Cache invalidation after index builds

Types of caches

The HCL Commerce Query and NiFi servers use several HCL caches, as described in HCL Cache Architecture. Most of the data stored in the caches is obtained by querying Elasticsearch indices. When indexed data are changed, the cache entries that used this data must be invalidated so that they can be refreshed with changed index data the next time they are used. For a complete description of the caching subsystem, see HCL Cache.

The default baseCache is different from the other caches. It is a servlet cache that contains cache entries as defined in the cachespec.xml files for the Remote Store server, Transaction server, and Elasticsearch Query application server.

Types of Invalidations

To help decide which cache entries are invalidated when index data changes, cache entries are tagged with dependency Ids.

You can tag cache entries in the baseCache that contain data specific to a category, product, or item in the cachespec.xml file with dependency Ids that include the category, product, or item Id. Use the invalidation template configurations format defined for these dependency Ids in Fine-grained cache invalidation. Cache entries tagged in this way are to be invalidated when index data for those categories, products, and items are changed and corresponding fine grained invalidations are issued. Ensure that these cache entries are also tagged with the "WCT+FULL_ESINDEX" dependency id, which is issued when fine grained invalidations cannot be issued.

Cache entries in the baseCache tagged with the "WCT+FULL_ESINDEX" dependency Id are to be invalidated when a full index rebuild occurs, or when changes are made to the indexed data for which fine grain invalidations are not issued. Cache entries in any of the caches used by the Query and Nifi application servers tagged with the "WCT+ESINDEX" dependency Id are to be invalidated when any change is made to any indexed data.

Index Update Scenarios