During consulting engagements, I tend to see that Solr users forget or simply don't know how to use filter queries or simple filters. People tend to add another clause with a logical operator to the main query—they forget how efficient filters can be, at least when used wisely. That's why whenever I can, I tell people using Solr to use filter queries. However, when using filter queries, it is nice to know how to set up a cache that is responsible for holding the filter results—the filter cache. This recipe will show you how to properly set up the filter cache.
Remember that the cache usage is dependent on your queries, update rates, searcher reopening, and so on. In this recipe, you will see cache configuration based on some assumptions; however, you will see the logic behind choosing the right cache configuration. You can use the same logic to adjust caches in your Solr deployment.
Also remember that the filter cache in Solr is a top-level cache,...