With my current setup of ElasticSearch, I cannot support the memory requirements for the field cache. I was wondering if there has been any thought to turning it off completely.
I have a lot of users perform various facets across quite a bit of data. With our front end UI we restrict the amount of documents they can facet on, and what fields. This lets us keep the memory utilization per facet in check. For example.
Facet #1 - Quick facet
.75 seconds Execution Time
181mb Field Cache size per Node
3.8 bytes per hit in Memory
Facet #2 - Larger Facet
17 seconds Execution Time
4.3gb Field Cache size per Node
Total: 9.5 bytes per hit
Because of this, my cluster is almost guaranteed to go out of memory with cache size for some of the larger facets. I was looking into the documentation, and I can set the max_size to 1, but the code still puts data in the cache, and then evicts it almost immediately.
So i'm wondering if I can just disable the cache entirely. I know the performance is not nearly as fast, but the cluster is stable and has less OutOfMemory issues. We had the exact same problem with Solr, and disabled the field cache as well.