getting Cache Performance Information

When requested by the support team, you can provide information about caches using the Cache Performance Summary table on the Caches page in the admin console. There, you'll find a list the individual kinds of data cached. Many represent content, such as blog posts and documents. Others represent other data that can be performance-expensive to retrieve from the database.

For each cache, you'll find the following information:

Column Name	Description
Cache Name	You can click the cache name to view advanced statistics about the cache. You might use these statistics when working with the support team to resolve cache-related issues. General information about the advanced statistics is provided below.
Objects	Generally speaking, each object in the cache represents a different instance of the item. For example, if the Blog cache has 22 objects in it, it means that 22 of the community's blogs are represented there.
Hits / Misses	A cache hit is recorded when a query to the cache for the item actually finds it in the cache; a cache miss is when the item isn't found in the cache and the query much go to the database instead. As you might imagine, a higher ratio of hits to misses is more desirable because it means that requests are finding success in the cache, making performance from the user's perspective better.
Effectiveness	The effectiveness number -- a percentage -- is a good single indicator of how well a particular cache is serving your application. When a cache is being cleared often (as might happen if memory constraints are being reached), the ratio of cache hits to misses will be lower.
Clear Cache Check Box	When you're asked to clear a cache, select its check box, then click the Clear Selected button at the bottom of the cache list table.