我对 lucene 索引有一些问题。这发生在过去，我重新索引了整个数据，它又发生了。
确实，文件夹中缺少该文件，我不知道它是如何消失的。是否可以在不删除所有内容的情况下将索引恢复到旧状态？
Caused by: org.compass.core.engine.SearchEngineException: Failed to open Lucene reader/searcher; nested exception is org.compass.core.engine.SearchEngineException: Failed to open index searcher for sub-index [ctadoc]; nested exception is org.compass.core.engine.SearchEngineException: Failed to open sub index cache [ctadoc]; nested exception is java.io.FileNotFoundException: /fs/eudract/eudract_ps_index/index/ctadoc/_3npk.cfs (No such file or directory)
提前致谢，亲切的问候