Elastic search server configuration

, could you please let us know the elastic server configuration required based on the below details

  1. Daily log volume shipping to elastic search average is 10-15 G , so average index size is ~30 G with 2 shards

  2. Current configuration with 2 elastic search node is
    a. 8x16 G Ram
    b. 500 G storage

We have tried the doc_value option to resolve the memory issue , seems its impacting the performance of visualization creation . Instead of making this change in production requesting your assistance on setting up correct server infrastructure to avoid further issue