Configure Query Caching - SuperWEB2
Query caching is designed to give a performance boost to SuperWEB2 by caching query results.
This means that if the same table is created/tabulated more than once, the tabulation result can be obtained from the cache instead of using SuperSERVER to perform the tabulation.
Cache Options Available in SuperWEB2
SuperWEB2 supports three caching options:
| Cache Strategy | Use When... | Description | Configuration Instructions |
|---|---|---|---|
| CouchBaseMemoryPersistentCache | You want the cache to survive between SuperWEB2 server restarts | This option provides a disk-based persistent cache as well as high performance memory caching once the cache is loaded. To use this option, you need to install Couchbase 1.8.0. This cache strategy is implemented as 2-level caching: once the cache is loaded from the Couchbase server into the Java Virtual Machine (JVM) running SuperWEB2, it will be cached into the LRU map for even faster results without the extra network overheads of making a request to the Couchbase server. In Couchbase server, multiple Memcached Buckets can be defined with an administrator specified quota. If this quota is exhausted, a Memcached Bucket will discard expired or least recently used data to make room for new data. For more information about how Memcached works in Couchbase server, see: http://www.couchbase.com/memcached | Configure CouchBaseMemoryPersistentCache |
LRUMemoryCache (Least Recently Used Memory Cache) | You want to cache results but do not need the cache to persist between restarts | This is a light-version memory cache making use of the Java Virtual Machine (JVM) heap memory available in the same container as the SuperWEB2. This option uses a key-value map data structure with a configurable size to cache query results. When the map is full and a new table result needs to be cached, the least-recently-used cached object is removed and replaced by the new object. All cached objects are lost if the Tomcat server is restarted. | Configure LRUMemoryCache |
| NoCache | You do not want to cache any results | This is the default option that comes with SuperWEB2. No results are cached. |
Clean Up/Refresh the Cache Results
In some cases you may want to update the cache with the latest query result. For example, you might have made some configuration changes to SuperWEB2 or the SXV4 data might have changed.
The steps to refresh the cache depend on the type of caching:
| Cache Strategy | Steps |
|---|---|
| CouchBaseMemoryPersistentCache | The recommended practice for clearing a Couchbase Bucket via the Administrator GUI is to delete and recreate the bucket:
|
| LRUMemoryCache | Stop and restart Tomcat. This will clear all data cached in JVM memory. |
