caching in elasticsearch?

Question

elasticsearch

In my index, I specified index.store.preload: ["*"]To preload data into the file system cache. The entire index occupies 27 Gb, about 45 Gb is allocated for the cache in the system, and all this memory is full, it turns out that not only those 27 Gb, but something else gets into the cache. Is there any way to find out how much space the index will occupy in the cache? Also, I don't understand the difference between file system cache and using indices.fielddata.cache.Which one would be more practical for faster lookups? Does it make sense to use both options?

Answer 1

test and observe