一直困扰于 indexSearcher 的重新 new ,query filter 的cache 没了。

Caching

• Configurable Query Result, Filter, and Document cache instances
• Pluggable Cache implementations
• Cache warming in background
  • When a new searcher is opened, configurable searches are run against it in order to warm it up to avoid slow first hits. During warming, the current searcher handles live requests.
• Autowarming in background
  • The most recently accessed items in the caches of the current searcher are re-populated in the new searcher, enabing high cache hit rates across index/searcher changes.
• Fast/small filter implementation
• User level caching with autowarming support