We are experiencing a problem with ES 5.4.2 on production. About 25% of our indexed documents are only appearing in search results after 3 seconds or more after success response from indexing request. Our cluster consists of three nodes with 59GBs of RAM of which 31GBs are dedicated to ES heap. Heap usage never goes over 75% with GC dropping it down to ~25-30%. Indexing rate is relatively low, less than 10 documents per second. Our average refresh time is ~300 ms. Refresh interval is default 1 s.
With these numbers, I am expecting at most ~1.5 s delay between indexation and search availability. What am I missing here? Is it possible to reduce this search availability delay?
Thank you in advance,